Dissertations / Theses on the topic 'Exercise – Physiological aspects'
To see the other types of publications on this topic, follow the link: Exercise – Physiological aspects.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Exercise – Physiological aspects.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Swartz, Ann M. "A comparison of the health and fitness benefits received with varying quantities of energy expenditure." Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1115731.
Full textAbstract:
The Surgeon General's Report on Physical Activity and Health recommends expending 200 kcals "on most, if not all days of the week" (1000 to 1400 kcals/week) as a minimum quantity of exercise energy expenditure (EE) required to obtain health benefits. The ACSM recommends expending a minimum of 1000 kcals/week to receive fitness benefits. The purpose of this study was to evaluate the effect of EE above and below 1200 kcals/week on health and fitness benefits. Twenty-six previously sedentary males and females (mean age = 47 ± 2 years), with at least one risk factor for CAD completed the 22-32 week endurance exercise training study. Subjects performed an initial health screening and treadmill test which included measures of heart rate, blood pressure, blood lipids, body composition at rest, and metabolic data (V02, VE, RER) during the maximal treadmill test. Subjects began exercising with the Adult Physical Fitness Program at a self-selected amount of energy expenditure, recording heart rate, frequency, and duration of exercise on an exercise log card after every exercise session. After 22-32 weeks, subjects returned to the laboratory for a final evaluation identical to the first. The metabolic data from the initial and final tests, along with the data from the exercise log card was used to develop an estimation of energy expenditure/week. Subjects were then categorized into either < or > 1200 kcal/week energy expenditure. Results of the pre/post (n=12) training blood pressure, blood lipids, body composition and V02 __ measures were:EE <1200 kcalsEE >1200 kcalsVariablePre TrainingPost TrainingPre Training 'PostTrainingVO2.(L/min)2.287+.1982.397±.1983.064±.2073.290±.210VO2.(ml/kg/min)27.4+1.7-28.2+1.7-33.0+2.4-37.3±2.6 #HDL-C(mg/dl)51+4.355±4.547±2.850±3.2SBP(mmHg)121±4117±3124±4y120±37BMI(k g/m2)28.0±1.728.3+1.731.2+1.6730.0+1.5y #*p <0.05 training main effect, #p < 0.05 group by time interaction, y: n=14The group that expended above 1200 kcals/week displayed more improvement inrelative V02 n,.,., and BMI following the training program than the group thatexpended less than 1200 kcals/week. Furthermore, there was a training main effect showing adaptations in V02 ., HDL and SBP. In conclusion, previously at risk, sedentary individuals exercise training > 2 days/week can receive health and fitness benefits. However, those expending more than 1200 kcals/week will receive a greater benefit in terms of body composition and cardiovascular fitness.School of Physical Education
2
Hart, Linda E. "The influence of a single session of aerobic exercise on blood pressure during daily activities." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08182009-040432/.
Full text
3
Xu, Fan 1960. "Effect of prolonged exercise on running economy." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68149.
Full textAbstract:
The purpose of this study was to investigate the effect of prolonged exercise on running economy. Fourteen male long distance runners performed two 90 minute runs on an outdoor 400m track at velocities equal to 65 and 80% of VO$ sb2$max. Prior to and following each 90 minute run, running economy (RE) was measured as the steady-state VO$ sb2$ during treadmill runs at speeds of 188 and 228 m/min. During the 90-min run at 65% of VO$ sb2$max, the mean weight loss was 1.3 kg. The HR was 143 bpm between minutes 5-10 and increased to 150 bpm between minutes 85-90. During the 90-min run at 80% of VO$ sb2$max, the mean weight loss was 1.4 kg. The HR was 161 bpm between minutes 5-10 and increased to 165 bpm between minutes 85-90. When the post RE test was conducted following each 90-min run, there was a significant increase in VO$ sb2$ expressed in both l/min and ml/kg$ cdot$min (a decrease in running economy). The increase in oxygen cost of running following the 90-min run at 80% of VO$ sb2$max was greater than that following the run at 65% of VO$ sb2$max.
4
Scordo, Kristine A. Bludau. "The effects of aerobic exercise training on symptomatic females with mitral valve prolapse syndrome." Connect to resource, 1990. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1244145517.
Full text
5
Bozac, Anna Elena. "Determining exogenous glucose oxidation during moderate exercise." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28736.
Full textAbstract:
The purpose of this study was to determine the quantity of a glucose drink oxidized during cycle ergometer exercise at 60% VO₂max for 75 minutes. A second purpose was to determine if the glucose drink improved sprint time to exhaustion at 90% VO₂max after 75 minutes of exercise. Six trained male cyclists (VO₂max > 60 ml•kg⁻¹•min•¹) exercised on three occasions during which they ingested either water ad lib (W), ¹³C-cornsyrup (100 g, 2.02 M) + water ad lib (CS), or NaH¹²CO₃/NaH¹³CO₃ mixture (5 mg•kg⁻¹, 1% ¹³C-enriched) + water ad lib (B). Treatments B and CS were ingested after 5 minutes of cycling at 60% VO₂max. During exercise, there was no difference between treatments in plasma lactate response, changes in plasma volume, sprint time to exhaustion, or in respiratory exchange ratio (RER), VO₂, or VCO₂. RER showed a significant decline (p< .01) from 5 minutes (1.00±0.05, X±SD) to 75 minutes (0.96±0.05), and VO₂ showed a significant positive shift (p< .01) from 3.15(±0.29) to 3.52(±0.45) l•min⁻¹. A transient rise in plasma glucose was observed with CS. Changes from rest in ¹³C/¹²C ratio (∂13C) showed a significant increase (p< .01) following CS. Peak glucose oxidation rate was 7.26 g•15 min⁻¹ which occurred after 75 minutes. Total dose of exogenous ¹³C-glucose recovered as ¹³CO₂ (above baseline) was 22%. These observations suggest that (1) during moderate exercise of 75 minutes duration, oxidation of exogenous glucose occurs within 15 minutes but contributes marginally to total carbohydrate utilization as RER continued to fall with or without CS, and (2) sprint time to exhaustion after 75 minutes of cycling is not improved with glucose ingestion.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
6
Conley, Travis B. "Growth response to resistance exercise : influence of exercise device." Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1395457.
Full textAbstract:
The purpose of this study was to compare the growth response elicited by an acute bout of resistance exercise (RE) conducted on a traditional weight stack device (WS) and a flywheel device (FW). Eight recreationally trained males (25 ± 9 y, 77 ± 27 kg) performed 4 sets of 7 repetitions of bilateral knee extension on each exercise device separated by 7 days. Muscle biopsies were obtained from the vastus lateralis at rest and 4 hrs post-exercise to examine the expression of selected myogenic and proteolytic genes. RE increased (P < 0.05) mRNA expression of Myogenin (3.6 vs. 3.6 fold), and MyoD (2.2 vs. 2.0 fold) and decreased (P < 0.05) expression of Myostatin (1.4 vs. 1.5 fold) to a similar degree on both exercise devices. There was no change in the expression of Atrogin-1, MuRF-1 or MRF4 following RE on either device. The only device mediated difference in the expression of the selected genes was observed in Atrogin-1 which was lower following RE on the FW versus the WS device. The current data shows that in the initial hrs following RE, use of the FW is as effective as the traditional resistance training devices (WS) in promoting the induction of genes involved with muscle remodeling and growth.School of Physical Education, Sport, and Exercise Science
7
Reardon, Constance R. "Exercise and premenstrual syndrome." Virtual Press, 1986. http://liblink.bsu.edu/uhtbin/catkey/471854.
Full textAbstract:
Premenstrual syndrome (PMS) is a term used to describe a number of symptoms affecting women approximately two weeks prior to menstruation, and ceasing with the onset of menstrual flow. The general physiological and psychological adaptations to training suggest that physical activity could lessen some PMS symptoms. Therefore, the purpose of this study was twofold: 1) to compare the number of PMS symptoms of intercollegiate athletes with those of sedentary college age women, and 2) to determine if training reduced the severity of PMS symptoms in a group of previously sedentary women.In study #1, a PMS questionnaire was distributed to female athletes representing six teams (n=92), and sedentary female athletes (n=47) at Ball State University. A one-way analysis of variance revealed that there was no significant difference (p>.05) in occurance of symptoms between the athletes and the sedentary females.In study #2, 13 sedentary women (X age= 34.6 + 1.9) suffering from PMS, participated in a four month study to determine if training would reduce the severity of their PMS symptoms. Eight women comprised the training group, and participated in 30-40 minutes of aerobic exercise four times per week. The control group consisted of five women who remained inactive. A correlated t-test revealed a significant increase (p<.Ol) in maximal oxygen uptake and a significant decrease (p<.Ol) in PMS symptoms after four months of activity in the experimental treatment group. The control group showed no significant changes (p>.05) in maximal oxygen uptake or PMS symptoms during the four months of the investigation. Based on the data from this study, it was concluded that women with PMS have significant decreases in mood swings, appetite, cravings for sweets, breast tenderness, anxiety and depression after training.
8
Lee, Jonah D. "The effects of pre-exercise carbohydrate supplementation on anaerobic exercise performance in adolescent males." Virtual Press, 2007. http://liblink.bsu.edu/uhtbin/catkey/1366300.
Full textAbstract:
This study examined the effects of pre-exercise carbohydrate (CHO) supplementation on anaerobic exercise performance in adolescent males (n =11; 15.0 ± 0.9 yrs). On separate days, subjects consumed either a CHO or a placebo (PL) beverage followed by 2 Wingate anaerobic tests (WAnT) separated with ten by 10-second sprints. Peak (PP), mean power (MP) and fatigue index (FI) were assessed. Venous blood samples were obtained and analyzed for glucose, lactate, insulin, and catecholamines. A trial by time ANOVA (P < 0.05) was used in the analysis. PP and MP tended to be higher (P < 0.09) in CHO versus PL, and MP tended to decline more in CHO (P < 0.06); Fl for the two WAnT were similar. Glucose concentration significantly increased after CHO consumption and then returned to baseline post-exercise, whereas glucose level remained unchanged over time during PL; similarly observed for insulin. Lactate and catecholamine levels significantly increased over time, but a trial difference was only observed in epinephrine. The tendency for PP and MP to be higher in CHO might suggest a potential ergogenic benefit of pre-exercise CHO although the change in MP over time in CHO and the similarity in Fl might suggest otherwise.School of Physical Education, Sport, and Exercise Science
9
Hasson, Christopher J. "Neural and mechanical influences on the initation of the squat jump." Virtual Press, 2003. http://liblink.bsu.edu/uhtbin/catkey/1260619.
Full textAbstract:
The purpose of this research was to examine the effects of a premovement silent period (PSP), and an involuntary small amplitude countermovement (CM) on the maximal height of the squat jump (SJ). Fifteen elite male volleyball players (20.6 ± 1.6 yrs) and thirteen untrained males (20.2 ± 1.7 yrs) performed ten maximal effort SJs from identical starting positions. The electromyographic activity of the vastus lateralis and biceps femoris was measured in conjunction with the vertical ground reaction force, and the vertical displacement measured by a cable-extension transducer. The presence of a PSP or small amplitude CM did not increase maximal SJ height significantly (p > 0.05). These findings indicate that in the SJ, facilitation effects of the PSP and small amplitude CM are minimal. This is important to past and future studies utilizing the SJ, as it is often difficult for individuals to perform SJs with no detectable CM.School of Physical Education
10
Burns, Jennifer Marie. "Effects of choline ingestion on endurance performance." Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/539635.
Full textAbstract:
Plasma choline levels have been reported to be significantly reduced in athletes at the endof prolonged, exhaustive exercise (marathon running), and this may affect the release of acetylcholine at the neuromuscular junction (16). The purpose of the present investigation was to examine the influence of two levels of choline (from soy lecithin) ingestion on plasma choline levels and exercise performance. Ten endurance-trained male cyclists exercised on an electrically resisted ergometer for 105 minutes at a load equal to 70% V02 max, followed by an all-out, self-paced 15 minute performance ride on an isokinetic cycle. Three randomly ordered trials were performed four hours after the feedings of (A) 0.0 g, (B) 1.1 g, or (C) 1.8 g choline. Dietary intake of choline was controlled. Before and after the trials, blood samples were drawn and analyzed for serum choline (umol/liter) using an HPLC method. Feedings of 1.1 g and 1.8 g of choline significantly (p < 0.05) elevated serum choline values compared to control (A = 34.16 [± 0.63], B 38.17 [+ 0.96], and C = 42.32 [+ 0.59]).Post-exercise serum choline values, however, were not significantly different (p > 0.05) from pre-exercise levels. In addition, there were no significant differences (p > 0.05) in performance between placebo, 1.1 g, and 1.8 choline trials (2.11 x 105, 2.07 x 105, 2.07 x 105 Newton-meters, respectively). This study indicates a dose response to choline ingestion, with no effect on performance.School of Physical Education
11
Young, Ingrid Victoria. "The energy demands of a 2,000 meter race simulation for national level oarswomen." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28542.
Full textAbstract:
The purpose of this study was to assess the energy demands of a 2,000 meter race simulation (RS) for national level oarswomen; as evaluated on a rowing ergometer (RE). A Progressive Intensity Test (P.I.T.) was also performed on the RE to further evaluate the RS. Six national level oarswomen (X values: age= 24.5 yrs., ht= 179 cm, wt= 75 kg), all current national team candidates (1988), participated in this investigation. A 6 1/2 minute tape recorded water race was used to execute a 2,000 meter RS on a Dr. Gjessing Ergorow ergometer. The tape recording was an actual race tape that was respliced to last exactly 6 1/2 minutes. Metabolic and respiratory exchange variables were continuously monitored by an open circuit method, utilizing a Beckman Metabolic Measurement Cart interfaced on-line with a Hewlitt Packard 3052A data acquisition system. The energy demands were calculated from metabolic variables, total oxygen cost and the analysis of excess post-exercise oxygen consumption (recovery V0₂).Results indicated a mean V0₂max. of 3.85 1.min⁻¹ , mean net V0₂ of 24.48 1 and a mean recovery V0₂ of 4.92 1. This represented the aerobic cost of the event at approximately 80% or 4/5ths of the total energy cost while the anaerobic contribution was approximately 20% of l/5th of the total energy cost. During the RS, V0₂ values rapidly increased to 90% of mean V0₂max. (3.85 l.min⁻¹) in the first two minutes. Mean max. VE (BTPS) RS value was 122.4 1.min⁻¹. VE plateaued after two minutes and remained around 90% of P.I.T. mean max. VE for the final 4 1/2 minutes. Mean max. excess C0₂ for RS was 19.81 ml.kg⁻¹.min⁻¹. The average maximal heart rate, as recorded in the RS was 192.8 bpm. The results of this study indicate the high aerobic demands and tremendous exercise intensity involved in the 2,000 meter RS.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
12
Douglass, Matthew D. "Age and muscle function : impact of aerobic exercise." Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1391476.
Full textAbstract:
The purpose of this investigation was to comprehensively examine the influence of progressive aerobic exercise training on whole muscle size and function in older women (65-80 yr). Three sedentary, healthy, females (66±1 yrs, 167±2 cm, 70±7 kg) performed 12 weeks of supervised progressive cycle training (42 training sessions 3-4 sessions/week up to 80% HRR). Subjects were tested before and after training for maximum aerobic capacity (VO2max), quadriceps cross sectional area (CSA), whole muscle specific tension, concentric 1-RM, maximum voluntary contraction (MVC), and concentric peak power (wafts). On average, the three subjects improved VO2max (34%), quadriceps CSA (10%), MVC (37%), whole muscle specific tension (25%), and concentric peak power (19%). These positive changes indicate that aerobic exercise may positively influence muscle size and function in the elderly.School of Physical Education, Sport, and Exercise Science
13
Kerr, Morag Graham. "Biochemical and physiological aspects of endurance exercise in the horse." Thesis, University of Glasgow, 1985. http://theses.gla.ac.uk/3993/.
Full textAbstract:
A number of biochemical and haematological changes are known to occur in horses involved in long distance riding competitions of 40- 160 km, particularly changes associated with disturbances in fluid/ electrolyte balance, catabolism of body fuel stores and alterations in the integrity of the muscle cell membrane. This study investigated these changes in more detail in 50 horses involved in competitive rides and in four horses undergoing two 80 km rides under controlled conditions. In addition, experiments were carried out on horses and ponies exposed to a hot, humid environment (41°C, 33°C wet bulb) and during intravenous adrenaline infusion, in order to study further the fluid/ electrolyte alterations associated with sweating and in particular the composition of equine sweat. Changes in plasma and urine biochemistry were also studied over 24 hours in horses at rest for comparative purposes. Significant changes were shown in 13 of the 14 plasma parameters measured in the resting horses. Most of these could be related to feeding, in particular to hay feeding which caused alterations in fluid/ electrolyte balance associated with salivary secretion. Urine composition changed very markedly during the 24 hours. Urine flow rate and creatinine and urea excretion were higher during the day and increased following drinking, as in man. Urine potassium and chloride excretion were much higher than sodium excretion and all three electrolytes (and pH, which was alkaline) showed diurnal variations markedly different from those in man. The competing endurance horses demonstrated moderate haemoconcentration, but plasma electrolyte alterations, particularly an increase in sodium concentration, were not always consistent with the production of apparently hypertonic sweat. The pattern of fuel utilisation was one of exhaustion of liver glycogen after about 40 km with extensive fat mobilisation and the use of glycerol for gluconeogenesis. Breakdown of phosphocreatine was extensive and evidence of protein catabolism was observed. Large variable increases in plasma CK and AST activities unassociated with fatigue suggested a non-pathological alteration in muscle cell membrane integrity in a number of horses. During heat exposure changes in PCV and plasma proteins were poorly related to fluid losses but changes in electrolyte concentrations were consistent with the sweat tonicity. Hypertonic chloride and potassium, and isotonic sodium concentrations (relative to plasma) were maintained in the sweat for 4.5 hours. In contrast sweat magnesium and protein concentrations were initially high but decreased exponentially with time. There was a very close correlation between these two parameters. Most of the changes in plasma parameters seen during adrenaline infusion were attributable to the adrenaline per se, but the profuse sweating induced in the horses caused some haemoconcentration. Small ponies sweated much less in response to adrenaline than Thoroughbred horses. Hypertonic sweat concentrations of chloride, sodium and potassium were maintained for 3 hours and significant differences, particularly in Na/K ratio, were found between heat and adrenalineinduced sweat. Sweat urea concentration was related to plasma urea concentration and glucose appeared in the sweat when the plasma glucose concentration exceeded 10 - 12 mmol/l. The sweat magnesium was not protein-bound and the two main electrophoretic fractions of the sweat protein were not present in serum. The possible function of this protein as a wetting agent was discussed. During the controlled 80 km rides total fluid loss was 33.5% of the total ECF volume: 78% of this was sweat and 22% respiratory evaporation. Although sweat electrolyte concentrations were again hypertonic to plasma, theoretical concentrations in total body (sweat plus respiratory) water loss were much closer to plasma concentrations - slightly hypotonic for sodium, slightly hypertonic for chloride. As a result changes in plasma electrolyte concentrations were small, an increase of 9 mmol/1 (5.7%) in sodium and a decrease of 4 mmol/l (3.5%) in chloride. Potassium appeared to move out of the intracellular fluid at the start of exercise and back in immediately afterwards and this obscured any effect of sweat losses on plasma concentration. The only urinary constituent which was conserved in the exercising horses was chloride, and the absence of any decrease in urea excretion suggested that the increase in plasma urea concentration was due to increased protein catabolism, probably from the liver. Body fuel utilisation was similar to that seen in the competing horses and plasma CK and AST activities again suggested that a non-pathological disruption of muscle cell membrane integrity was occurring in some horses which continued intermittently for several months. It was concluded that in the horse, unlike man, the thermoregulatory fluid is approximately isotonic to plasma, which minimises electrolyte imbalances and allows prolonged exercise with less need for drinking. After exercise the large caecum and colon and the sodium contained in them appear to be important in the controlled replacement of the extensive water and electrolyte losses which result.
14
Flynn, Michael Gerald. "Fat storage in athletes : the metabolic and hormonal responses to swimming and running exercise." Virtual Press, 1987. http://liblink.bsu.edu/uhtbin/catkey/516210.
Full textAbstract:
Despite similar rates of energy expenditure during training, competitive swimmers have been shown to store significantly greater amounts of body fat than competitive runners. In an attempt to explain these discrepancies, male collegiate swimmers (n=8) and runners (n=8) were monitored during 45 min of swimming and running, respectively (75% V02 max), and during two hours of recovery. In addition, a group of male competitive triathletes (n=6) were similarly monitored during and after both swimming and running exercise.Blood samples were obtained after 15 min rest prior to exercise and at 0, 15, 30, 60 and 120 min of recovery and were analyzed for glucose, lactate, glycerol, free fatty acids, insulin, glucagons, norepinephrine (NE) and epinephrine (E). Respiratory gases were collected at 15 min intervals during exercise and at 15, 30, 45, 60, 90 and 120 min of recovery. Heart rate and mean body temperature were recorded at 10 min intervals throughout recovery. There were no differences in post-exercise oxygen consumption or heart rate while the RER suggested increased fat oxidation after exercise for the swimmers and the swimming triathletes. The mean body temperature and mean skin temperatures were significantly lower throughout 120 min of recovery for the swimmers compared to the runners. The triathletes demonstrated a similar tendency but these differences were not significant. The serum glucose levels were significantly greater (P<0.05) immediately post-exercise for the runners compared to the swimmers (6.71 +0.29 and 4.97 +0.19 mmol•1-1, respectively). Blood glucose values were also significantly greater immediately post-run for the triathletes (6.40 +0.26 and 4.87 ±0.18 mmol-l-1 for running and swimming, respectively). Blood glucose values remained elevated for runners and the running triathletes up to 30 min of recovery. Free fatty acids were similar after the run and the swim, but glycerols were increased immediately after running in the runners (P<0.05) and the triathletes (P<0.05). Differences in blood glucose levels or fat release were not explained by differences in NE, E or cortisol. The glucagon-to-insulin (G:I) ratio was significantly increased after exercise in the swimmers and the swimming triathletes. This, combined with a reduced RER after the swimming trials, suggests that the reduced glucose levels were due to reduced hepatic glycogen stores. The results of this study suggest that there were differences in substrate utilization during running and swimming exercise of the same intensity. These differences were not explained by NE, E or cortisol; however, the increased G:T ratio suggests increased carbohydrate use during exercise in the swimmers. Finally, body fat differences between runners and swimmers were not explained by differences in post-exercise energy expenditure or fat oxidation.
15
Cacija, Gordana. "Expertise and training effects on co-ordination dynamics in a whole body rhythmical task." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2003. https://ro.ecu.edu.au/theses/1330.
Full textAbstract:
This research consists of two studies. The purpose was to investigate the effects of slow and fast music tempo on interjoint co-ordination variability in an aerobic stepping task. The 'step knee-up' task is a cyclical whole body movement performed on the step platform. The exercise consisted of a few repetitive cycles. A cycle was defined by eight counts, four counts for the left leg pattern and four for the right leg as follows: The first half of the cycle was counted: I. Step up with the left foot onto the 20-cm step platform, 2. Flex the right hip to bring the right knee up; 3. Step down to the floor with the right foot and, 4.Tap once with the left foot on the floor near the right foot. The second half of the cycle consisted of the following four counts: I. Step up onto the platform with the right foot; 2. Flex the left hip to bring the left knee up. 3. Step down to the floor with the left foot and, 4. Tap once with the right foot on the floor near the right foot. The participants were instructed to move both arms simultaneously forward and backward so that the limbs would perform in-phase movement, which is opposite to the natural anti-phase arm movements that accompanies walking and stepping activities. This pattern of the arm movements has been defined as a proposed pattern or the 'to-be-learned' pattern. In particular, the research examined to what extent unskilled and skilled participants would adjust their movement co-ordination to cope with changes in performance conditions in attempting to achieve the criterion task. In the first study, these effects were observed in novices and experts, while the effects of the fast tempo training on intrinsic dynamics (self-paced condition) were considered in the second study. Both studies were based on the Dynamic Systems Theory. The environmental factor, which was considered as the control parameter affecting performance in both studies, was the music tempo. In the first study interjoint co-ordination responses were analysed in terms of a version of the Haken, Kelso and Bunz's (HKB) modal that considers detuning or frequency competition terms. Six novice and six expert females participated in the experiment performing a 'step-knee-up', a whole body rhythmical task, under different music tempos. They were tested at a slow tempo at 48 beat/min and at a fast tempo of 144 beat/min. Two hypotheses were proposed. Firstly, it was hypothesised that discrete relative phase variability of inter-joints co-ordination would be higher.at the fast tempo then at the slow tempo in both, novices and experts. It was further hypothesised that, in order to cope with changes in performance conditions and still achieve the criterion task, novices would demonstrate higher variability than experts at both the slow and fast tempo. Results showed that interjoint co-ordination in experts was more consistent (less variable) at both the slow and fast tempo compared to novices, in all couplings expect in the left leg. Furthermore, follow-up tests revealed that Tempo and Side effects in novices were not significant. In experts, however significant Side effect was found in shoulder joint coupling and hip-knee joint coupling. Higher variability was found in left leg interjoint coupling between hip and knee joints at both tempos, compared to the right leg. In shoulders joint coupling, however, higher variability was found only in the slow tempo for the right side observation of the L Shoulder-R Shoulder movement. Finally, it was observed that the initially specified arm movement direction (iso directional or in-phase movement) changed to anti-phase direction at fast tempo in novices. Therefore, in novices, in-phase arm movements were more sensitive to fast tempo perturbations compared to anti-phase. While these results may be in contrast to Haken, Kelso and Bunz's model predictions they are partly supported by Whittal, Forester and Song's (1999) findings. In the second study, whether practising the task under the fast music tempo would affect the interjoint co-ordination stability at the preferred tempo performance (without the music) was investigated. It was hypothesised that, after the training under the fast music tempo interjoint coupling variability at the preferred tempo would decrease. The hypothesis was partly accepted as variability decreased in the self- paced condition after training only in shoulder-shoulder interjoint couplings compared to the self-paced condition before training. Results in the second study were discussed in relation to Shaner and Kelso's (1988) dynamical theory of environmental function and motor learning transfer principles. It was found that training under the fast tempo did not significantly affect overall performance at self-paced and fast tempos. However, different changes in interjoint co-ordination strength were observed in different couplings before and after training as the function of (the left or right) body side. It was concluded that interjoint co-ordination flexibility is highly specific to the interaction between the task, body side, performance condition and skill level. Finally it was suggested that an individual approach to the analysis of variability in co-ordination dynamics in skilled and unskilled performance and learning be considered.
16
Linton, Darla K. "The comparative effects of a 12-week high impact aerobic dance and bench step training program on isokinetic strength, power, and endurance of the quadriceps." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06112009-063042/.
Full text
17
Meiring, Joseph R. "The influence of rest-interval duration on the growth hormone response to resistance exercise." Virtual Press, 2006. http://liblink.bsu.edu/uhtbin/catkey/1356252.
Full textAbstract:
The purpose of this study was to establish an exercise protocol that demonstrated a relationship between rest-interval duration and the exercise induced human growth hormone (hGH) response. Ten recreationally trained male subjects (23 ± 0.9 yrs) performed three leg extension trials on an Eagle — Cybex leg extension machine that consisted of 4 sets of 10 repetitions. The workload and volume was kept constant, but each trial had different rest-interval durations. Rest-interval durations between sets were at: 30 sec intervals (T-30), 60 sec intervals (T-60), or 120 sec intervals (T-120). Blood samples were obtained pre- and 0 — 30 minutes post-exercise and analyzed for lactate and hGH. All blood lactates rose significantly above baseline after exercise, with no differences in time of occurrence between trials. Blood lactates were significantly greater after the T-30 trials, compared to that of the T-60 and T-120 trials. There was no significant difference in hGH concentrations between trials. However, the data did suggest a relationship between rest-interval duration and the variability of hGH responses. The T-30 trials yielded significantly greater variation in hGH concentrations than the T-120 trials, and the T-120 trials showed significantly less variation than both the T-30 and T-60 trials. Although significant differences were found in these variations between trials, they did not prevent any significant differences in concentrations between trials from being found. In summary, the results of this study demonstrated an exercise related increase in lactic acid that had an inverse relationship to the length of the rest-intervals. hGH data on the other hand, did not show a relationship between rest-interval duration and the hGH concentrations. The connection between rest-interval duration and variability of hGH responses could possibly suggest that hGH values may have been significantly different if an exercise protocol higher in volume were utilized. Additionally, the results indicate that there is no direct relationship between blood lactate and hGH concentrations, as others have suggested.School of Physical Education, Sport, and Exercise Science
18
Houmard, Joseph A. "Rate of heat acclimation : effects of exercise intensity and duration." Virtual Press, 1988. http://liblink.bsu.edu/uhtbin/catkey/533882.
Full text
19
Artale, Lisa M. "The effects of physical activity on aging : a longitudinal analysis." Virtual Press, 1998. http://liblink.bsu.edu/uhtbin/catkey/1115727.
Full textAbstract:
The purpose of this study was to examine the participants of the Ball State University Retirees Fitness (BSURF) program in order to determine the role that habitual participation in an exercise program plays on the aging process. The participants of the BSURF program were divided into two groups: those that have been exercising for seven or more years (LT; n=14), and those that have been exercising for six years or less (ST; n=10). Subjects underwent testing on the following variables: BMI, body composition, resting heart rate and blood pressure, blood lipid profile, biceps muscular strength, trunk flexibility, and the Rockport Walk Test. Group differences were determined using an independent t-test. Despite a significant difference in age and duration of participation time between the LT and ST groups, no statistically significant differences in cardiovascular measurements, anthropometric measurements, and body size were seen between the two study groups. The only exception to the positive effects of this exercise program on the aging process is demonstrated by the trunk flexibility data. The ST group was significantly more flexible (27.6 ± 1.51 cm) than the LT group (17.7 ± 2.67 cm). The results of this study suggest that continued participation in the BSURF program enabled the LT group to maintain their physiological functioning. Further, the length of participation by the members of the BSURF program clearly demonstrates significant adherence, and suggests that a program of moderate intensity in combination with a large social aspect may play a role in the exercise adherence of older adults.School of Physical Education
20
McConaghy, Finola Frances. "Aspects of thermoregulation in the horse during exercise." Thesis, Department of Animal Health, 1996. http://hdl.handle.net/2123/13121.
Full text
21
Howe, Cheryl A. "The effects of warm-up intensity on anaerobic performance and metabolic recovery in male children." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/917031.
Full textAbstract:
The purpose of this study was to examine the effects of warm-up intensity on anaerobic performance and recovery in children. Six male children (11.0 ± 0.6 yr) performed an IAT following a mild (85% of VAT), intense (115% of VAT), or no warm-up protocol. VAT was determined during a previously performed GXT. A catheter allowed for multiple blood samples drawn thoughout each trial. Performance indices, PP, MP, TW, and FI%, were not significantly different across trials. Blood analysis revealed significant interactions for recovery [LA] and [HC03-], although no significant interaction for pH values. There was also a significant interaction for V02 recovery pattern. The ALA (5.2 vs. 7.1 mmol•1-1, respectively) and AHC03- (6.1 vs. 8.4 mmol-l-1, respectively) were significantly lower for the AVAT trial compared to NWU trial. These data indicate that the AVAT warm-up resulted in less acid-base balance disturbance suggesting greater dependence on aerobic metabolism during the IAT.School of Physical Education
22
Tatum, JoLyn Inez. "The Relationship between Physical Activity and Sleep." Thesis, University of North Texas, 2010. https://digital.library.unt.edu/ark:/67531/metadc30518/.
Full textAbstract:
The current study aimed to examine the naturalistic relationship between physical activity and sleep by exploring frequency, type, and timing of exercise and their association with a variety of sleep variables (e.g., sleep onset latency, wake after sleep onset, sleep efficiency). Young adults (n = 1003) completed a variety of self-report questionnaires, including a week-long sleep diary and a survey of typical frequency, type, and timing of exercise completed in the past week. Increased frequency of physical activity was related to increased sleep efficiency (total sleep time/time in bed), decreased time in bed, and decreased time spent awake in bed in the morning. Greater amounts of exercise energy expenditure (i.e., metabolic equivalents) per week was related to increased sleep efficiency, and decreased time in bed and time spent awake in bed in the morning. After controlling for other factors, this relationship remained true only for time spent awake in bed in the morning. Early morning exercisers reported shorter total sleep time and time in bed than those who typically exercised at other times. No exercise differences were found between those who met the research diagnostic criteria for insomnia and those who did not. This study provides valuable information to help guide future experimental and intervention studies.
23
Zachwieja, Jeffrey J. "Influence of carbohydrate feeding during exercise on muscle glycogen synthesis after exercise." Virtual Press, 1991. http://liblink.bsu.edu/uhtbin/catkey/776705.
Full text
24
Cranston, Tracy E. "The effect of exercise training on the severity and duration of an upper respiratory tract infection." Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/941357.
Full textAbstract:
Although upper respiratory tract infections (URTI) are the most frequent illness among humans, insufficient evidence exists to determine if exercise training during an URTI may prolong or intensify an URTI. The purpose of this investigation was to determine the effect of exercise training on the severity and duration of URTI symptoms. Following serological screening, those subjects who were rhinovirus 16 (RV 16) antibody-free completed a graded exercise test. Thirty-four individuals (ages 18-29 years) of moderate fitness (between 32 ml/kg"1/miri 1- 60 ml/kg 1/min"1) were randomly assigned to the exercise group (EX) while 16 individuals of similar age served as a nonexercise control group (CTL). All subjects were inoculated with RV 16 on two consecutive days. EX subjects completed 40 minutes of supervised exercise at 70% of heart rate reserve within 18 hours of each inoculation and then exercised every other day for the next eight days (total of six exercise sessions). Immediately following each exercise period subjects completed a symptom checklist. EX subjects were strongly encouraged to abstain from any additional physical activity while the CTL group was encouraged to be as sedentary as possible for ten days beginning the first day of inoculation. Prior to the first inoculation and every 12 hours afterwards all subjects completed a 13 item symptom severity checklist and a physical activity log (e.g., minutes of walking, and hours of work). Used facial tissues were collected and weighed during these same reporting periods. One-way analysis of variance indicated that there! was no significant difference between groups with respect to additional physical activity. Two-way analysis of variance indicated that there were no significant differences in either the severity or duration of an URTI (symptom scores, mucous weights) between the EX and CTL groups for any given day. Further, no significant differences were observed between the pre and post exercise symptom scores for the EX group. These results suggests that moderate exercise training during a rhinovirus-caused URTI does not appear to alter the severity and duration of the illness. This was the first study to examine the influence of exercise on symptom severity and duration during an URTI. Additional studies should be performed utilizing various exercise prescriptions (e.g. intensity, frequency and duration), subject populations (e.g. younger and older), and fitness levels (e.g. sedentary, and highly fit).School of Physical Education
25
Demchak, Timothy J. "The effects of upper respiratory illness on running mechanics during a VOb2s maximal treadmill test." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/917030.
Full textAbstract:
The purpose of this study was to determine the effects of an upper respiratory illness (URI) on running mechanics during a maximal VO2 exercise treadmill test. The specific measurements assessed were stride length (SL), stride frequency (SF), range of motion (ROM) of the hip, knee, and ankle, and the displacement of the center of mass (COM) during the stride cycle. Fifty-three subjects (female=25, male=28) between 18 and 30 years of age completed the study. The participants in the study were characteristically non-smokers, drank fewer than five alcoholic drinks per week, had no orthopedic problems, were not pregnant, did not suffer from hay fever or chronic colds, and were not allergic to penicillin. Rhinovirus Type 16 was used in the inoculation of the individuals. The subjects performed two maximal V02 treadmill test. The first test was before the inoculations and the second test was during the height of the illness. Stride length and SF data were derived from accelerometer data. Statistical analysis using ANOVA revealed no significant changes in SL or SF between pre- and post-inoculation treadmill tests. Based on the results of this study it was concluded that Rhinovirus Type 16 does not effect running mechanics during a maximal V02 treadmill test.School of Physical Education
26
Anderson, Beth Naomi. "The effects of an upper respiratory infection on resting pulmonary function and physiological responses during graded exercise in young adults." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/902472.
Full textAbstract:
Viral illnesses are the most common agents affecting humans. Due to their widespread affects, viruses may have a particular influence on exercise functional capacity. Therefore, the purpose of this study was to determine the impact of an Upper Respiratory Infection (URI) on exercise functional capacity, as measured by VO2max. In addition, submaximal exercise responses, changes in resting pulmonary function, the impact of select symptoms, and level of initial fitness on performance during an URI were also determined. Forty-five subjects (females=21, male=24) between 18 and 29 years of age participated in this study and were assigned to a mild or severe illness group based on symptom severity. There was also a control group of 10 subjects (female=5, male=5). An initial serological screening was performed on all experimental subjects to assess for the RV16 antibody.Subjects testing negative for the antibody performed a baseline graded exercise test to volitional fatigue, as well as pulmonary function tests. Each subject was inoculated two consecutive days with the RV16 virus within ten days of the baseline exercise test. The day following the second inoculation (peak illness) the subjects performed post-pulmonary function and exercise tests. The control subjects performed two resting pulmonary function and exercise tests separated by one week. Significance was set at p<0.05. Repeated measures ANOVA revealed a significant interaction in V02 at submaximal and maximal levels between trials for all groups (p<0.045). A significant interaction for VE for all levels and all groups was found (p<0.002). No impairment in resting pulmonary function was observed. Analyses of symptoms, and initial V02 in regard to performance, also revealed no significant differences. Therefore, the results seem to indicate that an URI does not limit one's ability to perform at submaximal or maximal levels of exercise, however, some relationship seems to exist. Further research is needed to clarify the effects of an URI on physical performance.School of Physical Education
27
Fielding, Roger A. "Pre-exercise carbohydrate feedings and muscle glycogen utilization during treadmill running in trained runners." Virtual Press, 1985. http://liblink.bsu.edu/uhtbin/catkey/438361.
Full textAbstract:
Six runners (V02 max=68.2 ± 3.4 ml/kg/min) were studied on three separate occasions during a 30 min treadmill run at 70% V02 max. On each occasion, the subjects ingested either 75g of glucose (trial G), fructose (trial F) or a sweetened placebo (trial C). No differences were observed between any of the trials for oxygen uptake, heart rate or perceived exertion. Serum glucose levels were elevated as a result of the glucose feeding (P<0.05) reaching peak levels at 30 min post-feeding. With the onset of exercise, glucose levels dropped to a low of 5.89 ± 0.99 mmol/l at 15 min of exercise in trial G. Serum glucose concentrations in trials F and C averaged 6.21 ± 0.31 mmol/l and 5.95 ± 0.23 mmol/l over all the time points, respectively, and were not different (p>0.05). Muscle glycogen utilization in the first 15 min of exercise was similar in trial C (18.8 ± 1.9 mmol/kg), trial F (16.3 ± 4.1 mmol/kg) and trial G (18.8 ± 9.1 mmol/kg), and total glycogen use was also similar in trial C (20.7 ± 5.3 mmol/kg), trial F (35.4 ±6.3 mmol/kg) and trial G (25.6 ± mmol/kg). These data suggest that pre-exercise feedings of fructose or glucose do not affect the rate of muscle glycogen utilization during 30 min of treadmill running in well-trained runners.
28
Davis, Jacqueline A. "The hypertensive response to repeated days of heat-exercise exposure." Virtual Press, 1989. http://liblink.bsu.edu/uhtbin/catkey/562777.
Full textAbstract:
The physiological responses of hypertensive subjects to a single bout of exercise in a hot environment have been investigated. It was the purpose of this study to compare the effect of successive days of exercise in the heat on borderline hypertensive and normotensive individuals, with particular interest being paid to the positive relationship that exists between plasma volume and blood pressure. Eight hypertensive subjects (HT) and 8 normotensive controls (NT) performed a standardized work task, (walking for 60 minutes at 3.5 mph on a 5% grade), in dry heat, (40C, 257. RH), on 7 successive days. Working capacity and acclimatization were compared during two, 90 minute heat tolerance tests (HTT), one prior to, and the other following the acclimation period.Both groups demonstrated a similar degree of heat acclimation, as reflected in significantly lower HTT2 core temperatures, (P< 0.05), and heart rates, (p< 0.01). Plasma volume expansion over the 9 days was also equal for both groups (+77.), but appeared to have no effect on their resting or exercising blood pressures. No differences were observed in the ability of either group to complete the work task, although the HT group exercised at a significantly higher percentage of their maximal oxygen uptake, (p< 0.05), than the NTs.These results indicate that no abbreviation in working capacity is experienced by borderline HT'% during exercise in the heat as a consequence of their high blood pressure. The anticipated elevation in blood pressure as a result of an expansion i n plasma volume did not occur. Consequently, these individuals show the same positive acclimation to exercise in the heat as their NT counterparts.School of Physical Education
29
Jucht, Kathy Rae. "The influence of age on excess post-exercise oxygen consumption." Virtual Press, 1990. http://liblink.bsu.edu/uhtbin/catkey/722441.
Full textAbstract:
Oxygen consumption remains elevated above resting values for a variable period of time after exercise. Exercise intensity and duration, food intake, laboratory conditions, metabolic measurements, gender and age are all major factors affecting the duration and magnitude of excess post-exercise oxygen consumption (EPOC). In the present study, the influence of age on EPOC was studied in men of various fitness levels. Various metabolic measurements were collected for three distinct age groups, 18-25, 35-45, and 55-67 at rest and during exercise at 60% of maximal oxygen consumption until 200 ± 10 kilocalories were expended. Immediately after the exercise bout, subjects walked on the treadmill for one minute and then were seated until oxygen consumption returned to within .01 liters of the recorded resting values.Percent body fat, V02 max and exercise V02 were significantly different between age groups. The duration (23-25 minutes) and magnitude (7-11 kilocalories) of EPOC did not differ significantly between groups. However, heart rate and minute ventilation were significantly elevated above resting measurements when V02 reached resting values. In conclusion, the physiological differences associated with the aging process were not found to significantly affect the duration and magnitude of EPOC.School of Physical Education
30
Martin, David E. "The effect of heat stress on excess post exercise oxygen consumption." Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834623.
Full textAbstract:
While a great deal of research has been directed towards the phenomena of excess post exercise oxygen consumption (EPOC), the effect of thermal stress on EPOC is not well defined. To assess the effect of heat stress on EPOC, seven healthy, active subjects (4 female, 3 male; 23.9 ± 2.0 years of age) performed 4 trials: one control (quiet rest) and one exercise (45 minutes of cycling at 65% VO2max workload) trial in moderate (23° C, 50% humidity) and hot (35° C, 50% humidity) environments. Oxygen consumption (V02), heart rate (HR) and rectal temperature (RT) were assessed pre, during and post control or exercise. Subjects were monitored until post exercise VO2 had returned to within ±2% of baseline. EPOC was determined by subtracting baseline VO2 from total V02 during the post exercise period. During the first 15 minutes (acute) post exercise, a significant EPOC (p = 0.0019) was seen in both exercise conditions over both control conditions. During the slow phase (> 15 minutes post exercise to baseline), there was no significant difference between the hot control (HC), moderate exercise (ME), or hot exercise (HE) EPOC. Total time post exercise until baseline was achieved was 35, 44, and 51 minutes for HC, ME, and HE respectively. HR was significantly elevated in both exercise conditions. During the acute post exercise period, HR in HE was elevated above MC, ME and HC (p < 0.05). RT was elevated in both exercise conditions during and post exercise. The present data indicate that heat stress does not have a significant effect on the magnitude or duration of EPOC.School of Physical Education
31
Moreau, Kerrie L. "The effects of blood lactate concentration on perception of effort during exercise." Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1014847.
Full textAbstract:
Several studies have reported that rating of perceived exertion (RPE) covaries more with blood lactate concentration (BLC) than other measures of relative exercise intensity. If BLC is used as the intensity criterion, then RPE could be used as a valid tool for exercise prescription. However, few have shown the relationship between RPE and BLC across a variety of graded exercise tests (GXTs) and exercise training settings. The purpose of this study was to determine if differences exist in RPEs at matched BLC between two GXTs and steady state exercise in the field setting. Thirteen healthy males (25 ± 5.3 yrs) completed two maximal treadmill protocols (Bruce and Balke) and one steady state exercise trial on a treadmill at two intensities which lasted approximately 7 minutes each. The intensities (40% & 70% max heart rate reserve) were below and above their ventilatory threshold. RPEs were recorded during the last minute of each workload of the field trial (FT). Immediately following the end of each workload, blood samples were collected for BLC analysis. RPEs from the FT were compared with RPEs from the GXTs at matched BI-Cs using a repeated measures ANOVA across exercise trials. The results show that there were no significant differences in RPEs at a matched BLC of 1.5 mM between the FTand and the Bruce and Balke GXT at the lower intensity, with the RPEs being 9.6 ± 1.7, 9.8 ± 2.6, and 10.2 ± 2.4, respectively. However, at the higher intensity, RPEs at a matched BLC of 3.0 mM were significantly different, with the FT < Bruce < Balke (11.9 ± 1.9, 13.5 ± 2.2 and 15.2 ± 2.0, p < 0.05). These results suggest that the relationship between RPE and BLC established during a GXT may not be transferable to the exercise training setting at exercise intensities in the typical prescription range of 50-85%. Therefore, using RPE for exercise prescription may not be an effective method for regulating exercise intensity according to BLC.School of Physical Education
32
Kim, Junghoon. "The influence of force production and eccentric exercise on growth hormone." Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1048386.
Full textAbstract:
The main purpose of this study was to investigate the relationship between human growth hormone (hGH) and two separate components of resistance exercise. Eight non-weight-trained subjects (23.33 ± 0.3 yrs) performed three force production trials (FPT), at different concentric workloads, and an 120% eccentric exercise trial (EET) on the Cybex 6000. Blood samples (3 mls) were taken pre- and post-exercise and analyzed for lactate, creatine kinase (CK) and hGH. Electromyographic (EMG) activity of the quadriceps muscle was recorded during each trial. The mean peak torque produced during the FPTs increased as work intensity increased but was the highest in the EET. The data for total work showed a proportional relationship with the intensity of the three concentric work loads but not the 120% EET. EMG activity of vastus medialis (VM) and rectus femoris (RF) measured during EET was 26% less than RF of 50% and 15% less than VL of 70% in FPT, respectively. The highest hormonal response occurred following the 120% EET. The hormonal response following the FPTs was highest in the 90% FPT with the two lower work intensity trials (50 and 70%) showing no clear hormonal response. Although the hGH response was the highest in the 120% EET, the post-exercise lactic acid levels in EET were 24% less than that of the 90% FPT. Creatine kinase (CK) activity was significantly elevated 36 hours after the last bout of EET which suggests that the eccentric exercise resulted in muscle damage. The results from concentric trials showed that muscle force generation, EMG, and lactic acid of the three different concentric trials were well correlated to the pattern of hGH secretion. However, only peak torque was consistent with the hGH response of the EET. The highest peak torque and hGH levels were achieved with eccentric exercise. The highest levels of fatigue, as a result of the combination of longer exercise time and overloading of the muscle during EET, may explain the higher hGH output. The muscle damage caused by the eccentric trial was enough to induce delayed onset of muscle soreness and may be the stimulus for the higher hGH output. The hGH response may facilitate repair of the muscular damage induced by eccentric exercise by promoting protein synthesis.School of Physical Education
33
Lyons, M. "The effects of prior moderate and intense exercise on sports-related performance." Thesis, Coventry University, 2011. http://curve.coventry.ac.uk/open/items/5cf904e2-2558-40b8-b13d-54c22d10e6e8/1.
Full textAbstract:
The main aim of this research was to develop a greater understanding of the effects of prior moderate and intense exercise on sports-related performance. The research developed through five related studies that examined the effects of exercise on key aspects of sports performance. Each study was conducted in appropriate field-based settings, using protocols that have relevance to the chosen sports and performance tasks that display ecological validity. Three intensities were examined across each of the five studies; rest, moderate and intense exercise. The preliminary study explored the effects of moderate and intense exercise on soccer passing performance in collegiate level players (n = 20). Repeated measures ANOVA revealed a significant (p = 0.010) effect of prior exercise on passing performance. Following on from this investigation, the effects of prior exercise on basketball passing performance in expert (n = 10) and non-expert players (n = 10) was examined. A 3 x 2 mixed ANOVA revealed a highly significant exercise intensity effect (p 0.001) as well as a highly significant exercise intensity by level of expertise interaction (p = 0.010). No between-group differences were observed however. This study nevertheless revealed that the expert players maintain a better level of performance compared to non-expert players following moderate and high-intensity exercise conditions. The third study explored the effects of moderate and intense exercise on coincidence-anticipation timing in expert (n = 11) and non-expert (n = 9) Gaelic games players. The 3 x 2 mixed ANOVA revealed no overall exercise intensity effect (p > 0.05) but there was a significant exercise intensity by level of expertise interaction (p = 0.031). Highly significant between-group differences (p < 0.001) were found, with the expert players maintaining a higher level of anticipation following moderate and intense exercise conditions. Study four comprised a small-scale study (n = 12) examining the effects of moderate and intense exercise on attention using the Stroop Colour-Word Test. Repeated measures ANOVA revealed a significant (p = 0.030) effect of prior exercise on attention. This study identified that attention following moderate-intensity exercise is equivalent to that at rest. However, following intense exercise attention deteriorates to a level below that at rest. The final study examined the effects of exercise intensity on groundstroke accuracy in expert (n = 13) and non-expert (n = 17) tennis players and comprised the most ecologically valid design. A range of 3 x 2 mixed ANOVAs were conducted revealing highly significant (p < .001) main effects for exercise intensity as well as highly significant (p = 0.003) between-group effects. No exercise intensity by level of expertise interaction was found however. In general, the findings suggest that performance following moderate-intensity exercise is equivalent to that at rest. However, significant decrements in key aspects of sports-related performance were observed following intense exercise. The findings of this research indicate that the theories of arousal cannot by themselves account for the outcomes of this work and the relationship between exercise and arousal needs to be explored further. Future research is imperative employing ecologically valid protocols and sport-specific performance tasks. The ensuing results in this case will have much more application and relevance to trainers, coaches and players.
34
Ainslie, Philip N. "The prolonged exercise of hill walking : physiological, metabolic and ergonomic aspects." Thesis, Liverpool John Moores University, 2002. http://researchonline.ljmu.ac.uk/4995/.
Full text
35
Robergs, Robert A. "Muscle glycogenolysis during weight-resistance exercise." Virtual Press, 1990. http://liblink.bsu.edu/uhtbin/catkey/720314.
Full textAbstract:
Skeletal muscle glycogenolysis was investigated in eight subjects during both high (HI) (70% 1 RM) and low (LO) intensity (35% 1 RM) leg extension weight-resistance exercise. Total force application to the machine lever arm was determined and equated between trials via a strain gauge and computer interfaced system. After the sixth set, muscle glycogen degradation was similar in the HI and LO trials (46.9 ± 6.6 and 46.6 ± 6.0 mmol•kg-1 wet wt, respectively), with the LO trial characterized by almost double the repetitions (6.0 and 12.7 ± 1.1) and half the peak concentric torque per repetition (24.2 ± 1.0 and 12.4 ± 0.5). After the sixth set, muscle lactate accumulation was also similar (13.8 ± 0.7 and 16.7 ± 4.2 mmol•kg-1 wet wt for HI and LO trials, respectively). After two hours of passive recovery with no feedings, muscle glycogen storage during the HI and LO trials was 22.2 (±6.8) and 14.2 (±2.5) mmol•kg-1 wet wt, respectively These values represented glycogen synthesis rates of 11.1 (±3.4) and 7.1 (±1.3) mmol•kg-1 •hr-1 , and occurred without significant increases in blood glucose relative to resting concentrations. Optical absorbance measurement of PAS stained muscle sections revealed no differences in the glycogen content of fast (FT) and slow twitch (ST) fibers between trials. When data from each trial were combined, declines in absorbance were larger in FT than ST fibers after the sixth set (0.356 ± 0.048) than in slow twitch fibers (0.222 ± 0.039, p < 0.05). The increase in absorbanceduring the two hour recovery was also larger in FT than ST fibers (0.119 ± 0.024 and 0.055 ± 0.024, p < 0.05). When total force application was constant, muscle glycogenolysis was the same regardless of the intensity of resistance exercise. Glycogenolysis was greater in fast twitch fibers, as was glycogen storage during the immediate post-exercise recovery. The relatively high rate of glycogen synthesis after exercise may be evidence of glycogenesis from intramuscular metabolites.Human Performance Laboratory
36
Vaile, Joanna. "Effect of hydrotherapy on recovery of muscle-damage and exercise-induced fatigue." University of Western Australia. School of Sport Science, Exercise and Health, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0221.
Full textAbstract:
Achieving adequate and appropriate recovery from exercise is essential in ensuring optimal performance during repeated bouts of exercise. The use of various recovery interventions has become popular in an attempt to enhance subsequent performance and accelerate post-exercise recovery. The application of various post-exercise hydrotherapy interventions has become increasingly popular, however, the majority of current recovery practices appear to be based largely on anecdotal evidence as opposed to rigorous scientific research or evidence based findings. Physiologically, various hydrotherapy protocols have been shown to affect the body via fluid shifts (interstitial to intravascular space), changes in blood flow and cardiovascular function, and reductions in oedema. The possible psychological effects of water immersion must also be considered, with athletes commonly reporting reduced sensations of fatigue and soreness following immersion. Current literature suggests both hydrostatic pressure and water temperature to be important factors influencing the success of hydrotherapy. The overall aim of the present thesis was to enhance current knowledge and understanding with regards to the physiological and performance effects of various forms of hydrotherapy, used as a post-exercise recovery intervention. Initially, four cold water immersion interventions were compared to active recovery, performed between two bouts of high intensity cycling in hot environmental conditions. Effectiveness of recovery was determined via performance in a subsequent exercise bout; in addition, core body temperature, lactate, and heart rate were recorded. The remaining studies were designed to investigate the effects of cold water immersion, hot water immersion, contrast water therapy, and passive recovery 4 (control) following exercise-induced fatigue and exercise-induced muscle damage. Rate of recovery was assessed through changes in performance, core body temperature, thigh girths, blood markers, and perceived exertion/soreness. The results of the combined studies indicate cold water immersion to be more effective than active recovery when performed immediately post-exercise between two bouts of high intensity cycling in hot environmental conditions. Additionally, both cold water immersion and contrast water therapy were effective in aiding recovery from exercise-induced fatigue and exercise-induced muscle damage. Performance variables indicated an improved maintenance or return of performance following these recovery protocols. The present studies have provided additional information to the limited knowledge base regarding the effect of post-exercise hydrotherapy interventions, specifically, the effect of such interventions on subsequent athletic performance. In conclusion, cold water immersion and contrast water therapy appear to be superior to hot water immersion, active recovery, and passive recovery following fatiguing and muscle damaging exercise. Functional and physiological recovery was enhanced following the use of these two recovery protocols.
37
Diotti, Kristin A. "Recovery metabolism following exercise above and below the anaerobic threshold." Virtual Press, 2003. http://liblink.bsu.edu/uhtbin/catkey/1273263.
Full textAbstract:
This study determined the effects of exercising above (LATabove) and below(LATbelow) the lactate threshold, upon excess post-exercise oxygen consumption (EPOC) magnitude and duration among average fit females. Thirteen females underwent testing over a nine-day period (5 visits). Resting metabolic rate (RMR) was assessed over two days. A ramp cycle test determined peak V02 and LAT. Blood samples, ventilatory, and heart rate measurements were recorded during rest, exercise, and recovery. On separatedays, volunteers exercised 10% LATabove and LATbelow expending 300 kcals. Afterwards,heart rate, RER, and V02 were measured until within ± 5% of the baseline RMR. EPOC duration was significantly greater for LATabove (61.49 + 8.73 min) than LATbelow (30.72 + 4.81 min). EPOC magnitude was also significantly greater LATabove (24.29 + 3.67 kcals) than LATbelow (13.28 ± 2.10 kcals). This study demonstrated exercising at LATabove adds an additional energy cost component to the recovery dynamics.School of Physical Education
38
Van, Stavel Rosemary. "Effects of exercise on stress : a meta-analysis." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30159.
Full textAbstract:
Physical exercise is frequently prescribed by clinicians and researchers as an effective stress reduction technique. There has been some research to support this assertion, however the research has been varied in its methodological rigor. The design problems, variations in exercise programs, and the use of a wide range of psychological measures have made results difficult to interpret. Additionally, the psychological benefits and underlying change processes have not been clearly delineated. The purpose of this study was to conduct a meta-analysis of the research in this area in an attempt to answer specific questions regarding the role of exercise in stress reduction. This meta-analytic approach was
chosen because it permits the quantitative integration of findings of several studies and consideration of the variables that may influence the variance in study outcomes. The effectiveness of exercise as a treatment for stress, the type of exercise that was most beneficial, and the type of individual who gained the most from the exercise intervention was examined.
The 61 effect sizes, which were calculated from 24 studies included in the meta-analysis, were coded along with other variables considered important. Study components such as design type, stress level, type of exercise program, program length, frequency of exercise sessions, attrition rate, psychological measure, composition of sample, gender, and
study type were coded as independent variables. Effect size
was the dependent variable. Analysis of variance revealed that
exercise was an effective stress reducer, stressed people
gained a greater stress reduction effect than minimally
stressed people, and there were no differences between trait
and state anxiety reduction from pre- to post-exercise
program. In addition, a one-way ANOVA indicated that there was
a significant difference between program lengths. Examination
of the means revealed that an 8- to 12-week program was most
effective in reducing stress. Although there was a greater effect size for unpublished studies than published studies, the pattern of change for each study type was similar.
The significance of these results and recommendations for future studies are discussed.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
39
Hogan, Kyla B. "The hemostatic responses to exercise in hot and cold temperatures." Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1398717.
Full textAbstract:
Purpose: The impact of temperature on the coagulative response to exercise has not been well described. The purpose of this study was to assess the response of plasma thrombin-antithrombin (TAT) to exercise during exposure to both hot and cold temperatures, and to compare those responses to exercise under normal, temperate conditions. Methods: Fifteen healthy male subjects (25.3 + 4.3 years) volunteered to participate in this study. Subjects completed maximal cycle ergometer exercise tests in three different temperatures (20°C, 5° or 8° C, and 30°C) in an environmental chamber. All tests were conducted in random order and separated by at least seven days. Blood samples were obtained before and immediately after exercise and analyzed by Elisa to determine plasma concentrations of thrombin-antithrombin complex (TAT). Results: Subjects demonstrated significantly elevated plasma levels of TAT in all three temperatures immediately after exercise (normal =1.04 ± 0.44 ng/ml, cold =1.34 ± 0.79 ng/ml, hot =1.18 + 0.95 ng/ml) when compared to baseline measures (normal = 0.45 ± 0.26 ng/ml, cold = 0.88 + 0.57 ng/ml, hot = 0.64 + g/ml). Subjects also showed significant elevations in TAT concentrations both before and after exercise in the cold temperature when compared with the normal temperature. There was no significant difference between the hot and normal temperatures. Conclusion: An individual's coagulation potential is increased following maximal physical exertion and may be further increased by exposure to colder temperature. Key Words: coagulation, physical exertion, temperature, thrombosis.School of Physical Education, Sport, and Exercise Science
40
Lombard, Wesley Ross. "The effects of booster breaks during a sedentary night shift on physiological, psychomotor, psycho-physiological, and cognitive performance over a 3 night shift habituation phase." Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1005194.
Full textAbstract:
Despite extensive research into shift work, workers working under rotating shift conditions are still plagued by the effects of the desynchronisation resulting from working against their natural circadian rhythms. Additionally, modern industries are shifting towards tasks requiring greater cognitive demand with less manual labour incorporated into the tasks. Research into operator based tasks, and hence those of a sedentary cognitive base both during day and night shifts, has been focusing on the effectiveness of the standard rest/break schedule. Research indicating that the standard rest break schedule is often ineffective in eliminating operator discomfort and performance deterioration, with these affects argued to be more pronounced during a night shift schedule. Therefore current research set out to investigate alternative rest break schedules, incorporating a short bout of physical activity and stretching exercises which are proposed to enhance performance and subjective mood, while eliminating operator discomfort for sedentary based cognitive tasks. Three conditions were tested during a three day habituation shift cycle within a laboratory, incorporating two night shift groups (control and experimental) and a control day shift group. Twelve subjects made up each group, with the two night shift groups completing the shift schedule together. The control groups followed a typical 8 hour shift schedule while the experimental group performed a booster break (exercise and stretches) activity for 7.5 minutes every hour during the night shift schedule. Over the course of the shift, subjects completed a battery of six tests providing data on physiological measurements (heart rate and temperature), performance criteria (reaction time responses, memory and neurobiological) and subjective measures. Responses obtained for all the different parameters measured indicated a strong circadian influence for the majority of the variables, indicating the course of natural down regulation within physiological and performance criteria over the night shift. The booster break significantly improved reaction time performance, subjective ratings and resulted in a high sustainable activity level. Day shift comparisons indicating that within subjective measures and reaction time performance, the booster break resulted in similar responses to those of the day shift workers, while the control night shift groups reported significantly lowers results. Additionally, the booster break had positive influences during the circadian nadir, significantly improving parameters of performance and subjective ratings of sleepiness. The results of this study indicating which variables are strong predictors and indicators of the oscillations in performance and subjective ratings due to the circadian changes. The booster break interventions had positive effects on subjective ratings and reaction time performance, while also being argued to decrease the burden placed on the cardiac system as a result of increased sympathetic tone during the night shift, while additionally resulting in similar responses to those of day shift workers. Further studies are required, however, to provide conclusive evidence particularly within a working situation over a longer shift schedule.
41
Liang, Qingning, and 梁青寧. "Fibroblast growth factor 21 as a novel stress-responsive hormone during starvation and physical exercise." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208608.
Full textAbstract:
FGF21 is a stress-inducible hormone predominantly secreted from the liver. FGF21 acts as a downstream target gene of hepatic transcription factor PPARα that plays an obligatory role in mediating metabolic adaptation responses to prolonged fasting. However, the physiological roles of FGF21 in regulating glucose homeostasis during adaptive starvation responses and its underlying mechanisms remain unknown. Furthermore, FGF21 is induced by both acute and chronic exercise training in both rodents and human. The physiological significances and the underlying mechanisms for exercise-induced FGF21 production have not been explored so far.
Therefore, this study aims to investigate: 1) the mechanisms whereby FGF21 mediates the role of PPARα activation in modulating hepatic gluconeogenesis in response to prolonged fasting; 2) the physiological roles and mechanisms whereby FGF21 regulates exercise capacity and insulin sensitivity via its actions in the muscle during exercise; 3) the roles of FGF receptor-1 (FGFR1) and co-receptor βKlotho in mediating the metabolic effects of FGF21 during fasting and exercise.
Our results show thatFGF21 is induced by fasting in the liver and enters into the brain. Both FGF21knockout (KO) mice and PPARα KO mice exhibit severe hypoglycemia and defective hepatic gluconeogenesis during prolonged fasting, and these changes are accompanied by impaired activation of the hypothalamic-pituitary-adrenal (HPA)axis and blunted release of corticosterone from adrenalgland. Moreover, intracerebroventricular injection of recombinant FGF21 reverses fasting hypoglycemia and impairment in hepatic gluconeogenesis by restoring corticosterone production in both FGF21 KO and PPARα KO mice. These effects are abrogated by blockage of hypothalamic FGFR1or by pharmacological inhibition of ERK1/2in the hypothalamus. In addition,FGF21 acts directly on the hypothalamic neurons to activate FGFR1/βKlotho-ERK1/2-CREBsignaling pathway, thereby leading to the transcriptional activation of corticotropin-releasing hormone (CRH) and subsequent activation of the HPA axis.
FGF21 is also induced in the liver by exercise and FGF21 KO mice have decreased exercise capacity associated with lower mitochondrial content and thus lower insulin sensitivity compared to wildtype (WT)mice after exercise training.AMPK-PGC-1α signaling pathway is impaired in the muscle of FGF21 KO mice during exercise.FGF21treatmentincreasesmitochondrial content in myotubes, while inhibition of AMPK and knockdown of FGFR1, βKlotho and PGC-1αblocksthis effect. Moreover, FGF21 regulates genes and proteins involved in different steps of the autophagy process and these alterations are mediated by FGFR1/βKlotho-PGC-1α signaling cascade. Furthermore, replenishment of FGF21 reverses the reduced mitochondrial content and insulin sensitivity by restoring PGC-1α expression and subsequent increase in mitochondrial biogenesis and suppression of autophagy in the muscle of FGF21 KO mice.
In conclusion, our results identify FGF21 as a critical hormonal regulator of glucose homeostasis during prolonged fasting, by coupling hepatic PPARα activation to corticosterone release via stimulation of the HPA axis in the brain. Moreover, FGF21 acts in the muscle through two distinctive mechanism to maintain mitochondrial homeostasis during exercise training, involving both biogenesis of new mitochondria and decreased clearance of stressed mitochondria and thus to mediate the beneficial effects of exercise on lipid and glucose metabolism.published_or_final_version
Medicine
Doctoral
Doctor of Philosophy
42
Saldanha, Paulo. "Physiological monitoring during the bicycle Race Across America (RAAM) : a case study." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0033/MQ64188.pdf.
Full text
43
Bolster, Douglas R. "The effects of precooling on thermoregulation during subsequent exercise in the heat." Virtual Press, 1997. http://liblink.bsu.edu/uhtbin/catkey/1041903.
Full textAbstract:
The purpose of this study was to lower body core temperature prior to a simulated portion of a triathlon (swim-15min; bike-45min) and examine whether precooling could attenuate thermal strain and increase subjective exercise tolerance in the heat. Six endurance trained triathletes (mean ± SE, 28 ± 2 yr, 8.2 ± 1.7 % body fat) completed two randomly-assigned trials, one week apart. The precooling trial (PC) involved lowering body core temperature (-0.5°C) in water prior to swimming and cycling. The control trial (CON) was identical except no precooling was performed. Water temperature and environmental conditions were maintained at -25.6°C and -26.6°C/60% RH respectively, throughout all testing. Mean time to precool was 31:37 ± 8:03 and average time to reach baseline temperature during cycling was 9:35 ± 7:60. Oxygen consumption (VO2), heart rate (HR), rate of perceived exertion (RPE), thermal sensation (TS), and skin (Tsk) and core (Ta) temperatures were recorded following the swim segment and throughout cycling. No significant differences in mean body (TO or Tsk were noted between PC and CON, but a significant difference (P<0.05) in T, between treatments was noted through the early phases of cycling. No significant differences were reported in HR, V02, RPE, TS or sweat rate (SR) between treatments. Body heat storage (S) was negative following swimming in both PC (92 ± 6 W/m2) and CON (66 ± 9 W/m2). A greater increase in S occurred in PC (109 ± 6 W/m2) vs. CON (79 ±4 W/m2) during cycling (P<0.05) . Precooling attenuated the rise in T,, but this effect was transient. Based on the results from this study, precooling is not recommended prior to endurance exercise in the heat.School of Physical Education
44
Duncan, Glen E. "Physiological and perceptual responses to graded treadmill and cycle exercise in male children." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/902482.
Full textAbstract:
The assessment of ventilatory threshold (Tvent) and maximal oxygen consumption (VO2max) are routine laboratory procedures, yet there are few studies that have directly compared these measurements during different modes of exercise in children. Therefore, the purpose of this study was to compare the physiological and perceptual responses at Tvent and V02max during treadmill and cycle ergometry in prepubertal male children. Ten subjects (M ± SD, 10.2 + 1.3 yrs.) performed a graded exercise test to maximal effort on a treadmill and a cycle ergometer. The order of testing was counterbalanced. The treadmill protocol began at 3.0 mph and 2% grade and progressed in one minute stages. Similarly, the cycle protocol began at 30 watts (W) and progressed 10 W•min-1. For both protocols, each stage was designed to elicit an approximately 3.5 ml-kg-I- min-1 change in V02. In addition, finger stick blood samples were taken at 2, 3, and 5 minutes post exercise in order to assess maximal blood lactate (La) level. Mean V02max on the treadmill (58.2 ± 6.9 ml•kg-l.min-1) was greater (P < 0.05) as compared to the cycle (51.7 ± 7.7ml.kg-'•min-1), with the average difference and the cycle ergometer, V02max is a function of the testing modality. LiKewise, the V02 at Tvent is dependent on the mode of exercise, while Tvent expressed as a percentage of VO2max is independent of mode of exercise. The perceptual responses at Tvent appear to be linked to a percentage of V02max, rather than an absolute V02.School of Physical Education
45
Brien, Donald Michael. "The effect of induced alkalosis and acidosis on blood lactate appearance and performance capacity during simulated rowing." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26756.
Full textAbstract:
In order to test the effect of artificially induced alkalosis and acidosis on the appearance of blood lactate and work production, six well-trained oarsmen (age= 23.8 ±2.5 wt = 82.0 ±7.5kg.) were tested on three separate occasions after ingestion of 0.3 gm/kg body wt. NH4C1 (acidosis) , NaHC03 (alkalosis) or a placebo (control). Blood was taken from a forearm vein immediately prior to exercise for determination of pH and bicarbonate (HC03). One hour following the ingestion period, subjects rowed on a stationary ergometer at a pre-determined sub-maximal rate for 4 minutes, then underwent an immediate transition to a maximal effort for 2 minutes. Blood samples from an indwelling catheter placed in the cephalic vein were taken at rest and every 30 seconds throughout the 6 minute exercise test, and every 3 minutes during a 30 minute passive recovery period. Pre-exercise blood values demonstrated significant differences (p<0.01) in pH and HC03 in all three conditions. Work outputs were unchanged in the submaximal test and in the maximal test (p>0.05), although a trend toward decreased production was evident in the acidotic condition. Analysis of exercise blood samples using ANOVA with repeated measures revealed that the linear increase in blood lactate
concentration([BLA]) during control was significantly greater than acidosis (p<0.01), although [BLa] during alkalosis were consistently elevated above control there was no significant difference in the linear trend (p>0.05). During recovery, there was no significant difference in the rate of lactate disappearance amongst the three conditions. It was concluded that under this protocol artificial manipulation of the acid-base status of the blood does not significantly influence work production despite significantly reduced [BLa] during acidosis. The inability of these pH changes to alter exercise performance emphasizes the relative importance of the intracellular and the extracellular buffer systems in well trained athletes.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
46
Porter, David A. "The effect of oral coenzyme Q10 on the exercise tolerance of middle-aged, untrained men." Virtual Press, 1991. http://liblink.bsu.edu/uhtbin/catkey/776715.
Full text
47
Olbright, Lucinda Griffith. "THE EFFECTS OF ACUTE AEROBIC STRESS ON PREPREGNANT WOMEN OF CHILDBEARING AGE." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275245.
Full text
48
Esterhuyse, Aletta Maria. "The magnitude and duration of post exercise hypotension after land and water exercise." Thesis, Dissertations -- Sport science, 2009. http://hdl.handle.net/10019.1/1825.
Full textAbstract:
Thesis (M Sport Sc (Sport Science))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: It is well-known that acute and chronic aerobic and resistance exercise results in decreased blood pressure (BP) in hypertensive individuals. There is little evidence that water exercise has a similar effect on BP response. There is also no certainty regarding the magnitude and duration of post exercise hypotension (PEH) after either land or water-based exercise. Most studies were also performed under controlled laboratory conditions and very few characterised the PEH response under real life conditions. The current study endeavoured to examine the magnitude and duration of PEH after an acute session of water- and land-based exercise during free living conditions in persons with mild to moderate hypertension. Twenty-one men and women (aged 52 ± 10 years) volunteered for the study. All participants were pre-hypertensive or hypertensive. Participants completed a no exercise control session, a water exercise session and a combined aerobic and resistance land exercise session in random order. After all three sessions, participants underwent 24 hour monitoring using an Ergoscan ambulatory BP monitoring device. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and heart rate (HR) were monitored to determine changes from resting values after each session and to compare the PEH responses between land and water exercise. Overall, the land exercise treatment caused a 3.6 mmHg lower average SBP over 24 hours than the control treatment (P = 0.04). The average difference over 24 hours between the water and control treatments was 2.2 mmHg and between land and water exercise it was 1.5 mmHg (P > 0.05). During daytime, both land and water exercise resulted in significantly lower SBP (12.7 and 11.3 mmHg) compared to the control session (2.3 mmHg). The PEH response lasted for 24 hours after land exercise and nine hours after water exercise. There was no difference in the daytime DBP for the three treatments (P > 0.05). Although all three groups showed significant reductions during night time, both exercise treatments showed greater nocturnal falls in SBP, DBP and MAP than the control treatment.
AFRIKAANSE OPSOMMING: Dit is alombekend dat akute en chroniese aërobiese- en weerstandsoefening tot ‘n afname in bloeddruk (BD) lei in persone met hipertensie. Daar is egter min getuienis dat wateroefening dieselfde effek op die bloeddruk respons het. Daar is ook nie sekerheid oor die grootte en duur van post-oefening hipotensie na water- of landoefening nie. Die meeste studies is onder gekontrolleerde laboratorium omstandighede gedoen en min resultate is beskikbaar onder alledaagse lewensomstandighede. Die huidige studie het gepoog om die grootte en duur van die post-oefening hipotensie respons in persone met ligte tot matige hipertensie onder alledaagse omstandighede na ‘n akute sessie van water- en landgebaseerde oefening te ondersoek. Een-en-twintig mans en vrouens (ouderdom 52 ± 10 jaar) het ingewillig om aan die studie deel te neem. Alle deelnemers was hipertensief of pre-hipertensief. Alle deelnemers het ‘n kontrolesessie, ‘n wateroefeningsessie en ‘n gekombineerde aërobiese en weerstands landoefensessie, in lukrake volgorde, voltooi. Na elke sessie het die deelnemers 24 uur bloeddrukmonitering met ‘n Ergoscan wandelende bloeddruk monitor ondergaan. Sistoliese bloeddruk (SBD), diastoliese bloeddruk (DBD), gemiddelde arteriële bloeddruk en harttempo (HT) is gemonitor om die veranderinge vanaf rustende waardes na elke sessie te bepaal en om die hipotensiewe respons na land- en wateroefening te vergelyk. Landoefening het ‘n 3.6 mmHg laer gemiddelde SBD oor 24 uur tot gevolg gehad in vergelyking met die kontrolesessie (P = 0.04). Die gemiddelde verskil oor 24 uur tussen die water- en kontrolesessies was 2.2 mmHg en 1.5 mmHg tussen die land en water oefensessies (P > 0.05). Gedurende die dag het beide die land- and wateroefening gelei tot beduidende laer SBD (12.7 en 11.3 mmHg) in vergelyking met die kontrolesessie (2.3 mmHg). Die post-oefening hipotensie het 24 uur geduur na die landoefening en nege uur na die wateroefening. Daar was geen verskil in DBD gedurende die dag tussen die drie groepe nie (P > 0.05).
49
Hickey, Matthew Sean. "Hormonal and metabolic responses to opioid antagonism during dynamic exercise : influence of exercise intensity." Virtual Press, 1993. http://liblink.bsu.edu/uhtbin/catkey/862279.
Full textAbstract:
In an attempt to investigate the role of the endogenous opioid peptides in substrate utilization and hormonal responses to exercise, eight trained cyclists completed two exercise trials at each of two distinct intensity/duration combinations. Briefly, cyclists completed two trials at 70% VO2max for 90 minutes and two trials at 90% VO2max until exhaustion. Trials were conducted following the administration of the opiate antagonist naloxone (NAL) (0.1 mg-kg-1 bolus + 0.1 mg-kg-1-·hr-1) or volume matched saline (SAL). Serum glucose was maintained at significantly higher levels at 60 and 90 minutes of exercise in 70% NAL vs 70% SAL. Serum glucose was significantly higher at all points during exercise and at 30 and 60 minutes of recovery in 90% NAL vs 90% SAL. Serum insulin was not altered by naloxone administration at either 70% or 90% trials. Serum Cpeptide was significantly higher at 60 and 90 minutes in 70%-NAL vs 70% SAL, and was significantly lower during exercise in 90%-NAL vs 90% SAL. Plasma glucagon was not different during exercise in the 70% trials, but was significantly higher during exercise in 90%-NAL vs 90%-SAL. The glucagon:insulin molar ration was not significantly altered by naloxone administration in any trial. Rating of peceived exertion was significantly higher during exercise in 70%-NAL, but was not different during exercise in the 90% trials. However, time to exhaustion was significantly (18%) reduced in 90%-NAL vs 90%-SAL. No systematic differences were observed in the cardiorespiratory responses to exercise at either intensity, although pulmonary ventilation was modestly (7%) elevated in 90%-NAL. Thus, opiate antagonism prevents the decline in serum glucose seen in prolonged exercise without altering substrate oxidation, and with minimal influence on the pancreatic hormone response. In contrast, opiate antagonism potentiates the hyperglycemic response to high intensity exercise at least in part by altering pancreatic hormone responses which may contribute to the hyperglycemia.School of Physical Education
50
Wall, Bradley A. "Exercise as medicine : reversing treatment toxicities in prostate cancer patients." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/691.
Full textAbstract:
A common treatment for prostate cancer, which is the most common form of cancer after skin cancer in Australian males, is androgen deprivation therapy (ADT). However, ADT is associated with an array of adverse effects including reduced bone and lean mass, loss of muscle strength, negative change in lipid profile, and increased risk of cardiovascular disease (CVD) as well as diabetes, all of which can compromise physical function and quality of life. Physical exercise has been suggested as a key lifestyle intervention for this group of cancer patients as it has enormous potential to limit and even reverse the effects of such treatment toxicities. This thesis is comprised of a review of the literature and three experimental chapters examining the effects of androgen deprivation therapy (ADT) and the role of exercise in ADT treated prostate cancer patients. The review of literature provides a background to cancer, in particular prostate cancer and the commonly reported side effects of treatment. The review identified gaps in the literature that highlighted the need for well controlled and longer term experimental studies to: 1) investigate the impact of androgen deprivation therapy duration on cardiovascular and metabolic outcomes, and 2) investigate the effects of a long term exercise intervention in reversing cardiovascular risk factors and unfavourable alterations in the metabolic profile.
Study 1 examined the feasibility and safety of a maximal treadmill exercise test in ADT treated prostate cancer patients as this was a key assessment of physiological response to the exercise intervention. One hundred and twelve prostate cancer patients undergoing ADT took part in a physician supervised multistage maximal stress test (Bruce protocol). Of these men, 85% were able to meet the criteria for the attainment of VO2max whilst three positive tests (3.2%) were observed. The three participants who recorded a positive stress test were sent for further examination and subsequently cleared of any serious issues. Apart from the relatively low VO2max (10-15th percentile), compared to healthy age matched controls, the cardiovascular response to exercise is similar in this cancer population. Maximal exercise testing in this population was demonstrated to be feasible and safe providing a direct assessment of VO2max whilst treatment duration did not appear to influence the cardiovascular responses to exercise.
Study 2 was a cross-sectional design comparing chronic versus acute ADT treated patients to examine if therapy time exposure leads to additional risk factors for CVD and metabolic toxicities in prostate cancer patients. One hundred and seven men undergoing ADT for treatment of prostate cancer were stratified into two groups, either acute (months) or chronic (>3 months) exposure. Chronic ADT exposure was associated with a 17% reduction maximal aerobic capacity (-0.4 L.min-1) and an 8% reduction in resting metabolic rate (-147 kcal/24hr). The chronically exposed group also exhibited 8-22% lower maximal strength values (chest press -5.9kg, seated row -3.9kg, leg press -27.5kg and leg extension -12.2 kg) and a corresponding decrement in physical function variables ranging from 9-16% (400m walk +24.9s, chair rise +2.0s, and stair climb +0.7s). Whilst not significant, there was also a trend towards a decrease in lean mass of 3.5% (-2.1kg) and an increase in fat mass of 6.5% (1.5kg) in the chronically suppressed group. ADT exposure did in fact have a negative effect on CVD risk factors as well as physical function outcomes. Whilst the exact mechanisms remain unclear as to why these cardiovascular alterations and physical function variables are further declining as treatment time progresses, it is possible that factors other than those assessed in this study, such as reduced physical activity levels, may have influenced the results.
Study 3 utilised a randomized controlled trial (RCT) study design to examine the long-term effects (6 months) of a combined aerobic and resistance training intervention in reducing or stabilizing CVD and diabetes risk factors in men receiving ADT. Participants were randomly allocated to either an exercise (EX) group (n= 50) or a control (CON) group (n= 48). The combined aerobic and resistance training program consisted of twice weekly clinic based sessions at which the participants completed 20mins of aerobic activity (70- 90% maximal intensity) and 6 resistance based exercises targeting the major upper and lower body muscle groups. In addition, participants were prescribed a home based training program consisting of 110 minutes of aerobic activity. The control group were instructed to adhere to their usual lifestyle and care routine. Body composition [lean mass 1.1% (+0.8kg), fat mass -4.2% (-1.1kg) & body fat -3.8% (-1.1kg], muscular strength [chest press 9.6% (+3.6kg), seated row 7% (+6.0kg), leg press 14.8% (+20kg) & leg extension 19.4% (+10.2kg)], muscular endurance [chest press 49.4% (+5.0 reps) & leg 49.9% (+7.7 reps)] and 400m walk [-4.8% (-13s)] significantly improved (p
This research has demonstrated that: 1) maximal cardiorespiratory exercise testing is safe and feasible in this population, 2) prolonged exposure to androgen deprivation therapy (>3 months) has a negative impact on a number of cardiovascular, metabolic and physical function outcomes, and 3) a combined aerobic and resistance training program can be safely undertaken in men undergoing ADT and results in an array of benefits for cardiovascular and metabolic outcomes as well physical function. As a result of these findings, patients prescribed ADT for the treatment of prostate cancer should be appropriately counselled as to the negative side effects commonly associated with this form of treatment and be made aware of the safety and beneficial effects an appropriately administered exercise intervention can have on reversing these adverse alterations occurring throughout the course of treatment. Further, these specifically designed exercise interventions should be commenced as soon as practically possible post prostate cancer diagnosis and continue for the course of treatment and ideally beyond.