Dissertations / Theses on the topic 'Distance runners'

Running economy is well established as a primary determinant of endurance running performance. However, there is a lack of clarity about the preferred measurement of running economy, its primary limiting factors and the most robust methods enhance running economy in highly trained athletes. Therefore, this thesis investigated the running economy of highly trained runners, exploring the reliability and validity of measures of running economy to deduce its most appropriate quantification, the application of innovative methods to enhance our understanding of an athlete s running economy, and a novel training method to enhance running economy. Chapter 3 revealed that energy cost and oxygen cost were shown to provide similarly high levels of reliability (typical error of measurement ~3%) for highly trained endurance runners when assessed using a short-duration incremental submaximal exercise protocol. In chapter 4, the analysis of a large cohort of highly trained endurance runners revealed that energy cost increased in a stepwise manner with increments in running speed (P<0.001), however oxygen cost remained consistent (P=0.54) across running speed; indicating that oxygen cost might not be an appropriate measure of running economy. Chapter 5 demonstrated that the inter-individual variation in the magnitude of changes in energy cost between different gradients (i.e. from flat running to uphill/downhill running) in highly trained runners was low. However, a disparity between the energy saving of running on a -5% gradient (-17%) and the additional energy cost of running on a +5% gradient (+32%) was evident. The cross-sectional and longitudinal analysis of a large cohort of highly trained runners in chapter 6 revealed a small (r=0.25) and moderate (r=0.35) association between energy cost and maximal oxygen uptake, respectively. Finally, chapter 7 demonstrated that eight weeks of supplementary downhill run training at vLTP in existing training programmes does not enhance running economy in already well trained runners (1.22 vs 1.20 kcal kg-1 km-1; P=0.41), despite a significant increase (+2.4%) in the velocity at lactate turnpoint. In conclusion, this thesis demonstrates that energy cost, expressed as kcal kg-1 km-1, provides a reliable and valid method to quantify running economy in trained distance runners. However, further investigation is required to identify robust training methods to enhance running economy in this already highly trained population.

Adolescent growth provides a unique opportunity for the growing body to adapt to external stimuli. A positive association between site-specific mechanical loading and increases in regional bone mineral content (BMC) during adolescence is established. Mechanical loads associated with middle-distance running expose the skeleton to a combination of compressive ground reaction forces and muscular contraction. Previous studies concerning musculoskeletal health in active adolescents are largely limited to planar, two-dimensional measures of bone mineral status, using Dual X-ray Absorptiometry (DXA). Intrinsic bone material properties are accurately measured using DXA. However, the interaction between bone material and structural properties that reflects the mechanical integrity of bone require a combination of imaging modalities. Magnetic Resonance Imaging (MRI) provides a three-dimensional geometric and biomechanical assessment of bone. When MRI is integrated with DXA technology, an effective non-invasive method of assessing in vivo bone strength is achieved. The impact of high training volumes on musculoskeletal development of male and female adolescent athletes engaged in repetitive, high magnitude mechanical loading has not been investigated. Specifically, differences in total body and regional bone mineral, bone and muscle geometry, bone biomechanical indices and bone strength at differentially-loaded skeletal sites have not been compared between adolescent middle-distance runners and age- and gender-matched non-athletic controls. Objectives: (i) to investigate the effects of intense sports participation involving mechanical loading patterns on bone mineral, bone and muscle geometry, biomechanical indices and estimated regional bone strength between elite adolescent male and female middle-distance runners and age- and gender-matched controls (ii) to examine factors predictive of total body BMC, distal tibial bone geometry, distal tibial bone strength, and Hip Strength Analysis (HSA)- derived indicators of bone strength at the femoral neck. Methods: Four groups of 20 adolescents were comprised of male (mean (SD) age 16.8 ± 0.6 yr, physical activity 14.1 ± 5.7 hr.wk-1) and female (age 16 ± 1.7 yr, physical activity 8.9 ± 2.1 hr.wk-1) middle-distance runners, and male (16.4 ± 0.7 yr, physical activity 2.2 ± 0.7 hr.wk-1) and female (age 16 ± 1.8 yr, physical activity 2.0 ± 0.07 hr.wk-1) controls. Total body and regional BMC were calculated using DXA. Distal tibial bone and muscle cross-sectional areas (CSA) were assessed using MRI. To calculate distal tibial bone strength index (BSI), a region of interest representing 10% of the mid distal tibia was analysed for DXA-derived bone mineral and was combined with bone geometry and biomechanical properties from MRI assessments. Calculations for femoral neck strength were acquired from DXA-derived HSA software. Results: No differences were found between male athletes and controls for unadjusted BMC at total body or regional sites. After covarying for fat mass (kg), male athletes displayed greater BMC at the lumbar spine (p = 0.001), dominant proximal femur (p = 0.001) and dominant leg (p = 0.03) than male controls. No differences were found in distal tibial bone geometry, bone strength at the distal tibia or HSA-derived indicators of bone strength at the femoral neck between male athletes and controls. Lean tissue mass and fat mass were the strongest predictors of total body BMC (R2 = 0.71), total muscle CSA explained 43.5% of variance in BSI at the distal tibia, and femur length and neck of femur CSA explained 33.4% of variance at the femoral neck. In females, athletes displayed greater unadjusted BMC at the proximal femur (+3.9 ±1.4 g, p = 0.01), dominant femoral neck (+0.5 ± 0.12 g, p = 0.01) and dominant tibia (+4.1 ± 2.1 g, p = 0.05) than female controls. After covarying for fat mass (kg), female athletes displayed greater (p = 0.001) total body, dominant proximal femur and dominant leg BMC than female controls. Female athletes also showed greater distal tibial cortical CSA (+30.9 ± 9.5 mm2, p = 0.003), total muscle (+240.2 ± 86.4 mm2, p = 0.03) and extensor muscle (+46.9 ±19.5 mm2, p = 0.02) CSA, smaller medullary cavity (-32.3 ± 14.7 mm2, p = 0.03) CSA and greater BSI at the distal tibia (+28037 ± 8214.7 g/cm3.mm4, p = 0.002) than female controls. Lean tissue mass and fat mass were the strongest predictors of total body BMC (R2 = 65), hours of physical weekly activity and total muscle CSA explained 58.3% of the variance of distal tibial BSI, and neck of femur CSA accounted for 64.6% of the variance in a marker of femoral neck HSA. Conclusion: High training loads are associated with positive musculoskeletal outcomes in adolescent middle-distance runners compared to non-athletic controls. Exposure to similar high training loads may advantage female adolescent athletes, more than male adolescent athletes compared with less active peers in bone strength at the distal tibia.

Thesis (Ph.D.)--Indiana University, School of Health, Physical Education and Recreation, 2007.
Source: Dissertation Abstracts International, Volume: 68-10, Section: A, page: 4239. Advisers: Robert Robergs; David Koceja. Title from dissertation home page (viewed May 19, 2008).

In the sport of track and field, sprinting and distance running represent two major categories of athletes. Sprinting is associated with power and speed, whereas distance running focuses on the economy of movement. With distance running there are elements of sprint technique that overlap. With distance events, there comes a time near the end of the race where economy gives way to speed. If the distance runners knew how to alter their technique in a way to become more sprint-like, this process could possibly be more successful. PURPOSE: This study compared the differences in technique between sprinters and distance runners while running at equal and maximal speeds. METHODS: Subjects for the study consisted of 10 Division I collegiate distance runners, 10 Division I collegiate sprinters, and 10 healthy non-runners. The subjects performed two tests, with each consisting of a 60 meter run completed on the track. Test 1 was run at a pace of 5.81 m/s (4:37 min/mile), while Test 2 was completed at maximal speed. Video footage of each trial was collected at 180 Hz, monitoring hip, knee, thigh, and shank positions, as well as stride length, and contact time. RESULTS: Significant differences (p < .05) between the sprint and distance groups at maximal speed were found in the following areas: speed, minimum hip angle, knee extension at toe-off, stride length, contact time, and the position of the recovery knee at touchdown. Sprinters and distance runners exhibited a significantly lower minimum knee angle than those in the control group. Significant differences between the sprint and control group existed at the minimum hip angle, speed, stride length, contact time, and the position of the recovery knee at touchdown. Regarding the paced trial, the sprinters and distance runners showed significant difference concerning the minimum hip angle, center of mass at touchdown, and recovery knee at touchdown. Sprinters differed significantly from the control group in contact time, the center of mass at touchdown and the position of the recovery knee at touchdown. CONCLUSION: As distance runners attempt to sprint, the desired adaptations do not necessarily occur. The development of economical distance form is a fairly natural process that occurs with the miles of training. Sprinting, however, is a separate, learned technique that often requires specific feedback. When attempting maximal speed, distance runners may benefit by focusing on one characteristic of technique. If knee extension at toe-off could be trained to become more sprint-like, the other characteristics unique to sprinters may follow.

Master of Science
Department of Hospitality Management and Dietetics
Betsy Barrett
The topic of athlete nutrition has been discussed amongst competitors, coaches, and nutrition professionals since the dawn of the Modern Olympic Movement in 1896 and has led to many strategies to help athletes compete at a higher level. Endurance athletes have been studied around the world. However, studies conducted with elite distance runners at altitude have focused mainly on male athletes in Kenya or Ethiopia. Despite the efforts of researchers over the years in the area of athlete nutrition there has been little research that specifically focuses on elite female distance runners and little evidence is available about the dietary habits and beliefs of these athletes. Therefore, the purpose of this study was to identify the macronutrient and fluid intakes of female distance runners and to determine if current fad diets and specific athletic events impact their eating habits. Seven female elite distance runners (six of European and one of Asian descent) training at altitude completed the study. Their specific events ranged from the 5-K to ultra-marathon. The athletes entered their food, fluid and physical activity for six weeks and submitted a report weekly to the researcher. The data was entered by the researcher into myfitnesspal.com which tabulated the data. The results recorded into Excel spreadsheets for each athlete. At the end of the six weeks, all data was compiled to get a total intake for each athlete and the group as a whole. Mean, minimums, maximums, and standard deviations were used for data analysis. At the end of the six weeks, a telephone interview was conducted with each athlete to determine their eating habits, attitudes towards food, how others impacted their eating and if they were following a fad diet and why. Results indicated that these athletes reported lower mean carbohydrate (51±19.4% of calories) and higher protein (19±6% of calories) intake than is recommended per the Joint Statement of the ADA, DC and ACSM (2009). Fat and fluid consumption were adequate, but overall calories taken in were a little lower than calories expended. The athletes avoided soy, high fructose corn syrup, artificial sweeteners, dairy, and fried foods and focused on eating more fruits and vegetables. Five of the seven athletes were following a gluten free diet because they felt it gave them a competitive edge, increased performance, and reduced GI distress. Based on the results of this study, coaches and athletes should focus on perceived exertion in workouts, macronutrient amounts and overall calories to ensure the athlete is able to compete at a high level.

The purpose of this study was to examine the changes in running economy of collegiate cross-country runners with 6 weeks of training on the PowerCranks ™ independent bicycle crank. Thirteen collegiate cross-country runners completed the study. Participants were asked to perform 6 weeks of training with either the PowerCranks™ device or the standard cranks (control group). Participants trained 3 days per week with a 48-hour minimum rest time between training sessions. Pre- and post-running economy and V02 max test data were collected. Data were analyzed with SPSS version 19 using a paired-samples t test as well as an independent t test. The paired samples I-test results for the participants pre-training running economy in the PowerCranks™ group were 2.98 ± 0.60 Llmin to 3.08 ± 0.59 Llmin post training; p = 0.057, 1= -2.464. The control group for the PowerCranks™ results were 2.68 ± 0.51 Lfmin pre-training, with post training results of2.69 ± 0.57 L/min,p = 0.815, t = -.245. Results for pre-training V02 max were 4. 10 ± 0.72 Llmin to 4.17 ± 0.75 Lll11in post training; p = 0.230, [= -1.366 with the PowerCranks™ group. The control group [or V02 max. results wen: 3.83 ± 1.10 Llmin pre-training with post-training resulting as 3.92 ± 1.09 Llmin,p = .245, t = -1.287. The results of the independent t test also showed that there was no significant change in values for running economy (t = -.112, P = .913) or V02 max (/ = 1.569,p = .145) when PowerCranks™ and control groups were compared. It was concluded that within the limitations of this study, experienced collegiate numers who performed 6 weeks of cross training with the PowerCranks™ independent cycle crank displayed no significant difference in running economy or VOz max results post training.

When distance runners are recruited or walk-on to participate on their college track teams, they have two main goals in mind. They want to have a satisfying individual and team experience, and they have a desire to win and be the best. The outcomes of these goals are most directly influenced by their coach, who plans, develops, and implements the mental and physical aspects of the distance runnersâ overall training program. Wins and losses can be measured on the track, but distance runnersâ perceptions of satisfaction with their athletic experience are not often or easily assessed. Based on the advantages that satisfaction can offer student-athletes, this study was designed to achieve a dual purpose. The primary purpose of this study was to examine the relationship between collegiate distance runnersâ satisfaction and training protocols. The secondary purpose of this study was to determine the relationship between collegiate distance runnersâ training program satisfaction and performance. The participants included 130 NCAA distance runners from the six major Division I conferences. In order to assess satisfaction levels of training and instruction protocols and performance, the procedures required the distance runners to complete the 2010 Track Distance Athlete Satisfaction and Performance Questionnaire. The 2010 Track Distance Athlete Satisfaction and Performance Questionnaire was comprised of the following four sections: training (satisfaction), instruction (satisfaction), performance (satisfaction), and demographic information. The results were analyzed to determine the relationships between satisfaction and the training and instruction protocols and between overall training program satisfaction and performance, gender, and academic level. The results of this study indicated that NCAA Division I distance runners perceive their coachesâ overall training programs and training and instruction protocols as satisfying. Further research is needed to continue to fill the gap in the satisfaction and performance literature and to develop a comprehensive understanding of this complex relationship. Overall, this study found that distance runners who are satisfied with their training program tend to be confident in their training, motivated, trusting of the coach and his or her training program, and enjoy their college racing and training experience. Therefore, satisfaction also positively affects distance runner retention.
Ph. D.

Aim: The aim of this thesis was to contribute to a better understanding of heart rate during exercise with the aim of improving the precision with which heart rate can be used to measure intensity during running. Accordingly, heart rate responses were examined in long distance runners during different types of training and racing. The thesis also examined the effects of environmental and body temperature on heart rate during submaximal and maximal running. Study 1: Ten male provincial and national class road runners (VO₂max = 67.1 ± 3.8 mlO₂.kg⁻¹. min⁻¹) were recruited for the study. All the subjects completed questionnaires on their training history and recorded their training sessions in their diaries. The subjects wore heart rate monitors during training and racing. There was no convincing evidence that competitive runners who train at higher intensities have a better running performance. A poor relationship was found between %VO₂max and %HRmax. Finally, heart rate during races was higher compared to heart rates during training. The cause of the elevated heart rate during races was not clear. Study 2: The relationship between heart rate and running speed during competition was not well understood. Accordingly, an elite long distance male runner (25 years, VO₂max = 71 mlO₂.kg⁻¹. min⁻¹) was studied over a 5-month period during which time he participated in 9 races (5 km - 28 km). The subject wore a heart rate monitor which measured his heart rate throughout the race and his split running times each kilometre. The subject underwent a field test during which the heart rate/running speed relationship was determined under non-competitive conditions (r = 0.99). However, in the race situation there was no relationship between heart rate and running speed (r = 0.02). It was concluded that during competition there was no relationship between heart rate and running speed, whereas in a non-competitive situation heart rate was proportional to running intensity. Study 3: With a poor relationship found between heart rate and running speed during races in the previous study, other factors like environmental conditions and core temperature were hypothesised to have effects on heart rate. Accordingly, twelve highly trained distance runners were recruited for the study. Each subject ran on a treadmill (30 minutes at 70% peak treadmill running speed, followed by 8 km time trial) in different ambient temperatures (15°C, 25°C and 35°C) with humidity (60%) and wind speed (15 km.h⁻¹) kept constant. Heart rate, RPE and Tre were recorded every 5 minutes during the submaximal and the maximal trials. When subjects were exercising at 70% of peak treadmill running speed at 15°C, no cardiovascular drift was observed, at least for 30 minutes. However, during the same exercise test at 25 °C and 35°C there was a significant increase in heart rate. In the maximal exercise test the average heart rate was significantly higher during the trial at 35°C compared to the trials at 15° C and 25° C. It was concluded that heart rate can be used as an accurate measure of running intensity in cooler (15 ° C) ambient temperature. In summary, this thesis described the practical use of heart rate monitors during training and competition and at different temperatures. Data are provided which suggest that heart rate can accurately assess exercise intensity providing factors which affect the heart rate/running speed relationship are controlled.

Master of Science
School of Journalism and Mass Communications
Nancy Muturi
This study was an examination of the determinants of disordered eating development among female collegiate distance runners. More specifically, the study examined the impact of thinness-emphasizing and thinness-promoting messages disseminated by mass media and running-specific media, and how those messages affected disordered eating among a sample of female collegiate distance runners. It also examines current female collegiate distance runners’ attitudes toward disordered eating, subjective norms from referent individuals close to female collegiate distance runners regarding disordered eating, and female collegiate distance runners’ perceived behavioral control regarding disordered eating—which was divided into various internal and external control factors either inhibiting or facilitating disordered eating among them. The study was qualitative in nature and assumed a multi-method approach. It included an online, anonymous, self-administered questionnaire among 166 current NCAA Division I female distance runners; four small, confidential focus groups with current NCAA Division I female distance runners from four different teams; and 16 in-depth interviews with professional distance runners, dietitians, coaches, physicians, and sports psychologists. The study sought to answer four research questions—each based on an element of the study’s guiding theory, the theory of planned behavior (Ajzen, 1991). Overall, the study found media messages, attitudes, subjective norms, and various internal and external control factors all facilitated disordered eating among NCAA Division I female distance runners. Based upon these findings, the study offers recommendations for practitioners in the field of health communication, coaches, academic institutions with cross country and track teams, and female collegiate distance runners.

The sample included 29 healthy competitive male distance runners. Bilateral measurements were taken for selected variables of the talocalcaneal flexibility by means of a mechanical goniometer, and of the peak isokinetic knee strength on a Cybex II device. The frontal and horizontal plane motions of the lower limbs of the subjects were recorded by high speed filming and videotaping while they were running on a motor driven treadmill at their training pace under two conditions: with running shoes and barefoot. A detailed description of each runner's history was obtained and bilateral dominance characteristics were determined. Significant functional asymmetries were found for subtalar joint flexibility (eversion, inversion, and eversion/inversion ratio) and peak isokinetic knee strength (flexion, extension, total, and flexion/extension ratio). Significant kinematic asymmetries were revealed during the foot support phase in lower leg angle, rearfoot angle, mediolateral velocity of the foot, and in some temporal parameters. The two running conditions differed significantly only for the pretouchdown phase of support. Significant trends of association were identified between selected components of the lower limb functional and kinematical asymmetries which were characterized by consistent laterality patterns. Multivariate asymmetry components and running injury patterns were independent. Only asymmetries in foot pronation during barefoot running tended to significantly differentiate between runners grouped by injury incidence. The phenomenon of functional and kinematic asymmetries in runners is warranted.

This study examined the effectiveness of a multi-dimensional education program in facilitating attitude changes in adolescent female athletes away from dysfunctional eating behaviours and restrictive body image. Although research is available for diagnosing and identifying the problems associated with dysfunctional eating behaviours and attitudes in female athletes, few preventative tools have been proposed in order to address the problem. This study involved the design, delivery and the evaluation of a proposed a multi-dimensional education model as a preventative tool. The research design involved 18 teenage female middle/long distance runners, aged between 13 and 19, who were registered with the ACT Cross Country Club. The study was a quantitative and qualitative investigation employing a pre and post test design and using the process of triangulation to increase the study's validity. It was proposed that a multi-dimensional education program might be effective in steering attitudes away from dysfunctional eating behaviours and body image and that a mixed method design may corroborate and elaborate on the findings of the study to strengthen the understanding of the potential benefits of such an education program has to its participants. Results showed that education proved to be a successful tool in facilitating attitudinal changes in a positive direction, across a number of variables such as menstrual functioning, nutrition, flexibility, strength, and general awareness, on what constitutes a balanced healthy athletic body.

Thesis (MScSportSc)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Neuromuscular control (NMC) plays a critical role in dynamic movement regulation such as running (Nyland et al., 2011) and injury prevention (Hübcher et al., 2010). This experimental study set out to determine whether an eight-week minimalist shoe training program influences NMC in recreational distance runners. Eleven experimental (EXP) (5 women; 6 men) (age 23.4 ± 2.98 yrs; VO2max 43.55 ± 5.04 ml.min-1.kg-1; BMI 22.61 ± 3.08 kg.m2; Training 17 ± 5km.w-1) and 12 control (CON) runners (7 women; 5 men) (age 25.42 ± 5.57 yrs; VO2max 43.67 ± 4.38 ml.min-1.kg-1; BMI 22.38 ± 3.12 kg.m2; Training 18 ± 6km.w-1) randomly completed an eight-week training program in either minimalist shoe (EXP) or their usual trainers (CON). Neuromuscular control components were measured before and after the intervention i.e. postural sway (Balance Biodex®), using the Athletic Single Leg (ASL) and modified Clinical Test of Sensory Integration and Balance (mCTSIB) tests, joint position sense (JPS) using joint angle reproduction tests (Biodex® Isokinetic Dynamometer), frontal and sagittal planes isokinetic strength testing, lower body electromyography (EMG) and kinematic measurements while participants ran on a treadmill. Plantar-dorsiflexion (PF/DF) or inversion eversion (IN/EV) proprioception did not differ between groups (p > 0.05). In selected trials EXP showed less deterioration in IN/ EV foot position error, when compared to CON, with medium to large practical significance. Athletic Single Leg scores for non-dominant (p < 0.01) and dominant M/L (p = 0.05) sway, and dominant overall sway (p = 0.04) improved in CON, with marked differences between genders. Dorsiflexor strength improved for 30∘.sec-1 and 60∘.sec-1speeds in CON (p < 0.01 & p = 0.04, respectively) and in the slower speed for EXP (p = 0.04). Plantar-flexion (PF) strength improved in EXP men (30∘.sec-1 p = 0.02; 60∘.sec-1 p = 0.02), while EXP women demonstrated a 7% deficit. At initial contact PF increased in EXP (8km.h-1 p = 0.01; 10km.h-1 p = 0.01; 12km.h-1 p = 0.01), with women showing a greater change in ankle angle (8km.h-1 p = 0.03; 10km.h-1 p = 0.02; 12km.h-1 p = 0.01) compared to men (8km.h-1 p = 0.05; 10km.h-1 p = 0.06; 12km.h-1 p = 0.05). Greater knee flexion (8km.h-1 ES = 0.64; 10km.h-1 ES = 0.49; 12 km.h-1 ES = 0.51) in EXP. Plantar-flexor pre-activation improved in EXP women, while co-activation improved in EXP men and total activation improved in both genders.Results suggest that women may require more time to transition into minimalist shoes. While minimalist shoes may moderately reduce foot position error, improve strength and muscle activation patterns, excessive plantar flexor muscle damage may reduce strength and muscle spindle proprioceptive feedback.
AFRIKAANSE OPSOMMING: Neuromuskulêre beheer (NMC) speel ‘n kritieke rol in dinamiese beweginsregulasie, soos met hardloop (Nyland et al., 2011) en beseringsvoorkoming (Hübscher et al., 2010). Hierdie eksperimentele studie het uit gesit om te bepaal of ‘n agt-week minimalistiese skoen oefenprogram NMB kan beïnvloed in rekreasie langafstand atlete. Elf eksperimentele (EXP) (5 vrouens, 6 mans) (ouderdom 23.4 ± 2.98 jr; VO2maks 43.55 ± 5.04 ml.min-1.kg-1; BMI 22.61 ± 3.08 kg.m2; Oefening 17 ± 5km.w-1) en twaalf kontrole (CON) hardlopers (7 vrouens, 5 mans) (ouderdom 25.42 ± 5.57; VO2maks 43.67 ± 4.38 ml.min-1.kg-1; BMI 22.38 ± 3.12 kg.m2; Oefening 18 ± 6 km.w-1) het lukraak ‘n agt-week oefenprogram voltooi, óf in minimalistiese skoene (EXP) of in hul gewone hardlooptekkies (CON). Neuromuskulêre beheer komponente was gemeet voor en na die intervensie i. e. posturale wieg (Balans Biodex®), met gebruik van Atletiese Enkelbeentoets (ASL) en die gemodifiseerde Kliniese Toets van Sensoriese Integrasie en Balans (mCTSIB), gewrigs posisie bewustheid (Biodex® Isokinetiese Dinamometer), frontale en sagitalle vlak isokinetiese kragtoetsing, onderlyf elektromiografie (EMG) en biomeganiese metings terwyl deelnemers op ‘n trapmeul gehardloop het. Plantaar dorsifleksie (PF/DF) of inversie eversie (IN/EV) propriosepsie het nie verskil tussen groepe nie (p > 0.05). In selektiewe proewe het EXP IN/ EV ‘n verminderde afname gehad in foutiewe voet posisieplasings, in vergelyking met CON, terwyl medium na groot praktiese betekenisvolle verskille. . Atleet enkel been toets tellings vir nie-dominant (p=0.001) en dominante M/L (p = 0.05) wieg, en dominant algehele wieg (p = 0.04) het verbeter in CON, met gemerkte verskille tussen geslagte. Dorsifleksor krag het verbeter vir 30∘.sec-1 en 60∘.sec-1spoed in CON (p = 0.01 en p = 0.04, onderskeidelik) en in die stadiger spoed vir EXP (p = 0.04). Plantaarfleksie (PF) krag het verbeter in EXP mans (30∘.sek-1 p = 0.02; 60∘.sek-1 p = 0.02), terwyl EXP vrouens ‘n 7% tekort gedemonstreer het. By initïele kontak het PF toegeneem in EXP (8km.h-1 p = 0.01; 10km.h-1 p = 0.01; 12km.h-1 p = 0.01), met vrouens wat ‘n groter verandering getoon het (8km.h-1 p = 0.03; 10km.h-1 p = 0.02; 12km.h-1 p = 0.01), in vergelyking met mans (8km.h-1 p = 0.05; 10km.h-1 p = 0.06; 12km.h-1 p = 0.05). Groter kniefleksie (8km.h-1 ES = 0.64; 10km.h-1 ES = 0.49; 12 km.h-1 ES = 0.51) in EXP. Plantaarfleksie pre-aktivering het verbeter in EXP vrouens, terwyl ko-aktivering verbeter het in EXP mans, en totale aktivering verbeter het in beide geslagte.Hierdie resultate stel voor dat vrouens moontlik meer tyd sal vereis om na minimalistiese skoene oor te skakel. Terwyl minimalistiese skoene matige verbetering in foutiewe voetposisieplasing, verbeterde krag en spieraktiveringspatrone kan veroorsaak, kan oormatige plantaarfleksie spierskade krag en spierspoel proprioseptiewe terugvoer ook verminder.

The purpose of this study was to assess the changes in maximal oxygen consumption and cardiorespiratory responses to maximal treadmill exercise of men, who engaged in intense physical training for more than 35-years. Thirteen men were first studied in 1969 and were re-examined in 1992 as a 25-year follow-up. The men were divided into two groups, group 1 (G1) and group 2 (G2). G1 (current age = 54.6 years) consisted of seven men who were Division I cross country runners in the late 1960's, and G2 (current age = 67.5 years) were highly active at the initial testing and were 14 years older than the men of G1 at all test dates. A maximal exercise test revealed a significant decrease in absolute and realtiveVO2ma, over the 35-years for both G1 and G2. G2 experienced a significant decline in VO2max when expressed in relative and absolute terms after the age of 56.5 years which occurred after the 25-year test. Maximal heat rate decreased over the 35-year period for both G1 (187.7 to 165.8 bpm) and G2 (181 to 164.7bpm), however only GI revealed a trend between the 25-and 35-year tests. O2pulse significantly decreased from the initial testing to the 35-year period in G2 (23.1 to 19.5 ml/beat). Body composition changes were evident with aging in that both GI and G2 had a significant increase in percent body fat over the 35-years however, only Gl had a significant increase in body weight at both the 25-and 35-year follow-up.These data suggest that aging and a reduced training regimen may have a significant effect upon VO2m and cardiorespiratory and body composition measures. It appears that after the age of 56 years, a greater reduction in VO2max occurs, which is accompanied by greater changes in stroke volume. Although the aerobic capacity of these men declined over the 35-year period, the values obtained by all men far exceeded the values reported for sedentary and less active men in other studies. Therefore, as previously reported, aging is associated with a reduction in aerobic capacity, however continued endurance training can reduce the rate at which aerobic capacity declines.
Fisher Institute for Wellness and Gerontology

To measure the differences in ground reaction forces between running shoes, racing flats, and distance spikes, twenty intercollegiate distance runners ran across a force plate at 6.7m/s (for males) and 5.74m/s (for females) in each of the three types of shoes. In order to control for differences in foot strike, only subjects who had a heel strike were included in the data analysis (N=16). Repeated-measures ANOVA and Tukey's post-hoc test (p<0.05) revealed loading rate and impact peak to be significantly increased in the flats and spikes compared to running shoes. Stiffness in spikes was significantly higher than in running shoes. Stance time in spikes and flats was decreased. These results can be used to better inform competitive runners, coaches, and trainers of the risks and performance benefits when determining the frequency and duration of the use of competitive footwear in training.

Thesis (MSpor)--University of Stellenbosch, 2007.
ENGLISH ABSTRACT: Various types of post-exercise recovery strategies have become part of the modern athlete’s daily routine. It is a well known that inadequate recovery will prolong the time it takes for the runner’s body to adequately adapt between training sessions and competitions. Anecdotal claims have been made about compression garments as a beneficial method to assist recovery after training sessions and competitions. Until now limited scientific research has addressed the influence that compression garments have on the recovery process after sporting activities. The benefits of compression garments, as a possible recovery modality, are that it is costeffective, practical and easily obtainable. This study endeavored to investigate the possible influence that compression garments may have on middle-aged long distance runners’ recovery rate after a prolonged run. This is the first study that has focused on compression garments as a post-exercise recovery modality for experienced middle-aged long distance runners. The other unique aspect of this study is the prolonged two-hour treadmill protocol that was used to induce muscle soreness. In addressing the aims, a randomized, crossover study design was used to investigate the possible benefits that the high pressure (CCL II 23-32 mmHg (mercury millimeter)) graduated compression garments may bring about. Seven competitive male long distance runners (height: 176.0 ± 8.6 cm; body mass: 92.5 ± 11.8 kg; VO2max: 45.7 ± 5.0 mL.kg-1.min-1) between the ages of 36 to 51 years volunteered for the study. The runners had to complete a two-hour treadmill run at 70 % of their predetermined maximum aerobic capacity, followed by a monitored 72-hour recovery period. The first part of the prolonged run was a 90–minute variant gradient run, followed by a 30-minute downhill run. Each subject acted as his own control and visited the Stellenbosch University’s Sport Physiology Laboratory (South Africa) on two occasions, separated by 7 to 28 days. One test was done with a compression garment (23 to 32 mmHg) and the other without. Testing included the measurement of lower limb circumferences (ankle, calf, mid- and proximal thigh), plasma lactate, lactate dehydrogenase and creatine kinase concentrations and the completion of subjective questionnaires on perceived muscle soreness (visual analog scale (VAS)). The lower extremities’ functional ability was determined with a time to exhaustion (TTE) step test, a vertical jump test (VJ) and modified sit-and-reach flexibility test. Preexercise measurements were taken and immediately after and during the 72 hour after the treadmill run and repeated for the second bout. The main outcomes of this study showed that the two-hour treadmill run induced delayed onset of muscle soreness, with and without the compression garment. Evidence of this was a significant rise in plasma creatine kinase (CKp) over the duration of both trials (P < 0.05). The compression garment significantly reduced swelling in the calf muscle (41.0 ± 0.2 vs. 41.5 ± 0.5 mm; P < 0.002). Runners showed a lower perceived muscular pain and discomfort while performing functional knee movements at 24 and 48-hours after the two-hour run with the compression garment (1.2 ± 1.6 vs. 3.8 ± 2.4 cm and 0.9 ± 1.8 vs. 3.0 ± 2.6 cm on VAS, respectively; P < 0.05). Significant differences in perceived muscle soreness between the WCG and WOCG trials were observed at 24-hours after the run during rest (0.1 ± 0.2 vs. 0.4 ± 0.8 cm; P = 0.02) and with stretching (1.9 ± 1.2 vs. 3.5 ± 2.5 cm on VAS P = 0.02). The perceived pain associated with pressure was significantly lower with the compression garment at 24 (307 %) and 48-hours (237 %) after the run (P < 0.05). Blood lactate levels were reduced during the acute phase of recovery at 10 (1.8 ± 0.5 vs. 2.2 ± 0.9 mmol.L-1; P = 0.05) and 30 minutes (1.8 ± 0.5 vs. 2.4 ± 0.4 mmol.L-1; P = 0.01) after the run, as well as plasma creatine kinase concentrations were statistically significantly lower at 24-hours (238.3 ± 81.3 vs. 413.3 ± 250.8 units.L-1; P = 0.005) after exercise with the compression garment. The two-hour treadmill run and the compression garment had no significant influence on the runners’ lower limb strength, power, endurance or flexibility (P > 0.05). Compression garments demonstrated the potential to enhance recovery after prolonged strenuous exercise in well trained middle-aged runners. In addition, runners did not experience additional fatigue from the moderate to high pressure garments. The effect of higher pressure compression garments on athletic performance and the psychological influence of the garment need further investigation.
AFRIKAANSE OPSOMMING: Verskillende tipes naoefening herstelstrategië, vorm deel van die moderne atleet se daaglikse routine. Dit is wel bekend dat onvoldoende herstel sal beteken dat die atleet se liggaam langer sal neen om aan te pas tussen inoefen sessies en kompetisies. Sekere bewerings word al gemaak omtrent die voordeligheid van kompressiesokkies tydens die herstelperiode na oefening sessies en kompetisies. Tot nou toe was daar beperkte wetenskaplike navorsing oor die invloed van kompressie sokkies of die herstel proses van sport aktiwiteite. Die voordeel van kompressie sokkies as ‘n moontlike herstelmetode, is dat dit koste-effektief, prakties en maklik verkrybaar is. Hierdie studie poog om ‘n ondersoek in te stel na die moontlike invloed wat kompressie sokkies op middeljarige lang-aftstandatlete se herstelperiode sal hê na ‘n verlengde hardloopsessie. Hierdie is die eerste studie wat konsentreer op kompressie sokkies as ‘n naoefenings hersteltegniek vir ervare middeljarige lang-afstandatlete. Die ander unieke aspek van die ondersoek is die langdurige tweeuur trapmeul protokol wat gebruik word om spierpyn te veroorsaak. Om die doel te bereik, is ’n lukrake oorkruis studie gebruik om ondersoek in te stel na die moontlike voordele van die hoë druk (CCL II 23-32 mmHg) kompressie sokkies. Hierdie sokkies toon ’n progressiewe verhooging van druk vanaf die enkle tot onder die knieskyf. Sewe mededingende langafstand atlete (lengte : 176.0 ± 8.6 cm; liggaams massa: 92.5 ± 11.8 kg; VO2maks: 45.7 ± 5.0 mL.kg-1.min-1) tussen die ouderdomme van 36 en 51 jaar, het aan die studie deel geneem. Die wedlopers moes ‘n twee-uur lange trapmeul toets voltooi, teen 70% van hul vooraf bepaalde maksimum aerobiese kapasiteit. Dit is gevolg deur ‘n gemonitorde 72-uur herstel periode. Die eerste deel van die twee-uur hardloop sessie was ‘n 90-minuut afwisselende opdraende en afdraende hardloop stel, wat gevolg is deur a 30-minuut afdraande deel. Elke deelnemer was sy eie kontrole en het op twee geleenthede die Stellenbosch Universiteit se Sport Fisiologiese Laboratorium (Suid Afrika) besoek. Die twee besoeke is tussen 7 en 28 dae geskei. Een toets is met kompressie sokkies gedoen (23 – 32 mmHg) en die ander sonder. Die toetse het die volgende behels: laer been omtrekke (enkel, kuit, middel- and bo dy), die versameling en ontleding van bloed monsters vir plasma laktaat, laktaat dehydrogenase and kreatine kinase konsentrasies en die voltooing van subjektiewe vraelyste oor die graad van spierpyn ervaaring (“visual analog scale” (VAS)). Die onderlyf funksionele vermoëns is bepaal met ’n tyd tot uitputtings traptoets, ‘n vertikale sprong toets en ‘n gewysige sit-en-strek soepelheids toets. Data is voor die oefeninge in gevorder asook direk daarna, en gedurende die 72 uur na die trapmeul draf. Die metings vir die tweede sessie is herhaal. Die hoof uitkomste van die studie het gewys dat die twee-uur trapmeulsessie het spierpyn veroorsaak, met en sonder die kompressie sokkies. Die bewys hiervan was ‘n betekensvolle toename in plasma kreatien kinase (CKp) oor die tydperk van albei oefening toetse (P<0.05). Die kompressie sokkies het die swelling in die kuitspiere verminder, in vergelyking met die toetse sonder kompressie sokkies (41.0 ± 0.2 vs. 41.5 ± 0.5 mm; P < 0.002). Wedlopers met die kompressie sokkies het minder spierseerheid en ongerief aangeteken toe hulle knie beweegings gedoen het op 24 en 48-uur na die twee-ure trapmeul toets (1.2 ± 1.6 vs. 3.8 ± 2.4 cm op VAS en 0.9 ± 1.8 vs. 3.0 ± 2.6 cm op VAS, onderskeidelik; P < 0.05). Betekenisvolle verskille is waargeneem tussen die toetse met en sonder kompressie sokkies, op 24-uur na die twee-ure toets gedurende rus (0.1 ± 0.2 vs. 0.4 ± 0.8 cm op VAS; P = 0.02) en met strek oefeninge (1.9 ± 1.2 vs. 3.5 ± 2.5 cm op VAS P = 0.02). Die pyn wat ervaar was met drukking, was betekenisvol minder met die kompressie sokkies op 24 (307 %) en 48-uur (237 %) na die trapmeul sessie (P < 0.05). Bloed laktaat konsentrasie in die sirkulasie was verlaag gedurende die akute fase van die herstelings periode op 10 (1.8 ± 0.5 vs. 2.2 ± 0.9 mmol.L-1; P = 0.05) en 30 minute (1.8 ± 0.5 vs. 2.4 ± 0.4 mmol.L-1; P = 0.01) na die hardloop sessie, sowel as die plasma kreatine kinase konsentrasie was statisties betekenisvol laer by 24 uur (238.3 ± 81.3 vs 413.3 ± 250.8 eenhede L-1; P = 0.005) na die hardloop sessie met die kompressie sokkies. Die twee-ure trapmeul toets en die kompressie sokkies het geen betekenisvolle invloed gehad op die wedlopers se onderlyf ledemate se plofkrag, uithouvermoë of soepelheid (P > 0.05) nie. Kompressie sokkies het gewys dat dit potensiaal het om met herstel te help na lang en harde oefening in geoefende middeljarige atlete. Nietemin is daar verdere wetenskaplike navorsing nodig om dit te bevestig. Wedlopers het nie addisionele vermoeienis van die drukking van kompressie sokkies ervaar nie. Sterker drukkende kompressie sokkies sowel as die sielkundige invloed van die sokkies benodig verdere navorsing.spierpyn ervaaring (“visual analog scale” (VAS)). Die onderlyf funksionele vermoëns is bepaal met ’n tyd tot uitputtings traptoets, ‘n vertikale sprong toets en ‘n gewysige sit-en-strek soepelheids toets. Data is voor die oefeninge in gevorder asook direk daarna, en gedurende die 72 uur na die trapmeul draf. Die metings vir die tweede sessie is herhaal. Die hoof uitkomste van die studie het gewys dat die twee-uur trapmeulsessie het spierpyn veroorsaak, met en sonder die kompressie sokkies. Die bewys hiervan was ‘n betekensvolle toename in plasma kreatien kinase (CKp) oor die tydperk van albei oefening toetse (P<0.05). Die kompressie sokkies het die swelling in die kuitspiere verminder, in vergelyking met die toetse sonder kompressie sokkies (41.0 ± 0.2 vs. 41.5 ± 0.5 mm; P < 0.002). Wedlopers met die kompressie sokkies het minder spierseerheid en ongerief aangeteken toe hulle knie beweegings gedoen het op 24 en 48-uur na die twee-ure trapmeul toets (1.2 ± 1.6 vs. 3.8 ± 2.4 cm op VAS en 0.9 ± 1.8 vs. 3.0 ± 2.6 cm op VAS, onderskeidelik; P < 0.05). Betekenisvolle verskille is waargeneem tussen die toetse met en sonder kompressie sokkies, op 24-uur na die twee-ure toets gedurende rus (0.1 ± 0.2 vs. 0.4 ± 0.8 cm op VAS; P = 0.02) en met strek oefeninge (1.9 ± 1.2 vs. 3.5 ± 2.5 cm op VAS P = 0.02). Die pyn wat ervaar was met drukking, was betekenisvol minder met die kompressie sokkies op 24 (307 %) en 48-uur (237 %) na die trapmeul sessie (P < 0.05). Bloed laktaat konsentrasie in die sirkulasie was verlaag gedurende die akute fase van die herstelings periode op 10 (1.8 ± 0.5 vs. 2.2 ± 0.9 mmol.L-1; P = 0.05) en 30 minute (1.8 ± 0.5 vs. 2.4 ± 0.4 mmol.L-1; P = 0.01) na die hardloop sessie, sowel as die plasma kreatine kinase konsentrasie was statisties betekenisvol laer by 24 uur (238.3 ± 81.3 vs 413.3 ± 250.8 eenhede L-1; P = 0.005) na die hardloop sessie met die kompressie sokkies. Die twee-ure trapmeul toets en die kompressie sokkies het geen betekenisvolle invloed gehad op die wedlopers se onderlyf ledemate se plofkrag, uithouvermoë of soepelheid (P > 0.05) nie. Kompressie sokkies het gewys dat dit potensiaal het om met herstel te help na lang en harde oefening in geoefende middeljarige atlete. Nietemin is daar verdere wetenskaplike navorsing nodig om dit te bevestig. Wedlopers het nie addisionele vermoeienis van die drukking van kompressie sokkies ervaar nie. Sterker drukkende kompressie sokkies sowel as die sielkundige invloed van die sokkies benodig verdere navorsing.

The purpose of this investigation was to examine the effects of 20 years of distance running training on the morphological and functional characteristics of skeletal muscle. Sixty men (current age = 49.2 ± 2.4 yr.) were first studied between 1966-1974 when they were all highly trained. Based on their training regimens in the interim between testing, subjects were described as highly trained (HI), fitness trained (FIT) or untrained (UT). Gastrocnemius muscle biopsy samples revealed an increase (p<0.05) in the proportion of type I fibers of the FIT (52.9 ± 5.3 vs. 61.9 ± 5.2%) and UT (56.3 ± 2.9 vs. 65.4 ± 3.8%) groups, while the HI group, who was initially characterized by a high percentage (>70%) of type I muscle fibers, was unchanged. Among the elite distance runners who had continued high volume, high intensity running, succinate dehydrogenase (SDH) activity and type I and type II muscle fiber areas were similar between evaluations. In 1993, the HI group had higher (p<0.05) SDH and citrate synthase (CS) activities compared with the FIT and UT groups, whereas phosphorylase activity did not differ. Capillary density and capillary-to-fiber ratio were also greater (p<0.05) in the HI group compared with the other two groups. Isokinetic plantar flexion strength at 60°/s and 180°/s and cross-sectional area (CT scans) of the lower leg (gastrocnemius and soleus) were similar among groups. These data suggest that aging may have a significant effect upon the distribution of muscle fibers and may be dependent upon fiber composition as a young adult. In addition, sustained endurance training appears to maintain the oxidative characteristics of the skeletal muscle, but does not provide an advantage in absolute calf muscle strength compared with individuals who train considerably less or not at all.
School of Physical Education

Exercise-induced fatigue may be caused by increases in cerebral serotonin resulting in symptoms of central fatigue (i.e. decreased mood, and increased stress and sleepiness). Branched-chain amino acid (BCAA) supplementation is one intervention that can reduce symptoms of central fatigue by competing for the tryptophan transporter reducing serotonin synthesis. Psychological monitoring tools such as The Daily Analysis of Life Demands for Athletes (DALDA) Questionnaire can be used to study symptoms of central fatigue by identifying sources of general and sport-specific stress as well as an athlete’s reaction to stressors. PURPOSE: To examine the response of BCAA on stress perception of trained collegiate distance runners using DALDA. METHODS: 8 collegiate distance runners (men n=4, women n=4) took BCAA supplement (SUP) (0.08g/kg) or placebo (PLA) daily for 6 weeks, alternating conditions week to week. Each morning athletes filled out the 34-item DALDA prior to training by selecting one of 3 answers corresponding to stress symptoms: A = “feel worse than normal”, B= “feel normal”, C= “feel better than normal”. Response ratios were generated for each of the 3 answers for each condition (SUP or PLA) by taking total number of responses for each answer over number of answers overall. Response ratios were calculated as weekly mean ± SD and MANOVA was used for analysis. The alpha criterion was set to p<0.05. RESULTS: Statistical significance was found (p<0.01), and further analyses were done to examine changes from week to week. On average, athletes reported fewer ‘A’ responses in SUP weeks than PLA weeks (SUP: 9.27% ± 2.21%; PLA: 13.46% ± 7.29%), while response percentage for ‘C’ was the same between both conditions (SUP: 11.78 ± 2.12%; PLA: 11.24% ± 2.32%). Changes from SUP weeks to PLA weeks produced noticeable changes in ‘A’ responses (e.g.: 14.36% SUP week to PLA week; -9.95% from PLA week to SUP week). CONCLUSIONS: Results from DALDA revealed a noticeable change in the stress response of the athletes from condition to condition. The athletes reported higher instances of feeling “worse than normal” during PLA weeks and fewer instances of feeling “worse than normal” during SUP weeks. These results indicate that BCAA supplementation seems to be an effective means of reducing the stress perception in these collegiate distance runners.

Includes bibliographical references (p. 244-259)
It is likely that masters runners may experience an intolerance to exercise primarily due to the age-related changes in their bodies, and specifically of those systems and organs most utilised during running. A more disturbing phenomenon, however, is that of younger runners becoming exercise intolerant. One study described exercise intolerance in athletes who were only 40 +/- 10 years old. The muscle of these athletes had greater levels of markers of structural pathology and showed evidence of having undergone more regeneration compared to age- and mileage-matched apparently healthy athletes. The authors attributed their intolerance to exercise to their large volumes of endurance training and racing which compromised their skeletal muscle. Therefore, the objective of this thesis was to examine the effects of chronic exposure to endurance running on the athlete, with particular emphasis on skeletal muscle.