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1
Weihrer, Sylvia J. "Changes in blood lactate concentration during active recovery at sub-lactate threshold, lactate threshold, and supra-lactate threshold exercise intensities." Thesis, University of Ottawa (Canada), 1991. http://hdl.handle.net/10393/7892.
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The purpose of this investigation was to identify the intensity of recovery exercise, relevant to endurance event performance, that would result in the most rapid times for half decrease in blood lactate concentration, following 2 minutes of cycling at maximal rates. Three recovery exercise intensities were investigated: (a) 7% of the maximal rate of oxygen consumption (VO$\sb2$) (LT $-$7%), (b) lactate threshold VO$\sb2$ ( LT), and (c) 7% of VO$\sb2$max above lactate threshold VO$\sb2$ (LT +7%). Seven well-trained male cyclists (mean VO$\sb2$max 4.6 $\pm$ 0.49 L $\times$ min$\sp{-1}$ participated as subjects in the investigation. Each subject completed seven separate cycling tests: (a) one combined lactate threshold-VO$\sb2$max test, (b) three constant work rate tests, and (c) three tests of recovery following supra-lactate threshold exercise (surge-recovery tests). The absolute values of blood lactate concentration were significantly different across the three recovery intensities (p .01). At the end of the 20 minute recovery period the mean blood lactate concentrations were 1.57, 2.49, and 4.17 mmol $\times$ L$\sp{-1}$ for the LT $-$7%, LT%, and LT +7% recovery intensities, respectively. Times for half decrease in blood lactate concentration were calculated. There were no significant differences in these half decrease times between the three recovery intensities (p .01). (Abstract shortened by UMI.)
2
Buckley, Jonathan David. "Human lactate kinetics : training effects /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phb924.pdf.
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Alkhatib, Ahmad. "Interrelationship between blood lactate concentration, carbohydrate, and fat utilisation." Thesis, University of Essex, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446011.
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Russell, Morgan D. "The Effect of Caffeine Gum Administration on Blood Glucose and Blood Lactate during Cycling to Exhaustion." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1217006383.
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Peeters, Mon Jef. "The effect of recovery strategies on high-intensity exercise performance and lactate clearance." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2735.
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PURPOSE: To compare the effects of recovery intensity on performance of a bicycle sprint task
and blood La⁻ clearance. METHODS: On three separate days twelve trained male subjects (27.4
± 3.9 yrs) performed three supramaximal exercise (SE) bouts at 120% of maximum aerobic
power (MAP) for 60% of the time to exhaustion (TTE). Bouts were separated by 5 mm of
passive recovery (PR), active recovery (AR) or combined active recovery (CAR). The third bout
was followed by a 14 mm recovery. Recovery intensities were: PR (rest), AR at 50% of the
workload difference between the individual anaerobic threshold (IAT) and the individual
ventilatory threshold (IVT) below the IVT ( ₋50%ΔT), or CAR at the IAT workload for 5 mm
and at the ₋50%ΔT workload for 9 mm. Five 10 s sprints were performed 2 mm post-recovery.
Blood lactate (La⁻) concentration, power parameters (Peak Power (PP), Mean Power (MP),
Fatigue Index (Fl), and Total Work (TW)), Heart Rate (HR), and Oxygen Uptake (VO₂) were
compared using repeated-measures ANOVA. Pairwise comparisons and dependent T-tests were
performed to analyze differences. RESULTS: Mean La⁻ values for AR and CAR were lower
than PR (9.7 ± 3.5, 9.5 + 3.5, 11.7 + 3.6, respectively, p≤0.05). La⁻ was significantly lower with
CAR versus PR at the 3rd, 6th, 9th, and 14th mm of recovery (p≤0.05). AR versus PR La⁻ was
lower at the 3rd, 6th, 9th, and 14th min of recovery (p≤0.05). Mean MP was greater in the AR group
compared to the PR group (800.1 ± 114.5 vs 782.2 ± 111.7 W, p≤0.05). TW during AR was
greater than PR (p≤0.05) but not CAR (p≤0.05, 40003.3 ± 5110.2, 39108.3 ± 4852.9, 39335.8 ±
5022.6 J, respectively). CONCLUSIONS: AR and CAR both demonstrated improved La⁻
clearance when compared to PR, but differences in La⁻ clearance did not determine performance
on the sprint task. AR resulted in more TW than PR and greater maintenance of power over the sprints.
6
Gray, Susan Caroline. "The effects of differing warm-up procedures on the metabolic response during subsequent short-duration high-intensity exercise." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366838.
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Nitzsche, Nico, Lutz Baumgärtel, Christian Maiwald, and Henry Schulz. "Reproducibility of Blood Lactate Concentration Rate under Isokinetic Force Loads." MDPI AG, 2018. https://monarch.qucosa.de/id/qucosa%3A33156.
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(1) Background: Maximum isokinetic force loads show strongly increased post-load lactate concentrations and an increase in the maximum blood lactate concentration rate ( V˙ Lamax), depending on load duration. The reproducibility of V˙ Lamax must be known to be able to better assess training-related adjustments of anaerobic performance using isokinetic force tests. (2) Methods: 32 subjects were assigned to two groups and completed two unilateral isokinetic force tests (210° s−1, Range of Motion 90°) within seven days. Group 1 (n = 16; age 24.0 ± 2.8 years, BMI 23.5 ± 2.6 kg m−2, training duration: 4.5 ± 2.4 h week−1) completed eight repetitions and group 2 (n = 16; age 23.7 ± 1.9 years, BMI 24.6 ± 2.4 kg m−2, training duration: 5.5 ± 2.1 h week−1) completed 16 repetitions. To determine V˙ Lamax, capillary blood (20 µL) was taken before and immediately after loading, and up to the 9th minute post-load. Reproducibility and variability was determined using Pearson and Spearman correlation analyses, and variability were determined using within-subject standard deviation (Sw) and Limits of Agreement (LoA) using Bland Altman plots. (3) Results: The correlation of V˙ Lamax in group 1 was r = 0.721, and in group 2 r = 0.677. The Sw of V˙ Lamax was 0.04 mmol L−1 s−1 in both groups. In group 1, V˙ Lamax showed a systematic bias due to measurement repetition of 0.02 mmol L−1 s−1 in an interval (LoA) of ±0.11 mmol L−1 s−1. In group 2, a systematic bias of −0.008 mmol L−1 s−1 at an interval (LoA) of ±0.11 mmol L−1 s−1 was observed for repeated measurements of V˙ Lamax. (4) Conclusions: Based on the existing variability, a reliable calculation of V˙ Lamax seems to be possible with both short and longer isokinetic force loads. Changes in V˙ Lamax above 0.11 mmol L−1 s−1 due to training can be described as a non-random increase or decrease in V˙ Lamax.
8
Duvillard, Sergei Petelin von. "Determination of the Lactate Threshold by Respiratory Gas Exchange Measures and Blood Lactate Levels During Incremental-Load Work." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc331769/.
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The purpose of this investigation was to examine the change in pulmonary ventilation (V_E), ventilatory equivalent of oxygen (VE_O_2) and lactic acid (LA) in relation to oxygen uptake (V_O_2) as predictors of the lactate threshold (LT). Eight healthy male (21.9 ± 3.0 years) subjects conducted three incremental-load tests. In each test the initial work rate consisted of 4 minutes of unloaded pedaling ("0" load) followed by incremental-load work of 360 Kgm • min^-1 at 60 rpm for trial I and trial II, while during trial III the work rate consisted of 540 Kgm • min^-1 of incremental-load work at 90 rpm. Work load was increased every third minute until the subject reached voluntary exhaustion. Blood samples from a forearm vein were collected during trial II (60 rpm) and trial III (90 rpm) and analyzed for lactic acid. In our subjects the measured (x̄ ± SD) lowest VE_O_2 for O_2 in relation to V_O_2 for trial I of 22.9 ± 1.9 occurred at a V_O_2 of 1.27 ± 0.8 L • min^-1. For trial II the VE_O_2 of 22.4 ± 1.3 occurred at a V_O_2 of 1.30 ± 0.09 L • min^-1, while for trial III a VE_O_2 of 24.4 ± 2.5 occurred at a V_O_2 of 1.84 ± 0.15 L • min^-1. The lowest VE_O_2 and onset of LA accumulation as calculated from individual exponential equations relating V_E to V_O_2 yielded V_O_2 values at 1.77 ± 0.18 L • min^-1 and 1.74 ± 0.25 L • min^-1 for trial II, and 1.83 ± 0.19 L • min^-1 and 2.02 ± 0.53 during trial III. Utilizing ln[LA]-ln V_O_2 equations, the LT occurred at a V_O_2 of 1.30 ± 0.07 L • min^-1 during trial II and 1.85 ± 0.12 L • min^-1 during trial III. It was concluded that during the 60 rpm test that the lactate threshold was best predicted by measured lowest VE_O_2 and the plot of the In[LA] to In V_O_2 relationship. The methods used in this study provide a valid and reliable estimate of the lactate threshold and support the use of measured lowest VE_O_2 , a respiratory gas exchange measure, as an indirect measure of the lactate threshold.
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Anderson, Scott Cameron. "Blood lactate reduction at three recovery intensities following severe rowing excercise." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26348.
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The purpose of this study was to observe the differences in rates of blood lactate reduction (BLR) at three recovery intensities (40% VO₂max,
60% V02max, and combined recovery ) when subjects are highly trained
and aerobically fit. Eight well-trained oarsmen (age = 23.2 yr, Ht = 189.6 cm, Wt = 85.3 kg, VO₂max = 5.2 1 / min or 61.6 ml / kg min⁻¹) were tested
in one pre-experimental procedure and three experimental treatments. The pre-experimental procedure involved the determination of VO₂max,
and the loads at which 40 -, 50 -, and 60% VO₂max occurred from a
progressive load VO₂max. The three experimental treatments each
involved three one minute maximal load intervals on the rowing
ergometer to elevate blood lactate, followed by a 30 minute randomly assigned recovery on the rowing ergometer at either 40% VO₂max (40R),
60% VO₂max (60R), or combined recovery (CR). Blood samples, from an
indwelling catheter placed in the cephalic vein, were taken at t=0,1, 2, 3, 4, 5, 6, 9,12,15,18, 21, 24, 27, and 30 min of recovery. Analysis of plasma samples revealed a mean resting blood lactate concentration ( [ Bla ] ) of 1.2 mM and a mean peak [ Bla ] following maximal exercise of 16.3 mM. ANOVA indicated that no significant differences occurred between the rates of lactate reduction for the three treatments (p<.055). With p<.055 and an effect size of eta=.31, further testing using a post-hoc multicomparison analysis revealed a significantly faster (p<.05) rate of BLR during the 60R treatment when compared to the rate of BLR for 40R. No further differences were revealed between any of the other comparisons (40R vs CR, or 60R vs CR). The significant differences between the rate of BLR for 60R compared to 40R may be due to the subjects' high aerobic fitness, the specific nature of both their training and the recovery task, and physiological adaptations related to a high fitness level.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
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Anderson, Gregory Steven. "The relationship between excess CO2 and blood lactate in elite cyclists." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28534.
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This study examined the relationship between expired non-metabolic CO₂ (EX CO₂) and the accumulation of blood lactate, while emphasis was placed on the ventilatory (EX CO₂ and VE/VO₂) and lactate threshold relationship. Twenty-one elite cyclists (15 males, 6 females) performed a progressive intensity bicycle ergometer test (PIT) during which ventilatory parameters were monitored on-line at 15 second intervals, and blood lactate sampling occured on each minute. Threshold values were determined for each of the three indices; excess CO₂ (EXTT), VE/V0₂ (VVTT), and blood lactate (LATT). The three threshold values (EXTT, VVTT, LATT) all correlated significantly (P<0.001) when each was expressed as an absolute VO₂ (1/min). A significant RM ANOVA (F=8.41, P<0. 001) and post hoc correlated t-tests demonstrated significant differences between the EIXTT and LATT (P<0.001) and the EXTT and VVTT values (P<0.025).
The LATT occured at an average blood lactate concentration of 3.35 mmol/1, while the mean expired excess CO₂ volume at the EXTT was 14.04 ml/kg/min. Over an 11 minute range across the threshold values (EXTT and LATT), which were used as relative points of reference, the expired EXC02 volume (ml/kg/min) and blood lactate concentration (mmol/1) correlated significantly (r=0. 69, P<0. 001). Higher individual correlations over the same period of time Curriculum and Pedagogy (EDCP), Department of
Graduate
11
Danielsson, Sebastian. "Physiological characteristics of sodium lactate infusion during resistance exercise." Thesis, Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:gih:diva-5782.
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Previous studies that utilized sodium lactate infusion did not use resistance exercise protocol or analyzed muscle biopsies, or performed sex specific analysis. Aim: We initiated a project where resistance exercise was performed with low and high levels of lactate, acquired by venous lactate infusion where the specific aim of this study was to investigate and chart the physiological characteristics of sodium lactate infusion during a bout of resistance exercise on whole group level and sexes separated Method: A randomized, placebo controlled, cross-over design was implemented where male (n = 8) and female (n = 8) subjects accustomed to resistance exercise visited the laboratory three times for preliminary testing and training familiarization. In the following two experimental trials subjects arrived in an overnight fasted state. A resting state muscle biopsy was extracted from m. vastus lateralis and repeated blood samples were initiated which followed by 20 minute of baseline infusion of either infusate in resting state at 0.05 mmol/kg/min infusion rate with additional bolus doses during subsequent exercise. Following a brief warm up, unilateral knee-extensions (6 x 8-10 reps at 75% of 1-RM) were performered with or without venous infusion of sodium lactate, with volume matched saline as control. Exercise load and volume were matched between trials. Four additional biopsies were extracted at post-exercise, recovery period, and 24-hour post-exercise. Results: Sodium lactate infusion vs saline infusion respectively during resistance exercise yielded significantly higher blood lactate with sodium lactate (6.78 ± 0.33 mmol/l vs 2.99 ± 0.17 mmol/l), plasma lactate (8.86 ± 0.39 mmol/l vs 4.39 ± 0.22 mmol/l), blood sodium (143 ± 0.4 mmol/l vs 142 ± 0.3 mmol/l), blood pH (7.42 ± 0.01 vs 7.34 ± 0.01), but lower blood potassium (3.9 ± 0.1 mmol/l vs 4.2 ± 0.1 mmol/l), all immediately following exercise. Sodium lactate infusion elicited main effect of trials and muscle lactate increased from baseline (8.5 ± 0.9 mmol·kg-1 dw vs 7.0 ± 0.6 mmol·kg-1 dw) to post-exercise (31.5 ± 2.8 mmol·kg-1 dw vs 26.9 ± 3.2 mmol·kg-1 dw) with sodium lactate and saline infusion respectively. Blood glucose, hemoglobin and muscle pH was not affected by sodium lactate infusion. Conclusions: Utilization of the sodium lactate infusion method during a bout of resistance exercise may be used as tool to effectively increase blood/plasma lactate and, to lesser extent, muscle content of lactate. However, a concomitant slightly alkalizing effect of blood likely will occur.Tidigare studier som använt natriumlaktat infusion använde inte styrketräningsprotokoll, eller analyserade muskelbiopsier eller utförde könsspecifika analyser. Syfte och frågeställningar: Vi initierade ett projekt där styrketräning utfördes med låga eller höga nivåer av laktat som erhölls genom venös natriumlaktat infusion med det specifika syftet att undersöka och kartlägga fysiologisk karakteristiska av naturiumlaktat infusion under styrketräningsövning på helgrupps- och könsseparerad nivå. Följande frågeställningar inrättades; hur påverkar natriumlaktat infusion under styrketräning helblod- och plasma laktat, glukos, natrium, kalium, plasma volym genom hemoglobin och hematokrit, blod pH, muskellaktat- och muskel pH samt om skillnader i respons finns efter att könsspecifika analyser utförts på dessa variabler. Metod: En randomiserad, placebokontrollerad cross-over design implementerades där styrketräningsvana män (n = 8) och kvinnor (n = 8) besökte laboratoriet tre gånger för preliminäraför tester och träningsfamiliarisering. I efterföljande två experimentella försök anlände försökspersonerna i ett över nattligt fastande tillstånd. En baslinje biopsi extraherades från m. vastus lateralis och repeterade blodprover initierades med efterföljande 20 minuter av baslinje infusion av endera infusat i vilotillstånd med 0.05 mmol/kg/min infusionshastighet med ytterligare bolusdoser under efterföljande träning. Efter en kort uppvärmning utfördes unilaterala knäextensioner (6 x 8-10 reps vid 75% av 1-RM) med eller utan venös infusion av natrium laktat, med volymmatchande saltlösning som kontroll. Träningsbelastning och volym matchades mellan försök. Ytterligare fyra biopsier extraherades vid efter-träning, återhämtningsperiod, och efter 24 timmar. Resultat: Natriumlaktat respektive saltlösnings infusion under styrketräning gav signifikant högre blodlaktat med natriumlaktat infusion (6.78 ± 0.33 mmol/l mot 2.99 ± 0.17 mmol/l), plasmalaktat (8.86 ± 0.39 mmol/l mot 4.39 ± 0.22 mmol/l), blodnatrium (143 ± 0.4 mmol/l mot 142 ± 0.3 mmol/l), blod pH (7.42 ± 0.01 mot 7.34 ± 0.01), men lägre blod kalium (3.9 ± 0.1 mmol/l mot 4.2 ± 0.1 mmol/l), alla direkt efter träning. Natriumlaktat infusion framkallade huvudeffekt av försök och muskellaktat ökade från baslinje (8.5 ± 0.9 mmol·kg-1 dw mot 7.0 ± 0.6 mmol·kg-1 dw) till efter-träning (31.5 ± 2.8 mmol·kg-1 dw mot 26.9 ± 3.2 mmol·kg-1 dw) med natriumlaktat respektive saltlösnings infusion. Blodglukos, hemoglobin och muskel pH påverkades inte av natriumlaktat infusion. Slutsats: Användande av natriumlaktat infusion som metod under styrketräning kan effektivt användas som verktyg för att höja blod/plasma laktat, och i mindre utsträckning, muskellaktat. Emellertid är samtidig alkalisering av blod en sannolik följd.
Potential sex differences in the molecular response to resistance exercise with lactate infusion
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Ross, James H. "Comparison of blood lactate concentration and perceived exertion during two clinical treadmill protocols." Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1036180.
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The purpose of this study was to determine if previously observed differences in ratings of perceived exertion (RPE) at the same intensities during two graded exercise tests (GXT) were the result of changes in blood lactate concentrations (BLC). Thirteen healthy males (25.3 ±53 yrs.) were maximally tested during two protocols (Bruce and Balke 3.0 mph/2.5 % grade changes every 2 minutes). Subjects were randomly assigned to one GXT and completed the second test after 48 hours; both were completed within one week. Ratings of perceived exertion (RPE) were recorded at the end of each 2 minute stage of the Balke and twice per stage during the Bruce protocol. Blood lactate concentrations (BLC) were collected each minute during both protocols.Results: RPE data was first analyzed using two-way ANOVA (protocol x intensity), and a significant interaction was observed with RPEs being higher at each intensity during the Balke protocol. Mean RPE differences were 1.4, 2.8, and 4.5 for 40, 60, 80% of VO2max respectively. The addition of the BLC at each relative exercise intensity as a covariate in the model suggested that BLC accounted for some of the protocol differences in RPE, at 60 and 80% of VOimax.Conclusion: Differences in RPEs between standard GXT protocols reported in previous studies were due, in part, to differences in BLC.School of Physical Education
13
Socha, Teresa L. "The effects of active and passive recovery on blood lactate concentration and exercise performance following intermittent exercise /." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59863.
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The effects of differing recovery patterns following intermittent exercise on blood lactate and subsequent performance were examined. Fourteen male subjects completed three randomly assigned experimental protocols. Each protocol consisted of eight 45s-bouts of cycling on a Monark cycle ergometer at 120% of VO$ sb2$ max interposed with five minute recovery periods. Each protocol ended with a maximal performance task consisting of a 45s all-out cycling test. Recovery patterns included passive, cycling (45% of VO$ sb2$ max), and arm cranking (45% of VO$ sb2$ max). Results revealed similar blood lactate concentrations in the passive and arm cranking conditions but significantly lower (p $<$.05) levels in the cycling condition. Mean power outputs measured from the performance task were significantly higher (p $<$.05) in the cycling and arm cranking recovery conditions. The correlation between blood lactate levels and mean power output was low (r = $-$0.28), suggesting that other factors were influencing subsequent performance.
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Mavrogiannis, Apostolos. "Variations in the ventilatory and lactate thresholds with prolonged aerobic exercise." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25127.
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The purpose of this study was to examine the changes in the ventilatory (VT) and lactate (LT) thresholds and VO₂max following prolonged aerobic exercise. Six well-trained distance runners (T:age=25.2 yrs, Ht=170.0 cm, Wt=65.0 kg, VO₂max=59.6 ml •kg⁻¹•min⁻¹) and six untrained (UT:age=25.3 yrs, Ht=180.3 cm, Wt=79.2 kg, VO₂max=46.8 ml•kg⁻¹•min⁻¹) males were studied on two occasions seven days apart. The initial evaluation involved a continuous horizontal treadmill test with a starting velocity of 2.22 m•s⁻¹, which was increased by 0.22 m•s⁻¹ each minute until fatigue. Expired gases were continuously sampled and analyzed by a Beckman Metabolic Measurement Cart. Measurements were processed by a data acquisition system (HP 3052A), which determined respiratory gas exchange variables every 15 seconds. Blood lactate measurements were taken via an indwelling catheter during the last 10 sec of each minute of work. VT and LT were determined by visual inspection of the excess CO₂ elimination and lactate curves, respectively. Seven days later the subjects repeated the treadmill test preceded by a 60 minute treadmill run at a heart rate corresponding
to their LT. The physiological measurements recorded during the first session were repeated. There were significant (p<0.10) reductions in VO₂max, LT, VT, and total treadmill time on the VO₂max test (TTT) in the T group (59.6 to 56.9 ml •kg⁻¹•min⁻¹, 9.6 to 9.3 mph , 8.9 to 8.2 mph , and 925.0 to 882.5 sec, respectively). VO₂max, LT, VT, and TTT were reduced in the UT group (46.8 to 45.0 ml•kg⁻¹•min⁻¹ 7.7 to 7.6 mph, 8.0 to 7.2 mph, and 730.0 to 652.5 sec, respectively), however, only VT and TTT were reduced significantly (p<0.10). Although the groups were significantly different (p<0.05) in the initial physiological measures due to training status, there was no change in the rate of decline in VO₂max, LT, VT, or TTT when the UT group was compared to T. As LT and VT are affected by prolonged aerobic exercise it is questionable whether these thresholds can be used with confidence to predict endurance performance in events up to 60 min duration for well-trained and recreational athletes.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
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Sachs, Christina Michelle. "EMG analysis of type IIb muscle fibers correlated with blood lactate accumulation /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418061.
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MIYAMURA, MIHARU, YOSHIHIKO YAMAZAKI, TETSUO OHKUWA, and HIROSHI ITOH. "HUMAN BLOOD LACTATE AND AMMONIA LEVELS AFTER SUPRAMAXIMAL UPHILL AND DOWNHILL RUNNING." Nagoya University School of Medicine, 1996. http://hdl.handle.net/2237/16167.
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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.
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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
18
Catcheside, Peter. "Resting forearm blood-tissue lactate and gas exchange kinetics during supine leg exercise." Title page, contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09PH/09phc357.pdf.
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Bibliography: leaves 230-255. The work described in this thesis was stimulated by the observation that during leg exercise, resting forearm lactate kinetics appear to resemble closely the blood-tissue exchange kinetics of inert gases that have been reported in many organs during inert gas inhalation. Two mathematical models of forearm lactate uptake were developed, and three series of experiments were conducted to investigate the contribution and impact of passive (inert-like) lactate movements to veno-arterial concentration differences in the resting forearm during leg exercise. The results are discussed.
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Aphamis, Georgios. "Lactate and heart rate response during three 400-m training sessions." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=31084.
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Ten trained male track athletes (VO2max = 64.7 ml·kg·min -1) performed three workouts (conditions) with repeated 400-m runs. The intensity and number of repetitions varied among conditions. Condition 1 consisted of two all-out 400-m runs. Condition 2 was 4 x 400-m runs with the first three reps performed 4 s slower than condition 1 and the 4 th rep was all-out. Condition 3 consisted of 8 x 400-m runs with the first seven reps performed 8 s slower than condition 1 and the 8th rep was all-out. Dependent variables were HR, blood lactate and run time for the final rep in each condition. Peak HRs for the last run were 201, 194, 189 beats·min-1 for conditions 1, 2 & 3 respectively, and were not significantly different. Blood lactate values measured 4 min after the last run were 16.6, 17.8 and 17.1 mmol·L -1 in conditions 1, 2 and 3 respectively, and were not significantly different. Run times for conditions 1 (55.2 s), 2 (56.9 s) and 3 (61.5 s) were significantly different (P < 0.05). The decline in performance was greatest in condition 3. The three conditions challenged the anaerobic system with similar peak values for lactate and heart rate during the final run.
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Denton, Jamie. "The kinematic, kinetic and blood lactate profiles of continuous and intra-set rest loading schemes a thesis submitted to the Auckland University of Technology in partial fulfilment of the degree of Master of Health Science, January 2005." Full thesis. Abstract, 2005. http://puka2.aut.ac.nz/ait/theses/DentonJ.pdf.
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Padfield, James. "Physiologic performance characteristics of runners with high and low blood lactate concentrations during maximum steady state /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841179.
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Stark, Ryan M. "Blood lactate threshold determination in elite cross-country skiers on a ski treadmill." Thesis, University of Ottawa (Canada), 1989. http://hdl.handle.net/10393/5633.
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MacKenzie, Mary B. "The relationship between blood lactate and force production in elite cross country skiers." Thesis, University of Ottawa (Canada), 1989. http://hdl.handle.net/10393/5750.
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Koziris, L. Perry (Lymperis Perry). "Blood lactates following intermittent and continuous cycling tests of anaerobic capacity." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60051.
Full textAbstract:
The purpose of this study was to compare the concentration of and the time to peak blood lactate following three 90-s cycle ergometer tests--intermittent all-out (Int-A), continuous all-out (Cont-A), and continuous constant (Cont-C), and to compare group peak lactate to blood lactate at individual peak time. Eight fingertip blood samples were drawn between 1 and 12min post-exercise. Subjects were university hockey players (n = 19) and physical education students (n = 19). The two all-out tests had a higher peak concentration than the Cont-C test (P $<$ 0.05). The Int-A test had an earlier peak than the two continuous tests (P $<$ 0.05) but this difference vanished if peak time was measured from the onset of the tests. A number of sampling times had lactate concentrations similar to the individual peak concentration (P $<$ 0.05): (1) 1, 2, 3, and 4min for Int-A; (2) 2, 3, 4, 5, and 6min for Cont-A; (3) 2 and 4min for Cont-C.
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Forsyth, Jacquelyn Jeanette. "The isolated and combined effects of circadian and circamensal rhythms on blood lactate concentration." Thesis, Liverpool John Moores University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421400.
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Bertram, Sheila Rae. "Blood lactate levels during exercise : the effects of exercise duration, bicarbonate infusion and beta-receptor antagonism." Master's thesis, University of Cape Town, 1985. http://hdl.handle.net/11427/27262.
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This study examines factors that determine blood lactate accumulation during exercise in order to examine the opposing theories that such accumulation occurs either as a result of muscle anaerobiosis or an "overflow" of oxygen-independent glycolysis.
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Regatieri, Inaê Cristina [UNESP]. "Polymorphisms in candidate genes for athletic performance and quantification of MCT1 and CD147 in red blood cells of arabian and quarter horses." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/144477.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O transportador de monocarboxilato isoforma 1 (MCT1), presente na membrana das hemácias, e sua proteína auxiliar CD147 têm como função transportar H+ e lactato do plasma para dentro das hemácias, mantendo assim, a homeostase ácido-base e retardando a acidose sistêmica e fadiga muscular. Dessa forma, o objetivo desse estudo foi comparar as quantidades das proteínas MCT1 e CD147 em hemácias de cavalos Árabes e Quartos de Milha com diferentes níveis de desempenho atlético. Além disso, objetivou-se buscar por polimorfismos para os genes MCT1, CD147, DMRT3 e PDK4, a fim de checar associações entre os polimorfismos e o desempenho nas raças. Cavalos Árabes e Quartos de Milha foram divididos em dois grupos de acordo com o desempenho em provas de enduro e provas de corridas, respectivamente. A quantidade de MCT1 e CD147 na membrana plasmática das hemácias foi determinada por western blotting com unidades arbitrárias de densidade óptica (OD) e anticorpos reagentes à espécie humana anti-MCT1 e anti-CD147. Os dados para as quantidades de proteínas foram analisados pelo PROC MIXED do SAS. O modelo incluiu a idade como covariável e os efeitos fixos de sexo, raça e grupo de desempenho dentro de raça. As correlações foram analisadas pelo teste de Pearson pelo procedimento PROC CORR. P-valores <0,01 foram considerados estatisticamente significantes. Os polimorfismos dos genes foram analisados por sequenciamento (MCT1 e CD147), PCR-RFLP (DMRT3) e ARMS-PCR (PDK4). Os pacotes estatísticos Genetics, Lattice e GenABEL foram utilizados para comparar as frequências dos grupos de desempenho no software R, com o teste exato de Fisher a 5% de significância. As proteínas MCT1 e CD147 foram encontradas nas hemácias de todos os animais. A quantidade de MCT1 foi significativamente (p<0,0001) maior em Quartos de Milha (2,99 ± 0,35 OD) do que em Árabes (1,04 ± 0,08 OD). Quartos de Milha (3,23 ± 0,38 OD) também apresentaram maior conteúdo de CD147 do que Árabes (0,88 ± 0,06 OD). Não houve diferença estatística nas quantidades de proteínas para os grupos de desempenho de ambas as raças. Correlação positiva foi encontrada entre as quantidades de MCT1 e CD147 (r=0,95; p<0,0001). O Alelo A dos polimorfismos Lys457Gln:1573A>C do gene MCT1 e Ile51Val:168A>G do gene CD147 estavam fixados em ambas as raças. Um novo polimorfismo (AY457175.1:c1498G>A) foi encontrado na sequência do gene MCT1. Para o DMRT3, todos os animais apresentaram o alelo C fixado para o polimorfismo. Árabes mostraram maior frequência para o alelo G do que Quartos de Milha (p<0,01) para o polimorfismo no gene PDK4. Entretanto, não houve diferença entre os grupos de desempenho para as duas raças. Dessa forma, conclui-se que Quartos de Milha têm maiores quantidades de MCT1 e CD147 do que Árabes. Não foi possível determinar a influência dos polimorfismos nos genes MCT1, CD147 e DMRT3 no desempenho atlético das duas raças visto que seus alelos estavam fixados. Além disso, houve diferença significativa nas frequências do polimorfismo no gene PDK4 entre Árabes e Quartos de Milha, mas não houve diferença entre os grupos de desempenho.
Monocarboxylate transporter isoform 1 (MCT1), present in the red blood cell membranes and its ancillary protein CD147 have as function transport H+ and lactate ions from the plasma into the red blood cells, thereby maintaining acid/base homeostasis and retarding systemic acidosis and muscular fatigue. Thereby, the aim of this study was to compare the amount of MCT1 and CD147 proteins in the red blood cells of Arabian and Quarter Horses with different levels of athletic ability. Furthermore, we investigated polymorphisms for MCT1, CD147, DMRT3, and PDK4 genes in Arabian and Quarter Horses in order to check associations between the polymorphisms and the performance in these breeds. Arabian horses were divided into two groups according to their performance in endurance competition and Quarter Horses were separated by its performance in races, determined by Speed Index. The amount of MCT1 and CD147 proteins in the plasma membrane of red blood cells was determined by western blotting analysis with arbitrary optical density units (OD), using a human specific anti-MCT1 and anti- CD147 antibody. Data for the amounts of proteins were analyzed using the PROC MIXED procedure of SAS software. The model for the analysis included the effects of sex, breed and performance group within breed as fixed effect and age as covariate. The correlations were analyzed by Pearson correlation test using the PROC CORR procedure of SAS software. P values <0.01 were considered statistically significant. Polymorphisms of the genes were analyzed by sequencing (MCT1 and CD147), PCR-RFLP (DMRT3) and ARMS-PCR (PDK4) techniques. The statistical packages Genetics, Lattice and GenABEL were used to compare the frequencies of the groups using the software R, with the Fisher's exact test being performed with significance level of 5%. MCT1 and CD147 proteins were found in the red blood cell membranes of all studied animals. The amount of MCT1 was significantly (p<0.0001) higher in Quarter Horses (2.99 ± 0.35 OD) than in Arabians (1.04 ± 0.08 OD). Quarter Horses (3.23 ± 0.38 OD) also showed bigger contents of CD147 than Arabians (0.88 ± 0.06 OD). There was not statistical difference in the amounts of MCT1 and CD147 between the performance groups of both breeds. Positive correlation was found between the amounts of MCT1 and CD147 (r=0.95; p<0.0001). The A allele from the polymorphisms Lys457Gln:1573A>C of MCT1 and Ile51Val:168A>G of CD147 gene, were fixed in both breeds. A new polymorphism (AY457175.1:c1498G>A) was found in the MCT1 gene sequence. For DMRT3 mutation, all the animals shown to have the C allele fixed for the polymorphism. Arabians showed significant greater frequency of the G allele than Quarter Horses (p<0.01) for the PDK4 polymorphism. However, there was not difference between the groups of performance for both breeds. In summary, it follows that the Quarter Horses have greater amount of MCT1 and CD147 proteins than Arabian. It was not possible to determine the influence of polymorphisms in MCT1, CD147 and DMRT3 genes in the athletic performance of these breeds since they had alleles fixed. There was a significant difference in the frequencies of the PDK4 polymorphism between Arabians and Quarter Horses, but there was not difference between the performance groups.
FAPESP: 2012/24193-0
FAPESP: 2012/20697-9
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Weber, Jean-Michel. "Lactate turnover in fast-moving vertebrates : the control of plasma metabolite fluxes." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27561.
Full textAbstract:
During sustained exercise, working muscles must be
supplied with adequate kinds and amounts of exogenous fuels,
and the delivery rates of oxygen and oxidizable substrates
should be matched. The study of metabolite fluxes and their
regulation is therefore critical to the understanding of
exercise metabolism. Lactate has received renewed attention
from physiologists and biochemists with the realization that
it is not only an end product of glycolysis, but also an
important fuel for aerobic work. As an oxidizable fuel, this
substrate may provide some performance advantage over other
fuels such as glucose and free fatty acids. The goals of this
thesis were: 1) to determine whether endurance-adapted
animals can support higher plasma lactate turnover rates than
sedentary animals; and 2) to investigate the major factors
involved in the regulation of plasma metabolite turnover at
the whole-organism level - using lactate as a model. Lactate
turnover rates were measured by bolus injection of [U-¹⁴C]lactate in skipjack tuna, Katsuwonus pelamis, and in thoroughbred racehorses, Equus caballus. In tuna, turnover rates ranged from 112 to 431 umol min⁻¹ kg⁻¹ and they were positively correlated with lactate concentration (slope = 15.1, r = 0.92). This teleost is able to support higher plasma lactate turnover rates than expected for a mammalian lower temperature, and lactate is probably an important oxidizable fuel in this species. For comparative purposes, resting turnover rates of lactate and glucose were plotted versus body mass on a log-log scale for a wide range of mammalian species. These plots were linear, and they showed the same slope as the classic body mass vs metabolic rate relationship.
Thoroughbred horses are likely to have an aerobic
scope of 40-fold or more. One of their main physiological
adaptations to exercise is the ability to increase hematocrit
by more than one and a half-fold in response to exercise. In
the present study, this adjustment allowed them to reach an
A-V difference in 0₂ content of more than 23 vol% during
maximal exercise, a much higher value than other mammals.
Their lactate turnover rate and cardiac output were measured
at rest and two levels of submaximal exercise (45 and 55
V0₂ max) to investigate the relationship between
cardiovascular adjustments on plasma lactate turnover rate.
Cardiac output ranged from 106 to 571 ml min⁻¹ kg⁻¹, and
mean lactate turnover rate from 9.3 at rest, to 75.9 umol min⁻¹ kg⁻¹ at 55% V0₂ max. In contrast with the situation found in tuna, the lactate turnover rates of thoroughbreds were not elevated compared with other mammals, showing that the metabolic adaptations of these outstanding athletes do not include the ability to sustain higher lactate fluxes than sedentary animals. In horses, the contribution of plasma lactate oxidation to V0₂ is minimal, and this substrate is not an important oxidative fuel; lipid oxidation may represent their major pathway for aerobic energy production during exercise. The ability to oxidize plasma lactate at high rates is therefore not necessarily required for the "elite" performance of endurance exercise. This study also shows that both, plasma lactate concentration and cardiac output are positively correlated with turnover rate. The correlation between cardiac output and lactate turnover rate is independent of the relationship between plasma lactate concentration and turnover rate. Plasma metabolite concentration and cardiac output can be regulators of plasma metabolite turnover rate. It is proposed that these two variables are, respectively, the fine and coarse controls for flux rate adjustments during exercise.Science, Faculty of
Zoology, Department of
Graduate
29
Coffer, Larry W. II Greenwood Mike. "The effects of active and passive recovery on blood lactate in collegiate female tennis players." Waco, Tex. : Baylor University, 2006. http://hdl.handle.net/2104/5013.
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Nemeth, Peter M. D. "Venous blood lactate responses to forearm exercise in the diagnosis of chronic fatigue syndrome (CFS) /." Title page and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09S.B/09s.bn433.pdf.
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Fischer, Karin Christine. "The influence of submaximal blood lactate measures on VOb2smax estimates using a submaximal branching protocol." Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1014857.
Full textAbstract:
The purpose of this study was to examine if measurements of submaximal blood lactate may improve the prediction of VO2max from submaximal exercise tests. Subjects (39 men & 21 women, age 20-44 yrs) completed a branching protocol on a cycle ergometer which consisted of 3 submaximal stages of 4 minutes each followed by a maximal effort. During the last minute of each stage heart rate (HR) was recorded from telemetry and a capillary blood sample was obtained from a finger puncture. Maximal power output was estimated from the extrapolation of the 3 submaximal HRs to age predicted HRmax and blood lactate concentration was measured using a Yellow Springs analyzer (Yellow Springs, OH). Data were analyzed using multiple regression procedures. Estimated maximal power output (238 ± 56 W) was significantly related to measured VOzmaX (p < 0.001, r2= .523). Mean values for ACSM estimated, ACSM-revised and measured VOz.X were not significantly different (3.170 vs. 3.140 vs. 3.260 L/min respectively), however the SEE % for the ACSM and ACSM revised estimated VOz,. were 13.4% and 12.1%, respectively. When the change in power output relative to the change in blood lactate concentrations (po/BL) from stage 1 to stage 2 and the estimated maximal power output from 3 submaximal heart rates were added as independent variables to the regression model with measured VO2,t as the dependent variable, po/BL was significantly correlated with VO X , accounting for 7.6% of the variance in VOz... In conclusion, only the relative change in power output to the relative change in blood lactate measure from stage 1 to _2 were significant in improving the estimation of VO2 during submaximal exercise tests using a branching protocol. Other blood lactate measures did not improve the estimation of VOA,. in this study.School of Physical Education
32
Mancini, Wendy F. "Power output and lactate concentration following repeated 10 s intervals using varying recovery patterns." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61140.
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Blood lactate concentration and mean power output were examined over a series of maximal intermittent exercise bouts with varying recovery patterns. Thirteen elite male cyclists completed four randomly assigned experimental conditions. Each exercise/recovery condition consisted of twelve 10 s maximal exercise bouts on a Monark cycle ergometer. Four different recovery patterns (30, 60, 90 and 120 s) followed the repeated 10 s all-out efforts. Results revealed that the mean power output averaged over the 12 trials was 12.7, 13.0, 13.2 and 13.4 W/kg, for the 30, 60, 90 and 120 s conditions, respectively. Blood lactate concentration during exercise were 9.9, 9.2, 6.5 and 6.0 mmol/1, for the 30, 60, 90 and 120 s conditions, respectively. The 30 and 60 s conditions yielded significantly lower mean power output values compared to the 90 and 120 s conditions. Following the repeated maximal 10 s efforts, blood lactate concentration was significantly greater in the 30 and 60 s recovery conditions compared to the 90 and 120 s conditions.
33
Williams, Donna Ann. "RELATIONSHIP BETWEEN PLASMA VOLUME AND BLOOD LACTATE DURING EXERCISE FOLLOWING SIMULATED WEIGHTLESSNESS (BEDREST DECONDITIONING, ANAEROBIC THRESHOLD)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275469.
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Drummond, Micah J. "The influence of controlled frequency breathing on blood lactate levels during graded front crawl stroke swimming." Scholarly Commons, 2001. https://scholarlycommons.pacific.edu/uop_etds/552.
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Controlled frequency breathing (CFB) is a training technique used by swimmers in an effort to limit oxygen availability to the body and stimulate anaerobic metabolism. During CFB, a swimmer restricts breathing to one breath every six, seven, or even eight strokes per breath. The purpose of this study was to determine tb.e influen<;:e of CFB on blood lactate, heart rate, and stroke rate during front crawl stroke swimming. A maximal exertion test was used to determine peak swimming velocity. Based on this maximal test, five different workloads were used to compare CFB and normal breathing (NB). Subjects swam three-minute workloads at 55%,65%,75%, 85%, and 95% of maximal effort with two minutes rest between each workload. Blood lactate and heart rate were measured immediately after each workload and stroke rate was counted manually. Subjects were assigned to breathe normally (NB) or to restrict their breathing to one breath every eight strokes (CFB). Breathing conditions were randomly assigned. Multivariate analysis was used to compare the blood lactate, heart rate, and stroke rate between NB and CFB. Tukey's post hoc test was used when F-values were significant (p<0.05). Twenty-eight subjects (18 females, 10 males) completed the entire protocol. As expected there were significant main effects for the heart rate and blood lactate responses to increasing workloads (p<0.01). However, CFB did not alter blood lactate levels when compared to NB. Interestingly, heart rate (p=0.014) was lower and stroke rate (p=0.011) was higher in the CFB condition when compared to N'B.
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SAKAMOTO, NOBUO, TATSUAKI MATSUBARA, and KYOJI KATO. "Correlation between Myocardial Blood Flow and Tissue Succinate during Acute Ischemia." Nagoya University School of Medicine, 1994. http://hdl.handle.net/2237/15937.
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Buffone, Michael A. "Blood lactate response and performance in a simulated ice hockey task in male varsity and recreational players." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0002/MQ43840.pdf.
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Lu, Shin-Shan. "The effects of active and passive recovery on blood lactate concentration and exercise performance in cycling tests /." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60011.
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The purpose of this study was to examine the effects of recovery modes and exercise durations on blood lactate concentrations and subsequent performance in cycling tests. Fourteen male subjects completed six randomly assigned experimental protocols with a combination of three durations and two modes of recovery (passive and active cycling at 45% VO$ sb{ rm 2 max}$). Each protocol consisted of eight bouts of cycling at 120% of VO$ sb{ rm 2 max}$ interspersed with five minute recovery periods. Each protocol terminated with a maximal performance task consisting of a 45s all-out cycling test. Results indicated significantly (p $<$ 0.05) higher blood lactate concentrations in the passive and 60s conditions. Mean power outputs measured in the performance task were significantly (p $<$ 0.05) higher in the active recovery conditions compared to passive recovery. Mean power outputs were lower during the 60s conditions. Since the correlation between blood lactate and mean power output was low (r = -0.24), other factors were influencing subsequent performance.
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Osborne, Mark. "The Slow Component of O2 Uptake Kinetics : the Relationship Between Blood Lactate, pH and Motor Unit Recruitment." Thesis, Griffith University, 2009. http://hdl.handle.net/10072/365879.
Full textAbstract:
The primary aim of this thesis was to develop a better understanding of the physiological mechanisms that cause the slow rise in O2 uptake (V•O2) that occurs during heavy- and severe-intensity exercise. The slow rise in V•O2 during heavy-intensity exercise is known as the slow component of O2 uptake kinetics. This thesis includes a series of three studies investigating the mechanisms underlying the elevated O2 cost observed during heavy-intensity constant-load cycling exercise. Eight recreational cyclists (V•O2peak: 55.6 ± 1.3 ml•kg-1•min-1) participated in each of the three studies. Each study was designed to manipulate blood lactate concentration ([La-]) and/or blood pH, or type II motor unit recruitment to determine if a corresponding change would occur in the amplitude of the V•O2 slow component. All studies used a similar research design with each trial involving 3 minutes of baseline cycling (25 W) prior to 8 minutes of heavy-intensity constant-load cycling at a power output equal to 50% of the difference between the power output achieved at the ventilatory threshold and peak aerobic power (Δ50% work rate). Surface electromyographic (EMG) activity from the vastus medialis and vastus lateralis was measured throughout each constant-load cycling trial. Integrated EMG activity was used as an index of total neural activity, while the mean power frequency of the EMG signal was used as an indication of motor unit recruitment pattern. Blood lactate, pH and bicarbonate concentrations were determined under resting conditions prior to the start of exercise, at the end of 3 minutes at 25 W, and after 1.5, 3, 4.5, 6 and 8 minutes of heavy-intensity constant-load exercise. O2 uptake, CO2 production (V•CO2), and minute ventilation (V•E) were measured breath-by-breath while heart rate was measured continually throughout each constant-load trial. V•O2 kinetics were determined using a double-exponential model with independent time delays beyond the phase I component.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Physiotherapy and Exercise Science.
Griffith Health
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Vogler, Andrew James, and avogler@virginbroadband com au. "Field based testing protocols to monitor training adaptations and performance in elite rowers." Flinders University. Education, 2010. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20100302.133001.
Full textAbstract:
Laboratory-based rowing tests are the established standard for assessing fitness traits among elite rowers, and for prescribing individualised exercise intensities for training. But because tests occur on a rowing ergometer, the specificity of laboratory testing has been questioned compared with the criterion of on-water rowing. This project validated equipment required to replicate a laboratory-based rowing test in the field and evaluated the feasibility of on-water tests. Ergometer and on-water test results were compared to assess the validity of ergometer-derived training prescriptions and to establish the effectiveness of on-water tests for monitoring longitudinal fitness changes and for predicting rowing performance.
Concept2 rowing ergometers (Morrisville, USA) have frequently been used for rowing tests. Although subtle design variations exist between the different models of Concept2 ergometer, there were no substantial differences between the results from incremental rowing tests using Model C and Model D ergometers. The Concept2 Model D was therefore accepted as the standard ergometer for subsequent laboratory tests. Typical error (TE) results from duplicate Concept2 Model D tests conducted 2-4 d apart showed that laboratory tests were highly reliable (TE: maximal power = 2.8%, peak oxygen consumption = 2.5%).
As oxygen consumption (VO2) is measured routinely during laboratory rowing tests, it is necessary to obtain similar measurements during any on-water protocol. The MetaMax 3B portable indirect calorimetry system (Cortex, Leipzig, Germany) was therefore validated against a first-principles, laboratory-based indirect calorimetry system (MOUSe, Australian Institute of Sport, Canberra, Australia). VO2 from the MetaMax was significantly higher during submaximal exercise (p=0.03), although results were within 0.16 L.min-1 (4.1%) across all exercise intensities. There was good agreement between duplicate MetaMax trials separated by ~2 d; mean VO2 was within 0.11 L.min-1 (2.5%) and TE was ¡Ü2.3%.
The specificity of rowing testing was improved using an On-water incremental test that replicated a laboratory-based Ergometer protocol. However, the individual variation in physiological responses between-tests meant that training intensity recommendations from the Ergometer test were not always applicable to on-water training. Furthermore, measurements from the On-water protocol displayed similar or lesser reliability (TE=1.9-19.2%) compared with the Ergometer test (TE=0.1-11.0%).
As an effective fitness test must also be sensitive to longitudinal changes, the responses to 6 wks training were compared between the Ergometer and On-water methods. The magnitude of On-water training effects were usually greater (small Cohen¡¯s effect size) compared with the Ergometer test (trivial effect), although On-water and Ergometer tests both indicated that training responses were negligible because virtually all changes were less than one of their respective TEs. Correlations between test results and rowing performance were largest when rowing mode was matched between conditions, but Ergometer results provided the highest correlations (Ergometer vs. 2000-m ergometer time-trial: R= -0.92 to -0.97 compared with On-water vs. On-water maximal power output: R=0.52 to 0.92).
Although On-water tests improved the specificity of on-water training prescriptions, these tests provided no obvious benefits for monitoring longitudinal fitness changes or performance compared with Ergometer tests. Given that On-water tests are also more time consuming and logistically challenging, their practical application is limited.
40
Kaczynski, Marek. "The effects of active and passive recovery on blood lactate concentration and performance in a simulated ice hockey task /." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61826.
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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
42
Pennell, Craig Edward. "The role of lactate measurement in the prediction of fetal hypoxic-ischaemic brain injury during labour." University of Western Australia. School of Women's and Infants' Health, 2004. http://theses.library.uwa.edu.au/adt-WU2003.0037.
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[Truncated abstract] In this thesis the role of lactate measurement has been evaluated in intrapartum assessment of fetal wellbeing. Specifically, I have addressed the question of whether fetal lactate measurement is better than the assessment of fetal heart rate patterns or the measurement of pH at predicting fetal brain injury after intrapartum asphyxia. Using an ovine model of repeated umbilical cord occlusion designed to mimic events which may occur during human labour, I have shown that the measurement of fetal lactate levels after repeated cord occlusion is significantly associated with the severity of brain injury after the asphyxial insult. No significant associations were identified with fetal pH measurements or with the duration of decelerative or compound fetal heart rate patterns; however, this is the first study to describe an association between the duration of both increased fetal heart rate variability and fetal heart rate overshoot with the severity of subsequent brain injury. Although no significant association was identified between fetal arterial pressure measured between umbilical cord occlusions and the grade of brain injury, the studies performed in this thesis are the first to show a strong correlation between the duration of specific arterial pressure responses during cord occlusions and the grade of brain injury, accounting for approximately 90% of the variability seen in the severity of injury. The mechanism responsible for the improved ability of lactate measurement to predict fetal brain injury is unknown. It may be because fetal lactate levels are a more stable marker of anaerobic metabolism of glucose than fetal pH levels, which are influenced by both increasing levels of carbon dioxide and anaerobic metabolism of amino-acids and fatty acids. In addition fetal pH levels can be rapidly normalised through placental exchange of carbon dioxide whereas fetal lactate levels are slow to normalise across the placenta as they rely on facilitated diffusion.
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Matheson, Gordon Omar. "The effect of breath-holding during intense intermittent exercise on arterial blood gases, acid-base balance, and lactate." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26354.
Full textAbstract:
Eight healthy female volunteers (mean age 24.4 ± 3.4) served as subjects in an experiment measuring acid-base and lactate changes while breath-holding during intense, intermittent exercise. The subjects were
endurance trained (VO₂[sub max] = 56.8 ± 3.9 ml'kg-min⁻¹) with normal resting
pulmonary function. Utilizing a counterbalance design, each subject repeated
5 intervals of a 15 second treadmill run at 125 % VO₂[sub max], once while
breath-holding (BH), and once while breathing freely (NBH). Blood samples at rest, at the end of each work and rest interval, and throughout recovery were taken from a teflon catheter inserted in the radial artery. Samples were
analyzed for pH, PaO₂, PaCO₂, SO₂, bicarbonate, and lactate. The results
were analyzed using repeated measures ANOVA to compare BH with NBH. Significant (p≤.01), reductions were found in pH associated with significant
elevations in PaCO₂ and HCO₃- at the end of each 15 sec exercise interval in
the BH condition. These changes did not persist throughout the rest intervals
(p>.05). In addition, significant (p≤.01), drops in PaO₂ and SaO₂ were found at
the end of each exercise interval in the BH condition that were not found at the end of each rest interval. Significantly increased rates of lactate appearance in the arterial blood were found during recovery in the BH conditon. It was concluded that breath-holding during intense, intermittent exercise produced acid-base changes greater than those seen at similar exercise intensities while breathing. In addition, breath-holding during intense, intermittent exercise produces significant hypoxia. The significantly increased rates of lactate appearance during recovery in the BH condition are most likely due to increased tissue anaerobiosis.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
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Barnett, Christopher. "The effect of L-carnitine supplementation on blood and muscle lactate accumulation during high intensity sprint cycling exercise." Virtual Press, 1993. http://liblink.bsu.edu/uhtbin/catkey/865941.
Full textAbstract:
This study examined the effects of 14 days of L-carnitine supplementation on blood and muscle lactate concentrations, and carnitine fractions, during high intensity sprint cycling exercise. Eight subjects performed three experimental trials - control I (CON I, 0 days), control II (CON II, 14 days), and L-carnitine (LCN, 28 days). Each trial consisted of a 4 min ride at 90% VO2max, followed by a rest period of 20 min, and then 5 x 1 min rides at 115% VO2max (2 min restbetween each). Following CON II, all subjects began dietary supplementation of L-carnitine for a period of 14 days (4 g/day). L-carnitine supplementation had no significant effect on either muscle carnitine or lactate concentrations following the 4 min 90% ride. Plasma total acid soluable and free carnitine concentrations were significantly higher at all time points following supplementation. Differences observed in blood hydrogen ion and lactate concentrations between CON I and CON II appear to be the result of an order effect. The data from the present investigation indicate that L-carnitine supplementation has no significant effect on blood or muscle lactate accumulation following high intensity sprint cycling exercise.School of Physical Education
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Williams, Wendy Ann 1960. "Changes in blood parameters, muscle myoglobin and muscle lactate dehydrogenase of the Common Murre (Uria aalge) during maturation." Thesis, Thesis (M.S.)--University of Oregon, 1992, 1992. http://hdl.handle.net/1794/9933.
Full textAbstract:
Typescript.
Includes vita and abstract.
Bibliography: Includes bibliographical references (leaves 95-99).
Description: xii, 99 leaves : ill. ; 29 cm.Blood oxygen carrying capacity, myoglobin levels and LDH isozyme compositions in the heart, gastrocnemius and pectoralis muscles were determined in Common Murre adults and during maturation of the chick at sea. Oxygen stores in the chick (hemoglobin, hematocrit, muscle myoglobin) increased significantly with growth. High levels of the aerobic isozyme, LDH 1, were maintained throughout maturation in the heart. All five LDH isozymes were maintained at similar levels in the gastrocnemius muscle. The pectoralis showed an increase in LDH 1, 2, 3, and 4, yet retained relatively high levels of LDH 5 throughout maturation. Upon leaving the nesting colony, metabolic capacities in the heart and gastrocnemius of the chick are similar to those of adults. The chick pectoralis tissue, however, gains aerobic capacities with maturation which is concomitant with the needed capacity for aerial and aquatic flight upon fledging.
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Paknys, Darius. "Laktato ir vegetacinių sistemų rodiklių kaita kartotinio sunkėjančio krūvio metu." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2005. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2005~D_20050519_082828-42801.
Full textAbstract:
Alternation of indicators of lactate and vegetative systems during heightening of load.
Purpose of the investigation was to compare alternation of vegetative systems indicators and blood lactate concentrations and during iterative load heightening.
Tasks of the investigation: to compare alternation of vegetative systems indicators during replacement and recovery under different loads in respect of lactate threshold.
Eight young healthy males took part in the investigation. Average age of subjects was 21,7 years. Investigation was carried out in Laboratory of Sports Physiology of Lithuania Physical Education Academy. Every subjects has undergone two different investigations: working with veloergometer. One –interval increasing load (3 min of work and 3 min of rest), mill-pedalling frequency – 70 times per minute; the other one – continuous increasing load until subject’s inability to maintain required pedalling frequency. The first load was 70 W. Capillary blood sampling was done from finger at the end of the third min of each load during interval test.
While doing continuous increasing load subjects after the warming-up (5 min of work with 50 W of capacity) with the help of the veloergemeter produced continuous load that was heightened by 21 W every minute. Wheeling frequency was 70 times per minute. Starting load was 70 W. Load was continuously heightened until the fatigue, i.e. until the subject was able to take a new load for one minute. During the whole investigation and... [to full text]
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Campos, Fábio Angioluci Diniz. "Demanda energética em situação simulada de luta em atletas de taekwondo." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/39/39134/tde-03112011-083727/.
Full textAbstract:
O objetivo deste estudo foi investigar as contribuições dos sistemas energéticos e do gasto energético total em situação de luta. A amostra foi composta de 10 atletas do sexo masculino de nível nacional/internacional (21±6 anos; 176.2±5.3cm; 67.2±9.0kg), competindo em nível internacional. Para a estimativa das contribuições energéticas e do gasto energético total, foram realizados três protocolos simulando combate (um round, dois rounds e três rounds). As lutas foram filmadas para quantificação das ações motoras em cada round. A estimativa dos sistemas energéticos aeróbio (WAER), anaeróbio alático (WPCR) e anaeróbio lático (W[La-]) foi realizada através do consumo de oxigênio durante a atividade, do delta da concentração sanguínea de lactato de cada round e do débito alático de oxigênio (DAO2), respectivamente. A razão entre as ações de elevada intensidade e momentos de baixa intensidade (step e pausa) no protocolo 3 foi ~1:7. Os resultados dos sistemas WAER, WPCR e W[La-] no protocolo 3 foi 120±22kJ (66±6%), 54±21kJ (30±6%), 8,5kJ (4±2%), respectivamente. Assim, as sessões de treinamento devem ser direcionadas principalmente para a melhoria do sistema anaeróbio alático (responsável pelas ações de alta intensidade), e do sistema aeróbio (responsável pelo processo de recuperação entre as ações de alta intensidade)The purpose of this study was to investigate energy system contributions and energy cost in combat situation. The sample was constituted by 10 male taekwondo athletes at national/international level (age: 21±6 years old; height: 176.2±5.3cm; body mass: 67.2±9.0kg) competing at national/international level. To estimate the energy contributions and total energy cost of the fights, athletes performed a three different protocols simulated competition (1 round, 2 rounds and 3 rounds). The combats were filmed in order to quantify the actual time spent fighting in each round. The estimate of the aerobic (WAER), anaerobic alactic (WPCR) and anaerobic lactic (W[La-]) energy systems was carried out through the oxygen consumption during the activity, the fast component of excess post-exercise oxygen consumption, and the delta of blood lactate concentration in each round, respectively. The mean data between the high intensity actions and moments of low intensity (step and pause) was ~1:7. The results of WAER, WPCR and W[La-] system contributions were 120±22kJ (66±6%), 54±21kJ (30±6%), 8,5kJ (4±2%), respectively. Thus, training sessions should be directed mainly to the improvement of the anaerobic alactic system (responsible by the high-intensity actions), and of the aerobic system (responsible by the recovery process between high-intensity)
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Chae, Sungwon. "Acute Endocrine Responses to Rest Redistribution with Heavier Loads in Resistance-Trained Men." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1707275/.
Full textAbstract:
The purpose of this study was to investigate endocrine responses to redistribution with heavier loads (RR+L) during back squat (BS) exercise in resistance-trained men. Ten men (mean±SE; 23±2 years, 175.6±2.0 cm, 78.0±3.4 kg, 4±1 training years) were assigned using randomization to either RR+L (4 sets of (2×5 repetitions) of BS with 30 s intra-set and 90 s inter-set rest using 75% of their 1RM) or traditional sets (TS; 4 sets of 10 repetitions of BS with 120 s inter-set rest using 70% of their 1RM). Fasted blood samples were collected pre-exercise (PRE), immediately post-exercise (IP), and 5 (+5), 15 (+15), and 30 (+30) minutes post-exercise to analyze the concentrations of testosterone (T), growth hormone (GH), cortisol (C), and blood lactate (BL). Two-way ANOVAs with repeated measures were used (p≤0.05). A main effect of condition (p=0.023) was observed for BL (RR+L; 5.9±0.5 vs TS; 6.7±0.4 mmol/L). A main effect of time point (p≤0.001) was observed for T, GH, C, and BL. T was greater at IP (8.8±1.1), +5 (9.0±1.1), +15 (8.5±1.0), and +30 (8.0±1.0) than PRE (7.1±0.8 ng/mL). GH was greater at IP (58.3±12.7), +5 (62.8±12.7), +15 (67.9±13.3), and +30 (52.8±11.2) than PRE (3.6±1.6 µIU/mL). C was greater at +15 (25.5±2.9) and +30 (25.6±2.7) than PRE (20.0±2.7 µg/dL). BL was greater at IP (8.6±0.6), +5 (8.2±0.6), +15 (7.4±0.5), and +30 (5.8±0.5) than PRE (1.4±0.2 mmol/L). RR+L resulted in lower BL but no differences in T, GH, and C responses compared to TS. Thus, practitioners may incorporate RR+L without affecting endocrine responses.
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Williams, Joanne Ruth. "The blood lactate response to exercise in children aged 11 to 16 years with reference to cardiorespiratory variables, chronological age, sex, sexual maturity & habitual physical activity." Thesis, University of Exeter, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278304.
Full text
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Seburn, Kevin L. "The effect of the manipulation of blood lactate on the integrated EMG of the vastus lateralis muscle during incremental exercise." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28539.
Full textAbstract:
This study was designed to test the hypothesis that the electromyographic signal recorded from a working muscle reflects changes in blood lactate concentrations.
A group of trained cyclists performed two incremental exercise tests on a cycle ergometer. The Control Trial was a incremental test with power increments of 23.5 watts per minute. Cadence was monitored and maintained at 90+/-1 revolutions per minute. The Experimental Trial consisted of a high intensity arm exercise protocol designed to elevate blood lactate above 8 mmol/1. The arm protocol was followed by five minutes of rest and the incremental exercise protocol used in the Control Trial.
Expired gases were sampled every fifteen seconds and calculated values for oxygen uptake, ventilation, excess CO₂, and R.Q. were averaged to give a mean value for each minute in both trials. Heart rate was monitored and recorded every minute for both trials.
Electromyographic data were sampled from the vastus lateralis of the right leg for the final eight seconds of each workload in both trials. The data were integrated for each pedal cycle and averaged to give a mean integrated value for each cycle (CIEMG) for each workload.
During both trials blood samples were drawn from the cephalic vein of the left arm during the last ten seconds of each workload. The anaerobic threshold (Tlac) was determined using the log-log transformation as outlined by Beaver et al., (1985).
Control Trial lactate concentration showed a marked inflection point after an initial slow increase. The mean maximal lactate concentration was 18.21 +/- 5.54 in the Control Trials. This inflection point occurred at a mean lactate concentration of 5.58 +/- 1.05 mmol/1. The mean oxygen uptake at the inflection point was 2.28 +/- 0.37 1/min which represented a mean of 72.6 +/- 7.20 % of maximum. Experimental Trial mean plasma lactate at the beginning of incremental exercise was 26.61 +/- 8.86 mmol/1. The plasma lactate concentration decreased steadily for the initial loads to a mean low concentration of 10.78 +/- 5.78 mmol/1 at Tlac and then increased to a mean of 19.08 +/- 6.66 mmol/1 at test completion. Plasma lactate concentration was greater in the Experimental Trial at all workloads though the values tended to converge once Tlac was surpassed.
No visually identifiable inflection point in the plot of CIEMG vs Power could be determined in any of the plots. An analysis of the slope of the CIEMG vs. Power relationship was therefore performed. An analysis of variance demonstrated no significant difference in the slope of the relationship within or between trials in three different comparisons. The slope of the line was not statistically different when compared over: (a) the entire sample (b) pre Tlac and (c) post Tlac. Correlations performed between plasma lactate concentrations and CIEMG were significant in five of six subjects during the Control Trial (r = 0.57 to 0.97). During the Experimental Trial only three of the six subjects showed significant correlations and they were in the opposite direction (r = -0.62 to -0.96). Correlations between power output and CIEMG were for all subjects in both trials (r = 0.92 to 0.99 Control, r = 0.91 to 0.99 Experimental).
The increase seen in CIEMG with increased power output reflects poorly the changes in blood lactate concentrations under the conditions of this investigation. Plasma lactate showed a dramatic increase in the Control Trial and a steady decrease from an initial high concentration followed by a marked increase in the final workloads of the Experimental Trial. In contrast the CIEMG increased in a near linear fashion for all subjects in both trials. The changes in CIEMG showed highly significant correlations with changes in VO₂ or power output in both trials for all subjects. These results indicate that changes in the surface electromyogram are highly related to changes in power output. However the surface electromyogram changes are not driven by changes in lactate concentration under the conditions of this investigation and may not be a sensitive enough indicator of these changes to be employed in the determination of Tlac.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate