Effects of Lactate Consumption on Blood Bicarbonate Levels and Performance During High-Intensity Exercise

The authors sought to determine the effects of oral lactate consumption on blood bicarbonate (HCO3−) levels, pH levels, and performance during high-intensity exercise on a cycle ergometer. Subjects (N = 11) were trained male and female cyclists. Time to exhaustion (TTE) and total work were measured during high-intensity exercise bouts 80 min after the consumption of 120 mg/kg body mass of lactate (L), an equal volume of placebo (PL), or no treatment (NT). Blood HCO3− increased significantly after ingestion of lactate (p < .05) but was not affected in PL or NT (p > .05). No changes in pH were observed as a result of treatment. TTE and total work during the performance test increased significantly by 17% in L compared with PL and NT (p = .02). No significant differences in TTE and total work were seen between the PL and NT protocols (p = .85). The authors conclude that consuming 120 mg/kg body mass of lactate increases HCO3− levels and increases exercise performance during high-intensity cycling ergometry to exhaustion.

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The influence of whole-body vs. torso pre-cooling on physiological strain and performance of high-intensity exercise in the heat

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology ◽

10.1016/s1095-6433(01)00272-0 ◽

2001 ◽

Vol 128 (4) ◽

pp. 657-666 ◽

Cited By ~ 41

Author(s):

G.G. Sleivert ◽

J.D. Cotter ◽

W.S. Roberts ◽

M.A. Febbraio

Keyword(s):

High Intensity ◽

High Intensity Exercise ◽

Whole Body ◽

Physiological Strain ◽

And Performance

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Influence of endurance training on muscle [PCr] kinetics during high-intensity exercise

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00056.2007 ◽

2007 ◽

Vol 293 (1) ◽

pp. R392-R401 ◽

Cited By ~ 31

Author(s):

Andrew M. Jones ◽

Daryl P. Wilkerson ◽

Nicolas J. Berger ◽

Jonathan Fulford

Keyword(s):

Endurance Training ◽

High Intensity ◽

Slow Component ◽

Knee Extension ◽

High Intensity Exercise ◽

Whole Body ◽

Time To Exhaustion ◽

Exercise Tests ◽

Before And After ◽

Knee Extension Exercise

We hypothesized that a period of endurance training would result in a speeding of muscle phosphocreatine concentration ([PCr]) kinetics over the fundamental phase of the response and a reduction in the amplitude of the [PCr] slow component during high-intensity exercise. Six male subjects (age 26 ± 5 yr) completed 5 wk of single-legged knee-extension exercise training with the alternate leg serving as a control. Before and after the intervention period, the subjects completed incremental and high-intensity step exercise tests of 6-min duration with both legs separately inside the bore of a whole-body magnetic resonance spectrometer. The time-to-exhaustion during incremental exercise was not changed in the control leg [preintervention group (PRE): 19.4 ± 2.3 min vs. postintervention group (POST): 19.4 ± 1.9 min] but was significantly increased in the trained leg (PRE: 19.6 ± 1.6 min vs. POST: 22.0 ± 2.2 min; P < 0.05). During step exercise, there were no significant changes in the control leg, but end-exercise pH and [PCr] were higher after vs. before training. The time constant for the [PCr] kinetics over the fundamental exponential region of the response was not significantly altered in either the control leg (PRE: 40 ± 13 s vs. POST: 43 ± 10 s) or the trained leg (PRE: 38 ± 8 s vs. POST: 40 ± 12 s). However, the amplitude of the [PCr] slow component was significantly reduced in the trained leg (PRE: 15 ± 7 vs. POST: 7 ± 7% change in [PCr]; P < 0.05) with there being no change in the control leg (PRE: 13 ± 8 vs. POST: 12 ± 10% change in [PCr]). The attenuation of the [PCr] slow component might be mechanistically linked with enhanced exercise tolerance following endurance training.

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Scientific Opinion on the substantiation of health claims related to beta alanine and increase in physical performance during short term high intensity exercise (ID 436, 1453, 1454, 1459), increase in time to exhaustion (ID 437, 438, 439, 683, 1452, 1455,

EFSA Journal ◽

10.2903/j.efsa.2010.1729 ◽

2010 ◽

Vol 8 (10) ◽

pp. 1729

Author(s):

Keyword(s):

Physical Performance ◽

High Intensity ◽

High Intensity Exercise ◽

Health Claims ◽

Time To Exhaustion ◽

Short Term ◽

Beta Alanine ◽

Scientific Opinion

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Failure of Glycine-Arginine-α-Ketoisocaproic Acid to Improve High-Intensity Exercise Performance in Trained Cyclists

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.21.1.33 ◽

2011 ◽

Vol 21 (1) ◽

pp. 33-39 ◽

Cited By ~ 5

Author(s):

Lukas Beis ◽

Yaser Mohammad ◽

Chris Easton ◽

Yannis P. Pitsiladis

Keyword(s):

Exercise Performance ◽

High Intensity ◽

Perceived Exertion ◽

Cycle Ergometer ◽

High Intensity Exercise ◽

Ratings Of Perceived Exertion ◽

Mean Power ◽

Double Blind ◽

Oral Supplementation ◽

Experimental Trials

Oral supplementation with glycine-arginine-α-ketoisocaproic acid (GAKIC) has previously been shown to improve exhaustive high-intensity exercise performance. There are no controlled studies involving GAKIC supplementation in well-trained subjects. The aim of the current study was to examine the effects of GAKIC supplementation on fatigue during high-intensity, repeated cycle sprints in trained cyclists. After at least 2 familiarization trials, 10 well-trained male cyclists completed 2 supramaximal sprint tests each involving 10 sprints of 10 s separated by 50-s rest intervals on an electrically braked cycle ergometer. Subjects ingested 11.2 g of GAKIC or placebo (Pl) during a period of 45 min before the 2 experimental trials, administered in a randomized and double-blind fashion. Peak power declined from the 1st sprint (M ± SD; Pl 1,332 ± 307 W, GAKIC 1,367 ± 342 W) to the 10th sprint (Pl 1,091 ± 229 W, GAKIC 1,061 ± 272 W) and did not differ between conditions (p = .88). Mean power declined from the 1st sprint (Pl 892 ± 151 W, GAKIC 892 ± 153 W) to the 10th sprint (Pl 766 ± 120 W, GAKIC 752 ± 138 W) and did not differ between conditions (p = .96). The fatigue index remained at ~38% throughout the series of sprints and did not differ between conditions (p = .99). Heart rate and ratings of perceived exertion increased from the 1st sprint to the 10th sprint and did not differ between conditions (p = .11 and p = .83, respectively). In contrast to previous studies in untrained individuals, these results suggest that GAKIC has no ergogenic effect on repeated bouts of high-intensity exercise in trained individuals.

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Water Intake Accelerates Parasympathetic Reactivation After High-Intensity Exercise

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2013-0122 ◽

2014 ◽

Vol 24 (5) ◽

pp. 489-496 ◽

Cited By ~ 5

Author(s):

Tiago Peçanha ◽

Marcelle Paula-Ribeiro ◽

Edson Campana-Rezende ◽

Rhenan Bartels ◽

João Carlos Bouzas Marins ◽

...

Keyword(s):

Heart Rate ◽

Water Intake ◽

High Intensity ◽

Cycle Ergometer ◽

High Intensity Exercise ◽

Exercise Session ◽

Exponential Fitting ◽

Maximal Heart Rate ◽

Parasympathetic Reactivation ◽

Cardiovascular Benefit

It has been shown that water intake (WI) improves postexercise parasympathetic recovery after moderateintensity exercise session. However, the potential cardiovascular benefit promoted by WI has not been investigated after high-intensity exercise.Purpose:To assess the effects of WI on post high-intensity parasympathetic recovery.Methods:Twelve recreationally active young men participated in the study (22 ± 1.4 years, 24.1 ± 1.6 kg.m−2). The experimental protocol consisted of two visits to the laboratory. Each visit consisted in the completion of a 30-min high-intensity [~80% of maximal heart rate (HR)] cycle ergometer aerobic session performing randomly the WI or control (CON, no water consumption) intervention at the end of the exercise. HR and RR intervals (RRi) were continuously recorded by a heart rate monitor before, during and after the exercise. Differences in HR recovery [e.g., absolute heart rate decrement after 1 min of recovery (HRR60s) and time-constant of the first order exponential fitting curve of the HRR (HRRτ)] and in postexercise vagalrelated heart rate variability (HRV) indexes (rMSSD30s, rMSSD, pNN50, SD1 and HF) were calculated and compared for WI and CON.Results:A similar HR recovery and an increased postexercise HRV [SD1 = 9.4 ± 5.9 vs. 6.0 ± 3.9 millisecond, HF(ln) = 3.6 ± 1.4 vs. 2.4 ± 1.3 millisecond2, for WI and CON, respectively; p < .05] was observed in WI compared with CON.Conclusion:The results suggest that WI accelerates the postexercise parasympathetic reactivation after high-intensity exercise. Such outcome reveals an important cardioprotective effect of WI.

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