Anaerobic Power Responses to Amino Acid Nutritional Supplementation

1991 ◽  
Vol 1 (4) ◽  
pp. 366-377 ◽  
Author(s):  
Carl M. Maresh ◽  
Catherine L. Gabaree ◽  
Jay R. Hoffman ◽  
Daniel R. Hannon ◽  
Michael R. Deschenes ◽  
...  
Keyword(s):  
Exercise Performance ◽  
High Intensity ◽  
Peak Plasma ◽  
Anaerobic Power ◽  
High Intensity Exercise ◽  
Control Measures ◽  
Plasma Lactate ◽  
Mean Power ◽  
Exercise Tests ◽  
Double Blind

To examine the effect of a nutritional supplement (ATP-E™) on high intensity exercise performance, 23 physically active males volunteered to perform six Wingate Anaerobic Power tests. Tests were performed prior to and at 14 and 21 days during ATP-E~o~r placebo ingestion. f i e experiment followed a double-blind and random-order design. Twelve subjects (responders, R) showed an increase in preexercise blood ATP on Day 14 of ATP-E™ ingestion compared to control measures. The remaining 11 subjects (nonresponders, NR) had no change in pree~e~cibselo od ATP. Peak power and mean power were unchanged for both R and NR subjects across the exercise tests, but R experienced a decrease (p< 0.05) in immediate postexercise plasma lactate on Day 14 of ATP-E™ testing compared to their control measures. NR had no change in peak plasma lactate at any time during the study. The results suggest that short-term high intensity exercise performance was maintained in R with less reliance on anaerobic metabolism, and that response was evident following 14 days of ATP-E™ ingestion.

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

2011 ◽  
Vol 21 (1) ◽  
pp. 33-39 ◽  
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.

Pseudoephedrine is without ergogenic effects during prolonged exercise

1996 ◽  
Vol 81 (6) ◽  
pp. 2611-2617 ◽  
Author(s):  
Hunter Gillies ◽  
Wayne E. Derman ◽  
Timothy D. Noakes ◽  
Peter Smith ◽  
Alicia Evans ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
High Intensity ◽  
Muscle Function ◽  
Prolonged Exercise ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
High Intensity Exercise ◽  
Double Blind ◽  
Drug Concentrations ◽  
Ergogenic Effects

Gillies, Hunter, Wayne E. Derman, Timothy D. Noakes, Peter Smith, Alicia Evans, and Gary Gabriels.Pseudoephedrine is without ergogenic effects during prolonged exercise. J. Appl. Physiol. 81(6): 2611–2617, 1996.—This study was designed to measure whether a single dose of 120 mg pseudoephedrine ingested 120 min before exercise influences performance during 1 h of high-intensity exercise. The effects of exercise on urinary excretion of the drug were also studied. Ten healthy male cyclists were tested on two occasions, separated by at least 7 days, by using a randomly assigned, double-blind, placebo-controlled, crossover design. Exercise performance was tested during a 40-km trial on a laboratory cycle ergometer, and skeletal muscle function was measured during isometric contractions. On a third occasion, subjects ingested 120 mg pseudoephedrine but did not exercise [control (C)]. Pseudoephedrine did not influence either time trial performance [drug (D) vs. placebo: 58.1 ± 1.4 (SE) vs. 58.7 ± 1.5 min] or isometric muscle function. Urinary pseudoephedrine concentrations were significantly increased 1 h after exercise (D vs. C: 114.3 ± 27.2 vs. 35.4 ± 13.1 μg/ml; P < 0.05). Peak plasma pseudoephedrine concentrations ( P < 0.05) but not time taken to reach peak plasma concentrations or the area under the plasma pseudoephedrine concentration vs. time curve was significantly increased in the total group with exercise (D vs. C). In three subjects, plasma pseudoephedrine concentrations were not influenced by exercise. Only these subjects showed increased urinary pseudoephedrine excretion during exercise. We conclude that a single therapeutic dose of pseudoephedrine did not have a measurable ergogenic effect during high-intensity exercise of 1-h duration, but plasma drug concentrations and urinary excretion were altered by exercise. These findings have practical relevance to doping control regulations in international sporting competitions.

Practical application of fundamental concepts in exercise physiology

2007 ◽  
Vol 31 (4) ◽  
pp. 347-351 ◽  
Author(s):  
R. Ramsbottom ◽  
R. F. T. Kinch ◽  
M. G. Morris ◽  
A. M. Dennis
Keyword(s):  
Critical Thinking ◽  
High Intensity ◽  
Ventilatory Threshold ◽  
Exercise Physiology ◽  
Anaerobic Power ◽  
Thinking Skills ◽  
High Intensity Exercise ◽  
Aerobic Performance ◽  
Primary Data ◽  
Mean Power

The collection of primary data in laboratory classes enhances undergraduate practical and critical thinking skills. The present article describes the use of a lecture program, running in parallel with a series of linked practical classes, that emphasizes classical or standard concepts in exercise physiology. The academic and practical program ran under the title of a particular year II module named Sports Performance: Physiology and Assessment, and results are presented over a 3-yr period (2004–2006), based on an undergraduate population of 31 men and 34 women. The module compared laboratory-based indexes of endurance (e.g., ventilatory threshold and exercise economy) and high-intensity exercise (e.g., anaerobic power), respectively, with measures of human performance (based on 20-m shuttle run tests). The specific experimental protocols reinforced the lecture content to improve student understanding of the physiological and metabolic responses (and later adaptations) to exercise. In the present study, the strongest relationship with endurance performance was the treadmill velocity at maximal aerobic power ( r = +0.88, P < 0.01, n = 51); in contrast, the strongest relationship with high-intensity exercise performance was the mean power output (in W/kg) measured during a 30-s all-out cycle ergometer sprint ( r = +0.80, P < 0.01, n = 48). In class student data analysis improved undergraduate indepth or critical thinking during seminars and enhanced computer and data presentation skills. The endurance-based laboratories are particularly useful for examining the underlying scientific principles that determine aerobic performance but could equally well be adapted to investigate other topics, e.g., differences in the exercise response between men and women.

Dietary Supplementation and Improved Anaerobic Performance

1994 ◽  
Vol 4 (4) ◽  
pp. 387-397 ◽  
Author(s):  
Carl M. Maresh ◽  
Lawrence E. Armstrong ◽  
Jay R. Hoffman ◽  
Daniel R. Hannon ◽  
Catherine L. V. Gabaree ◽  
...  
Keyword(s):  
Test Performance ◽  
Peak Plasma ◽  
Dietary Supplementation ◽  
Wingate Test ◽  
Entire Group ◽  
Anaerobic Performance ◽  
Plasma Lactate ◽  
Mean Power ◽  
Double Blind ◽  
Daily Dose

In the present study, the effects of an increased daily dose of a dietary supplement (ATP-E, 0.2 g ··) on Wingate test performance were examined in 12 men (21 ± 1.6 years) prior to and following 14 days of supplement and placebo ingestion. A double-blind and counterbalanced design was used. Results revealed higher (p< .007) preexercise blood ATP (95.4 ± 10.5 μmol ·) for the entire group following 14 days of ATP-E ingestion compared to placebo measures (87.6 ± 10.9 μmol ·). Mean power (667 ± 73 W) was higher (p< .008) after 14 days of ATP-E ingestion versus placebo (619 ± 67 W). Peak plasma lactate was lower (p< .07) after 14 days of ATP-E ingestion (14.9 ± 2.8 mmol ·) compared to placebo (16.3 ± 1.6 mmol ·). These data suggested that the improvement in 30-s Wingate test performance in this group may be related to the increased dose of ATP-E.

Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans

2010 ◽  
Vol 109 (1) ◽  
pp. 135-148 ◽  
Author(s):  
Stephen J. Bailey ◽  
Jonathan Fulford ◽  
Anni Vanhatalo ◽  
Paul G. Winyard ◽  
Jamie R. Blackwell ◽  
...  
Keyword(s):  
High Intensity ◽  
Force Production ◽  
Knee Extensor ◽  
High Intensity Exercise ◽  
Nitrate Content ◽  
Time To Exhaustion ◽  
Exercise Tests ◽  
Double Blind ◽  
Dietary Nitrate ◽  
Low Intensity

The purpose of this study was to elucidate the mechanistic bases for the reported reduction in the O2cost of exercise following short-term dietary nitrate (NO3−) supplementation. In a randomized, double-blind, crossover study, seven men (aged 19–38 yr) consumed 500 ml/day of either nitrate-rich beetroot juice (BR, 5.1 mmol of NO3−/day) or placebo (PL, with negligible nitrate content) for 6 consecutive days, and completed a series of low-intensity and high-intensity “step” exercise tests on the last 3 days for the determination of the muscle metabolic (using31P-MRS) and pulmonary oxygen uptake (V̇o2) responses to exercise. On days 4–6, BR resulted in a significant increase in plasma [nitrite] (mean ± SE, PL 231 ± 76 vs. BR 547 ± 55 nM; P < 0.05). During low-intensity exercise, BR attenuated the reduction in muscle phosphocreatine concentration ([PCr]; PL 8.1 ± 1.2 vs. BR 5.2 ± 0.8 mM; P < 0.05) and the increase in V̇o2(PL 484 ± 41 vs. BR 362 ± 30 ml/min; P < 0.05). During high-intensity exercise, BR reduced the amplitudes of the [PCr] (PL 3.9 ± 1.1 vs. BR 1.6 ± 0.7 mM; P < 0.05) and V̇o2(PL 209 ± 30 vs. BR 100 ± 26 ml/min; P < 0.05) slow components and improved time to exhaustion (PL 586 ± 80 vs. BR 734 ± 109 s; P < 0.01). The total ATP turnover rate was estimated to be less for both low-intensity (PL 296 ± 58 vs. BR 192 ± 38 μM/s; P < 0.05) and high-intensity (PL 607 ± 65 vs. BR 436 ± 43 μM/s; P < 0.05) exercise. Thus the reduced O2cost of exercise following dietary NO3−supplementation appears to be due to a reduced ATP cost of muscle force production. The reduced muscle metabolic perturbation with NO3−supplementation allowed high-intensity exercise to be tolerated for a greater period of time.

Creatine Monohydrate Supplementation Enhances High-Intensity Exercise Performance in Males and Females.

2000 ◽  
Vol 10 (4) ◽  
pp. 452-463 ◽  
Author(s):  
Mark A. Tarnopolsky ◽  
Dan P. MacLennan
Keyword(s):  
Exercise Performance ◽  
High Intensity ◽  
Statistical Power ◽  
Handgrip Strength ◽  
Creatine Supplementation ◽  
Voluntary Contraction ◽  
Creatine Monohydrate ◽  
High Intensity Exercise ◽  
Double Blind ◽  
Males And Females

Creatine monohydrate supplementation has been shown to enhance high-intensity exercise performance in some but not all studies. Part of the controversy surrounding the ergogenic effect(s) of creatine monohydrate supplementation may relate to design issues that result in low statistical power. A further question that remains unresolved in the creatine literature is whether or not males and females respond in a similar manner to supplementation. We studied the effect of creatine supplementation upon high intensity exercise performance in 24 subjects (n = 12 males, n = 12 females). Creatine monohydrate (Cr; 5g, 4x/d × 4d) and placebo (PI; glucose polymer × 4d) were provided using a randomized. double-blind crossover design (7 week washout). Outcome measures included: 2 × 30-S anaerobic cycle lest, with plasma lactate pre- and post-test; dorsi-flexor: maximal voluntary contraction (MVC), 2-min fatigue test, and electrically stimulated peak and tetanic torque; isokinetic knee extension torque and I -min ischeniic handgrip strength. Significant main effects of Cr treatment included: increased peak and relative peak anaerobic cycling power (↑3.7%; p < .05), dorsi-flexion MVC torque (↑6.6% p < .05), and increased lactate (↑20.8%; p < .05) with no gender specific responses. We concluded that short-term Cr supplementation can increase indices of high-intensity exercise performance for both males and females.

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

2007 ◽  
Vol 293 (1) ◽  
pp. R392-R401 ◽  
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.

Effects of Antioxidant Supplementation on Exercise Performance in Acute Normobaric Hypoxia

2014 ◽  
Vol 24 (2) ◽  
pp. 227-235 ◽  
Author(s):  
Christian Mariacher ◽  
Hannes Gatterer ◽  
Joachim Greilberger ◽  
Radoslav Djukic ◽  
Michaela Greilberger ◽  
...  
Keyword(s):  
Aerobic Exercise ◽  
Exercise Performance ◽  
Beta Carotene ◽  
Cycling Performance ◽  
Normobaric Hypoxia ◽  
Alpha Tocopherol ◽  
Maximal Heart Rate ◽  
Exercise Tests ◽  
Double Blind ◽  
Concentrate Supplementation

Background/Objectives:To compare the effects of a 3-week supplementation between two different mixtures of antioxidants and placebo on aerobic exercise performance in acute normobaric hypoxia.Subjects/Methods:Seventeen subjects were randomly assigned in a double-blind fashion to receive a broad-based antioxidants supplement containing beta-carotene, ascorbic acid, d-alpha-tocopherol-succinate, N-acetylcysteine, riboflavin, zinc, and selenium (antioxidant capsule group [AO group]), or a combination of alpha-ketoglutaric acid (α-KG) and 5-hydroxymethylfurfural (5-HMF; CYL concentrate supplementation group [CS group]), or placebo (PL group). Before and after supplementation, subjects performed two incremental cycle-exercise tests until exhaustion. The first test was conducted under normoxic conditions (LA, FiO2 of 20.9%, ~547 m) and the second after the 3-week supplementation period under normobaric hypoxic conditions (AHA, FiO2 of 12.9%, ~4300m).Results:In CS peak cycling performance (peak power) declined from LA to AHA 7.3% (90% CI: 2.2–12.4) less compared with PL (p = .04) and 6.7% (90%CI: 3.2–10.2) less compared with AO (p = .03). Better maintenance of aerobic exercise capacity in CS was associated with an attenuated reduction in maximal heart rate in hypoxia.Conclusions:Aerobic exercise performance was less impaired in acute normobaric hypoxia after 3 weeks with supplementation of α-KG and 5-HMF compared with a broad-based antioxidants supplement or PL.

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