Effect of oral creatine supplementation on power output and fatigue during bicycle ergometry

1995 ◽  
Vol 78 (2) ◽  
pp. 670-673 ◽  
Author(s):  
W. H. Cooke ◽  
P. W. Grandjean ◽  
W. S. Barnes
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Creatine Supplementation ◽  
Total Work ◽  
Fatigue Index ◽  
Bicycle Ergometry ◽  
Double Blind ◽  
Mean Values ◽  
Time To Peak

Our purpose was to determine the effect of oral creatine supplementation on exercise performance during high-intensity short-duration bicycle sprinting. Power output was recorded for 12 healthy untrained males (age 24.08 +/- 0.53 yr, weight 81.22 +/- 1.32 kg) before and after 5 days of creatine (n = 6) or placebo (n = 6) supplementation. A double-blind research design was employed. Subjects performed maximal sprints against a constant load (111.8 N) for 15 s. Each one-half pedal revolution was magnetically counted, and subsequent measurements of peak power, time to peak power, total work, and the fatigue index were digitized and stored on disk. Mean values for peak power, time to peak power, total work, and fatigue index were 958.01 +/- 40.66 W, 4.09 +/- 0.82 s, 11.28 +/- 0.46 kJ, and 32.1 +/- 1.58% decline from peak power, respectively. No significant differences were observed within or between groups before or after supplementation for any of the mechanical parameters measured (P > 0.05). These findings suggest that oral creatine supplementation does not positively affect power output or fatigue during continuous high-intensity bicycle exercise in untrained men.

The Effect of Continuous Low Dose Creatine Supplementation on Force, Power, and Total Work

2000 ◽  
Vol 10 (3) ◽  
pp. 235-244 ◽  
Author(s):  
Darren G. Burke ◽  
Shawn Silver ◽  
Laurence E. Holt ◽  
Truis Smith-Palmer ◽  
Christopher J. Culligan ◽  
...  
Keyword(s):  
Athletic Training ◽  
Short Duration ◽  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Low Dose ◽  
Creatine Supplementation ◽  
Peak Power Output ◽  
Total Work ◽  
Force Output

Dietary supplementation (SUP) has become a significant part of athletic training. Studies indicate that creatine (Cr) can enhance short-duration, high-intensity activities. This study examined the effect of 21 days of low dose Cr SUP (~7.7 g/day) and resistance training on force output, power output, duration of mean peak power output, and total work performed until fatigue. A double-blind protocol was used, where an individual, who was not part of any other aspect of the study, randomly assigned subjects to creatine and placebo groups. Forty-one male university athletes were randomly assigned to either Cr (n= 20) or placebo (n = 21) SUP. On the first and last day of the study, subjects were required to perform concentric bench press movements until exhaustion on an isokinetic dynamometer. The dynamometer was hard-wired to a personal computer, which provided force, velocity, and duration measures. Force and power output until fatigue, were used to determine total work, force-time, and power-time relationships. ANOVA results revealed that the Cr subjects performed more total work until fatigue, experienced significantly greater improvements in peak force and peak power, and maintained elevated mean peak power for a longer period of time. These results indicate that Cr SUP can significantly improve factors associated with short-duration, high-intensity activity.

CYP1A2 Genotype Polymorphism Influences the Effect of Caffeine on Anaerobic Performance in Trained Males

2021 ◽  
pp. 1-6
Author(s):  
Shahin Minaei ◽  
Morteza Jourkesh ◽  
Richard B. Kreider ◽  
Scott C. Forbes ◽  
Tacito P. Souza-Junior ◽  
...  
Keyword(s):  
Body Mass ◽  
Power Output ◽  
Peak Power ◽  
Anaerobic Power ◽  
Random Order ◽  
Peak Power Output ◽  
Fatigue Index ◽  
Double Blind ◽  
Minimum Power ◽  
Output Only

The purpose was to investigate the effects of CYP1A2 −163C > A polymorphism on the effects of acute caffeine (CAF) supplementation on anaerobic power in trained males. Sixteen trained males (age: 21.6 ± 7.1 years; height: 179.7 ± 5.6 cm; body mass: 72.15 ± 6.8 kg) participated in a randomized, double-blind, placebo (PLA) controlled crossover design. Participants supplemented with CAF (6 mg/kg of body mass) and an isovolumetric PLA (maltodextrin) in random order and separated by 7 days, before an all-out 30-s anaerobic cycling test to determine peak, average, and minimum power output, and fatigue index. Genomic deoxyribonucleic acid was extracted to identify each participants CYP1A2 genotype. Six participants expressed AA homozygote and 10 expressed C alleles. There was a treatment by genotype interaction for peak power output (p = .041, η2 = .265, observed power = 0.552) with only those expressing AA genotype showing improvement following CAF supplementation compared with PLA (CAF: 693 ± 108 watts vs. PLA: 655 ± 97 watts; p = .039), while no difference between treatments was noted in those expressing C alleles (CAF: 614 ± 92 watts vs. PLA: 659 ± 144 watts; p = .135). There were no other interaction or main effects for average or minimum power output, or fatigue index (p > .05). In conclusion, the ingestion of 6 mg/kg of CAF improved peak power output only in participants with the AA genotype compared with PLA; however, expression of the CYP1A2 did not influence average or minimum power output or fatigue index.

scholarly journals Effects of Creatine and Sodium Bicarbonate Coingestion on Multiple Indices of Mechanical Power Output During Repeated Wingate Tests in Trained Men

2015 ◽  
Vol 25 (3) ◽  
pp. 298-306 ◽  
Author(s):  
Corbin Griffen ◽  
David Rogerson ◽  
Mayur Ranchordas ◽  
Alan Ruddock
Keyword(s):  
Sodium Bicarbonate ◽  
Power Output ◽  
Mechanical Power ◽  
Total Work ◽  
Fatigue Index ◽  
Double Blind ◽  
Meaningful Improvement ◽  
Repeated Sprints ◽  
Double Blind Placebo ◽  
Mechanical Power Output

This study investigated the effects of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints. Nine well-trained men (age = 21.6 ± 0.9 yr, stature = 1.82 ± 0.05 m, body mass = 80.1 ± 12.8 kg) participated in a double-blind, placebo-controlled, counterbalanced, crossover study using six 10-s repeated Wingate tests. Participants ingested either a placebo (0.5 g·kg−1 of maltodextrin), 20 g·d−1 of creatine monohydrate + placebo, 0.3 g·kg−1 of sodium bicarbonate + placebo, or coingestion + placebo for 7 days, with a 7-day washout between conditions. Participants were randomized into two groups with a differential counterbalanced order. Creatine conditions were ordered first and last. Indices of mechanical power output (W), total work (J) and fatigue index (W·s−1) were measured during each test and analyzed using the magnitude of differences between groups in relation to the smallest worthwhile change in performance. Compared with placebo, both creatine (effect size (ES) = 0.37-0.83) and sodium bicarbonate (ES = 0.22-0.46) reported meaningful improvements on indices of mechanical power output. Coingestion provided small meaningful improvements on indices of mechanical power output (W) compared with sodium bicarbonate (ES = 0.28-0.41), but not when compared with creatine (ES = -0.21-0.14). Coingestion provided a small meaningful improvement in total work (J; ES = 0.24) compared with creatine. Fatigue index (W·s−1) was impaired in all conditions compared with placebo. In conclusion, there was no meaningful additive effect of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints.

The Influence of Recovery Duration on High-Intensity Exercise Performance After Oral Creatine Supplementation

1997 ◽  
Vol 22 (5) ◽  
pp. 454-467 ◽  
Author(s):  
William H. Cooke ◽  
William S. Barnes
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Creatine Supplementation ◽  
Cycle Ergometer ◽  
Peak Power Output ◽  
Significant Group ◽  
Before And After ◽  
Maximal Peak ◽  
Male Subjects

The purpose of this study was to determine the effects of creatine supplementation on the ability to reproduce and maintain a high percentage of peak power output during the second of two bouts of high-intensity cycle sprinting following four different recovery intervals. Eighty healthy, active male subjects were randomly assigned to one of two groups (creatine or placebo) and one of four recovery intervals (30, 60, 90, or 120 s). Two maximal cycle ergometer sprints, separated by the assigned recovery interval were performed before and after a 5-day supplementation protocol in which 20 g/day of creatine (plus 4 g/day glucose) or 24 g/day glucose placebo were ingested by subjects from creatine and placebo groups, respectively. Maximal peak power output (PP) and the absolute time to fatigue (TTF) were compared pre- versus postsupplementation. No significant group interactions were noted in this study. Specifically, creatine supplementation had no effect on subjects' ability to reproduce or maintain a high percentage of PP during the second bout of exercise. Key words: ergogenic aids, cycle ergometry, short-term fatigue

Reducing Anxiety and Anxiety Sensitivity With High-Intensity Interval Training in Adults With Asthma

2020 ◽  
Vol 17 (8) ◽  
pp. 835-839
Author(s):  
Carley O’Neill ◽  
Shilpa Dogra
Keyword(s):  
Anxiety Sensitivity ◽  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Interval Training ◽  
Peak Power Output ◽  
Sensitivity Index ◽  
High Intensity Interval Training ◽  
High Intensity Interval ◽  
The Impact

Background: Low- and moderate-intensity exercise training has been shown to be effective for reducing general anxiety and anxiety sensitivity among adults with asthma. Exercise frequency and intensity have been shown to play an integral role in reducing anxiety sensitivity; however, less is known about the impact of high-intensity interval training (HIIT) on anxiety in adults with asthma. Methods: A 6-week HIIT intervention was conducted with adults with asthma. Participants completed HIIT (10% peak power output for 1 min, 90% peak power output for 1 min, repeated 10 times) 3 times per week on a cycle ergometer. Preintervention and postintervention assessments included the Anxiety Sensitivity Index-3 and the Body Sensations Questionnaire. Results: Total Anxiety Sensitivity Index-3 (PRE: 17.9 [11.8]; POST 12.4 [13], P = .002, Cohen d = 0.4, n = 20) and Body Sensations Questionnaire (PRE: 2.4 [1.0]; POST: 2.0 [0.8], P = .007, Cohen d = 0.3) improved from preintervention to postintervention. Conclusion: A 6-week HIIT intervention leads to improved anxiety among adults with asthma. Future research should determine the impact of HIIT among adults with asthma with clinical anxiety.

Effects of Carbohydrate Ingestion and Carbohydrate Mouth Rinse on Repeat Sprint Performance

2017 ◽  
Vol 27 (3) ◽  
pp. 204-212 ◽  
Author(s):  
Ben M. Krings ◽  
Timothy J. Peterson ◽  
Brandon D. Shepherd ◽  
Matthew J. McAllister ◽  
JohnEric W. Smith
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Sprint Performance ◽  
Rating Of Perceived Exertion ◽  
Mouth Rinse ◽  
Total Work ◽  
Fatigue Index ◽  
Mean Power ◽  
Carbohydrate Ingestion ◽  
Mean Power Output

The purpose of this investigation was to examine to the influence of carbohydrate ingestion (CHOI) and carbohydrate mouth rinse (CHOR) on acute repeat maximal sprint performance. Fourteen healthy males (age: 21.7 ± 1.8 years, mass: 82.3 ± 12.3 kg) completed a total of five 15-s maximal repeat sprints on a cycle ergometer against 0.075 kg ・ kg-1 body mass each separated by 4 min of active recovery. Subjects completed four experimental trials and were randomly assigned one of four treatments: (1) CHOI, (2) CHOR, (3) placebo mouth rinse (PLAR), (4) placebo ingestion (PLAI). Subjects rinsed or ingested six 50 mL 10% CHO solutions throughout each trial. Performance variables measured included rating of perceived exertion, peak heart rate, peak and mean power output, fatigue index, and total work. Significant treatment main effects were observed for mean power output (p = 0.026), total work (p = 0.020), fatigue index (p = 0.004), and heart rate (p = 0.013). Overall mean power output and total work were significantly greater with CHOI (659.3 ± 103.0 watts, 9849.8 ± 1598.8 joules) compared with CHOR (645.8 ± 99.7 watts, 9447.5 ± 1684.9 joules, p < .05). CHOI (15.3 ± 8.6 watts/s) significantly attenuated fatigue index compared with CHOR (17.7 ± 10.4 watts/s, p < .05). Based on our findings, CHOI was more likely to provide a beneficial performance effect compared with CHOR, PLAI, and PLAR. Athletes required to complete repeat bouts of high intensity exercise may benefit from CHOI.

N-acetylcysteine alters substrate metabolism during high-intensity cycle exercise in well-trained humans

2013 ◽  
Vol 38 (12) ◽  
pp. 1217-1227 ◽  
Author(s):  
Adam J. Trewin ◽  
Aaron C. Petersen ◽  
Francois Billaut ◽  
Leon R. McQuade ◽  
Bernie V. McInerney ◽  
...  
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Repeated Measures ◽  
Vastus Lateralis ◽  
Venous Blood ◽  
Time Trial ◽  
Peak Power Output ◽  
Mean Power ◽  
Double Blind ◽  
Substrate Metabolism

We investigated the effects of N-acetylcysteine (NAC) on metabolism during fixed work rate high-intensity interval exercise (HIIE) and self-paced 10-min time-trial (TT10) performance. Nine well-trained male cyclists (V̇O2peak, 69.4 ± 5.8 mL·kg−1·min−1; peak power output (PPO), 385 ± 43 W; mean ± SD) participated in a double-blind, repeated-measures, randomised crossover trial. Two trials (NAC supplementation and placebo) were performed 7 days apart consisting of 6 × 5 min HIIE bouts at 82% PPO (316 ± 40 W) separated by 1 min at 100 W, and then after 2 min of recovery at 100 W, TT10 was performed. Expired gases, venous blood, and electromyographic (EMG) data were collected. NAC did not influence blood glutathione but decreased lipid peroxidation compared with the placebo (P < 0.05). Fat oxidation was elevated with NAC compared with the placebo during HIIE bouts 5 and 6 (9.9 ± 8.9 vs. 3.9 ± 4.8 μmol·kg−1·min−1; P < 0.05), as was blood glucose throughout HIIE (4.3 ± 0.6 vs. 3.8 ± 0.6 mmol·L−1; P < 0.05). Blood lactate was lower with NAC after TT10 (3.3 ± 1.3 vs. 4.2 ± 1.3 mmol·L−1; P < 0.05). Median EMG frequency of the vastus lateralis was lower with NAC during HIIE (79 ± 10 vs. 85 ± 10 Hz; P < 0.05), but not TT10 (82 ± 11 Hz). Finally, NAC decreased mean power output 4.9% ± 6.6% (effect size = –0.3 ± 0.4, mean ± 90% CI) during TT10 (305 ± 57 W vs. 319 ± 45 W). These data suggest that NAC alters substrate metabolism and muscle fibre type recruitment during HIIE, which is detrimental to time-trial performance.

scholarly journals Caffeine Increases Muscle Performance During a Bench Press Training Session

2020 ◽  
Vol 74 (1) ◽  
pp. 185-193
Author(s):  
Verónica Giráldez-Costas ◽  
Jaime González-García ◽  
Beatriz Lara ◽  
Juan Del Coso ◽  
Michal Wilk ◽  
...  
Keyword(s):  
Power Output ◽  
Bench Press ◽  
Training Session ◽  
Muscle Performance ◽  
Peak Power Output ◽  
Maximal Velocity ◽  
Total Work ◽  
Mean Power ◽  
Double Blind ◽  
Bar Velocity

Abstract Previous investigations have established the ergogenic effect of caffeine on maximal muscle strength, power output and strength-endurance. However, these investigations used testing protocols that do not replicate the structure of a regular strength training session. Thus, the aim of this study was to investigate the effect of acute caffeine ingestion on muscle performance during a simulated velocity-based training workout. In a double-blind, randomized and counterbalanced experiment, 12 participants performed two experimental trials after ingesting 3 mg/kg/b.m. of caffeine or a placebo. The trials consisted of 4 sets of 8 repetitions of the bench press exercise at 70% of their one-repetition maximum performed at maximal velocity. Bar velocity was recorded with a rotatory encoder and force, power output and work were calculated. Regarding the whole workout, caffeine increased mean bar velocity (+7.8%; p=0.002), peak bar velocity (+8.7%; p=0.006), mean force (+1.5%; p=0.002), mean power output (+10.1%; p=0.003) and peak power output (+8.2%; p=0.004) when compared to the placebo. The total work performed in the caffeine trial was superior to the placebo trial (7.01±2.36 vs 6.55±2.20 kJ, p=0.001). These results suggest that the acute intake of 3 mg/kg/b.m. of caffeine before a velocity-based strength workout increased muscle performance and the total work performed across the whole training session. Thus, caffeine can be considered as an effective strategy to enhance muscle performance during the bench press training sessions.

scholarly journals MODERATE INTENSITY IS A BETTER STIMULUS TO INDUCE QUADRIPECS FEMORIS POWER IN ELDERLY ADULTS

2018 ◽  
Vol 24 (3) ◽  
pp. 230-233
Author(s):  
João Pedro Pinho ◽  
Bruno Mezêncio ◽  
Arnaldo José Hernandez ◽  
Jéssica Bonato ◽  
Wellington Masuko ◽  
...  
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Peak Power ◽  
Elderly Women ◽  
Load Condition ◽  
Knee Extensor ◽  
Moderate Intensity ◽  
Moderate Load ◽  
Intensity Condition ◽  
Load Conditions

ABSTRACT Introduction: The best strategy for improving knee extensor power, a major functional capacity indicator in older adults, is power training. Nonetheless, the training intensity required to induce optimal gains is yet to be found. Objective: Our purpose was to compare knee extensor peak power responses between low, moderate, and high intensity load conditions (30%, 50% and 70% of 1RM). Methods: Thirteen sedentary elderly women performed six knee extensions in each load condition, calculating knee extensor mechanical work/power output and knee extension peak angular velocity. Results: No difference in peak power was found between the high (207.0 ± 68.1 W) and moderate (206.1 ± 71.6 W) load conditions (p = 0.994), and both had higher values (p ≤0.004) than the low intensity condition (135.6 ± 56.3 W). Conclusion: Moderate load at 50% of 1RM appears to be the preferred strategy for inducing knee extensor power output because in contrast with the high intensity condition, the moderate load yielded higher angular peak velocity, which is also a functional indicator. Level of Evidence ll; Therapeutic studies - Investigating treatment results.

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