Back to Search
Start Over
Doubling of muscle carnosine concentration does not improve laboratory 1-hr cycling time-trial performance.
- Source :
-
International journal of sport nutrition and exercise metabolism [Int J Sport Nutr Exerc Metab] 2014 Jun; Vol. 24 (3), pp. 315-24. Date of Electronic Publication: 2014 Jan 17. - Publication Year :
- 2014
-
Abstract
- Muscle carnosine loading through chronic oral beta-alanine supplementation has been shown to be effective for short-duration, high-intensity exercise. This randomized, placebo-controlled study explored whether the ergogenic effect of beta-alanine supplementation is also present for longer duration exercise. Subjects (27 well-trained cyclists/triathletes) were supplemented with either beta-alanine or placebo (6.4 g/day) for 6 weeks. Time to completion and physiological variables for a 1-hr cycling time-trial were compared between preand postsupplementation. Muscle carnosine concentration was also assessed via proton magnetic resonance spectroscopy before and after supplementation. Following beta-alanine supplementation, muscle carnosine concentration was increased by 143 ± 151% (mean ± SD; p < .001) in the gastrocnemius and 161 ± 56% (p < .001) in the soleus. Postsupplementation time trial performance was significantly slower in the placebo group (60.6 ± 4.4-63.0 ± 5.4 min; p < .01) and trended toward a slower performance following beta-alanine supplementation (59.8 ± 2.8-61.7 ± 3.0 min; p = .069). We found an increase in lactate/proton concentration ratio following beta-alanine supplementation during the time-trial (209.0 ± 44.0 (beta-alanine) vs. 161.9 ± 54.4 (placebo); p < .05), indicating that a similar lactate concentration was accompanied by a lower degree of systemic acidosis, even though this acidosis was quite moderate (pH ranging from 7.30 to 7.40). In conclusion, chronic beta-alanine supplementation in well-trained cyclists had a very pronounced effect on muscle carnosine concentration and a moderate attenuating effect on the acidosis associated with lactate accumulation, yet without affecting 1-h time-trial performance under laboratory conditions.
- Subjects :
- Acidosis prevention & control
Dietary Supplements
Humans
Hydrogen-Ion Concentration
Lactic Acid blood
Male
Physical Exertion drug effects
Athletic Performance physiology
Bicycling physiology
Carnosine metabolism
Exercise physiology
Muscle, Skeletal drug effects
Muscle, Skeletal metabolism
Physical Endurance drug effects
beta-Alanine pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 1543-2742
- Volume :
- 24
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- International journal of sport nutrition and exercise metabolism
- Publication Type :
- Academic Journal
- Accession number :
- 24457999
- Full Text :
- https://doi.org/10.1123/ijsnem.2013-0125