Evidences suggest that intramuscular acidosis is one of the major causes of fatigue during high-intensity exercise. Carnosine is a dipeptide found in skeletal muscle and its most reported role is of pH buffering. The effect of beta-alanine supplementation in increasing muscular carnosine content is well established. However, it has been suggested that high-intensity intermittent training could also increase carnosine concentration; however, data of longitudinal studies are limited. Besides, whether the combination of beta-alanine supplementation and intermittent training is more effective in increasing muscle carnosine than each treatment alone, as well as if this increasing would reflect in improvements in performance remain unknown. Therefore, this study aims to investigate the effects of 12 weeks of high-intensity intermittent training associated or not to 12 weeks of beta-alanine supplementation on muscle carnosine concentration and exercise performance. A total of 30 volunteers will be randomly assigned to beta-alanine (BA, n = 15) or placebo (PLA, n = 15) groups, followed by another randomization of one of the volunteer's legs to "Trained" (n = 15) or "Untrained" (n = 15) groups. In addition, 15 individuals will be recruited for a control group without training or supplementation interventions. Training will be performed only on the ipsilateral leg and the contralateral leg will be set as control. Both training and supplementation will last for 12 weeks. Muscle biopsies of participant's vastus lateralis muscle to determine intramuscular content of carnosine will be performed, as well as maximum voluntary isometric contraction of lower limbs, and also exercise capacity and VO2max before, during and after 12 weeks. Descriptive data analyses will be performed along mixed-models for repeated measurements. The level of significance will be of 5%.
News published in Agência FAPESP Newsletter about the scholarship: