The Influence of Exercise on Tissue Beta-alanine Uptake and Carnosine Synthesis Rates

B-alanine supplementation is highly efficient in increasing intramuscular carnosine content, leading to improved physical performance, especially in high-intensity exercises (HIIE). It seems that exercise per se can modulate carnosine content; however, it remains uncertain whether physical training or training status can influence B-alanine supplementation responses. Thus, this work aims to assess whether HIIE can increase B-alanine uptake by peripheral tissues and, more specifically, skeletal muscle and increase intramuscular carnosine synthesis. The volunteers will be evaluated in two conditions: intake of B-alanine + exercise (B-EX) and B-alanine intake only (B-Ala). This process will be divided into two blocks of six days (Thursday to Thursday - without the weekend) with a 4-6 weeks washout. In the B-EX block, a 20-minute HIIE session will be held. In the B-Ala block, the same procedures will be adopted for the B-EX block, with the replacement of the HIIE for 20 minutes of rest sitting on the cycle ergometer. We will evaluate the determination of muscle B-alanine, plasma, and urine, the gene expression of carnosine-related enzymes and transporters, the enzymes Carnosine Synthase 1 (CARNS1), carnosine dipeptidase 2 (CN2), taurine transporter (TauT), PAT1, and phosphorylated Na + / K + / ATPase. The hypotheses are: 1) acute physical exercise increases the uptake of B-alanine by the skeletal muscle; 2) this effect is mediated by the increased activity of the Na + / K + / ATPase pump; 3) this effect, when repeated over five training sessions, results in observable increases in β-alanine → carnosine conversion in skeletal muscle.