Effect Of Resistance Training On Carnosine Concentration In Human Skeletal Muscle

Abstract

Carnosine (β-alanyl-L-histidine) is a dipeptide containing histidine and is present in vertebrate skeletal muscles. It has been reported that carnosine contributes to physico-chemical buffering to maintain acid-base balance during high-intensity exercise. Moreover, it has been shown that the repeated accumulation of hydrogen ion with high-intensity exercise training is necessary to increase in carnosine concentration. However, the effects of most type of the training on skeletal muscle carnosine concentration are unclear. PURPOSE: The purpose of the present study was to determine the effects of resistance training on skeletal muscle carnosine concentration. METHODS: Fifteen active but not well-trained healthy males were assigned to either a "Strength-type“ (S-type: n = 7) or a "Hypertrophy type“ (H-type: n = 8) group and performed leg press exercise twice a week for 8 weeks. The S-type regimen consisted of 5 sets at 90% of 1 repetition maximum (RM) with 3-min rest periods between sets, whereas the H-type regimen consisted of 5 sets at 70% of 1RM with 1-min rest periods between sets. Muscle volume was measured using a magnetic resonance imaging (MRI). Muscle biopsy samples were taken from the vastus lateralis at rest before and after training. The carnosine concentration was determined using an amino acid autoanalyzer. RESULTS: After the 8 weeks of resistance training, muscle volume of thigh and 1RM of leg press were significantly (p < 0.05) increased in both groups. In addition, percentage change in muscle volume was larger in the H-type group than that in the S-type group. However, carnosine concentration was not significantly increased in either group. CONCLUSIONS: These results suggest that resistance training does not improve skeletal muscle carnosine concentration regardless of the type of regimen.