AVAILABILITY OF RIBOSE IS LIMITING FOR ATP RESYNTHESIS IN HUMAN SKELETAL MUSCLE AFTER HIGH-INTENSITY TRAINING

Abstract

The main aim of the project was to examine whether the availability of ribose was limiting for the resynthesis of skeletal muscle ATP after high-intensity training in humans. Six male subjects performed a double-blind cross-over design seperated by about 6 weeks. Each subject performed high-intensity intermittent training on a Wingate ergometer cycle twice a day for seven days followed by a ribose or placebo supplementation period of 72h. Training session consisted of fifteen 10s all-out sprints with 50s of rest between bouts. The supplementation consisted of either a placebo or ribose mixture (200 mg·kg BM−1 ribose) dissolved in 500 ml water. Muscle biopsies were taken at rest in m. vastus lateralis before the start of training and at 5h and 72h after the last training session. In the control trial the levels of ATP and total adenine nucleotides (TAN) were lower at 5h (21.7 ± 0.7 [± SEM] and 25.2 ± 0.8 mmol/kg dry wt) and 72h (21.1 ± 0.6 and 24.5 ± 0.7 mmol/kg dry wt) post-training than pre-training (25.9 ± 0.5 and 29.6 ± 0.7 mmol/kg dry wt) (P < 0.001). In the ribose trial the levels of ATP and TAN were lower at 5h post-training (21.4 ± 1.2 and 25.1 ± 1.3 mmol/kg dry wt) than pre-training (26.5 ± 0.9 and 30.3 ± 1.0 mmol/kg dry wt) (P < 0.01), whereas the levels at 72h post-training (24.2 ± 0.9 and 27.7 ± 0.5 mmol/kg dry wt) were not different from pre-training values (P > 0.05). The results from this study support previous observations that high-intensity training in humans can cause a decrease in resting levels of skeletal muscle adenine nucleotides, and demonstrates that availability of ribose is limiting for the resynthesis of ATP. Supported by Bioenergy Inc., MN, USA