These studies may indicate further metabolism of adenosine before PX-478 becoming bioavailable and warrant further investigation. These effects of

ATP and adenosine could account, at least in part, for the improvements in low peak torque and torque fatigue we observed. The current study tested the hypothesis that oral ATP could improve performance during high intensity exercise. While we have shown this may be possible, the current study did not utilize methodologies to investigate the potential mechanism for the effects we observed. Further studies should incorporate measures of ATP and metabolites in blood components, should include measures of blood oxygenation and muscle blood flow, and also should investigate the extracellular role of ATP on the neuromuscular junction via Ca2+ mediated

effects [35] as indicators of the potential mechanism by which oral ATP affects the ability to perform strenuous exercise. Our study, like others in the literature, has limitations. The number of participants in the present study (n=16), while higher than that (n=9) previously studied by Jordan et al. [21], may not be sufficient to answer all the questions needed to validate the findings. Another limitation may relate to the timing of the last dose of oral ATP (or placebo) given. In our study the last dose was consumed 12 hours prior to testing. This contrasts with the study by Jordan et al. who studied participants after 14 days of supplementation and 3 hours cAMP post supplement dosing, and found ATP increased within group set 1 repetitions and total lifting volume [21]. Another potential GS-4997 datasheet limitation is that the study involved eumenorrheic females who were not differentiated based upon phase of the menstrual cycle. Other potential limitations include participants’ potential variation in physical

activity or diet before testing. However, participants did commit to maintaining their physical activity level for the duration of the study and to exercise restrictions for 3 days prior to testing which within a crossover design should have minimized the effect of activity on the results. Additionally, participants were required to repeat a similar dietary intake 24 h before each testing period and the testing was performed after an overnight fast which should have minimized any acute dietary effect on testing results. Conclusions In conclusion, the current study demonstrated that supplementation with 400 mg ATP/d for 15 days tended to reduce muscle fatigue while improving muscle low peak torque through Nocodazole supplier successive sets of exhaustive exercise. These effects may indicate an improvement in overall training stimulus which may have been brought about by more rapid repolarization and stronger action potentials later within sets, which should be investigated further. Electronic supplementary material Additional file 1: Table S1. Blood chemistry values before and after 15 days of supplementation with either a placebo or 400 mg ATP/d.