Failure of Rhodiola rosea to alter skeletal muscle phosphate kinetics in trained men

Rhodiola rosea is an herbal supplement purported to improve resistance to stressors and to enhance physical performance, potentially by improving adenosine triphosphate (ATP) turnover. Phosphocreatine (PCr) kinetics serves as a reflection of ATP turnover. The purpose of this investigation was to examine the effect of R rosea ingestion on human skeletal muscle PCr recovery after exhaustive exercise. Twelve resistance-trained men, aged 19 to 39 years, completed incremental forearm wrist flexion exercise to volitional fatigue, once after ingesting 1500 mg R rosea per day for 4 days, and once after ingesting an equivalent placebo dose. During exercise and recovery from exercise, muscle phosphates were examined using phosphorus 31 nuclear magnetic resonance spectroscopy. [PCr] during recovery was fit with a monoexponential function, and the resulting rate constants (k) were compared between groups. Rating of perceived exertion per stage and time to exhaustion were also compared between groups. For R rosea, k = 0.3744 ± 0.1532, whereas for placebo, k = 0.3956 ± 0.2238. Although rating of perceived exertion significantly increased within groups as workload increased, it did not differ between conditions, nor did time to exhaustion (R rosea, 10.71 ± 0.54 minutes; placebo, 10.48 ± 0.68 minutes). Estimates of [PCr] at time 0, 5, 10, 15, and 20 minutes of recovery were nearly identical between groups. In summary, there were no significant differences between groups for any of theparameters measured. Based on these results, we conclude that R rosea ingestion does not improve ATP turnover during or immediately after exercise.