The purpose of this study was to determine the effects of an acute oral dose of 3 mg/kg of Rhodiola rosea (R. rosea) on endurance exercise performance, mood, and cognitive function.
A total of 15 recreationally active college women (21.3 ± 0.09 y, 56.1 ± 6.3 kg; mean ± SD) participated in this study. 2–7 d after a familiarization trial subjects ingested in a double blind, random crossover manner, either R. rosea or a carbohydrate placebo 1 h prior to testing. Exercise testing consisted of a 10 minute warm-up, standardized to 80% of the average watts produced during the familiarization trial, followed by a 6 mile simulated indoor time trial on a Velotron electronic bicycle ergometer. Every 5 min during the time trial, subjects rated their level of perceived exertion using a BORG 10 pt scale. A blood sample was taken pre warm-up, 2 minutes post warm-up, and 2 minutes following completion of the time trial, and was analyzed for lactate concentration. Subjects also completed a Profile of Mood States (POMS) questionnaire and a Stroop's color test pre-warm up and following the completion of the time trial. Subjects returned to the lab 2–7 d later to repeat the testing with the other condition.
A 3 mg/kg acute does of R. rosea resulted in a shorter time to completion of the 6 mile time trial course (R. rosea 1544.7 ± 155.2 s, Placebo 1569.5 ± 179.4 s; mean ± SD; p = 0.06) as well as a lower average heart rate during the standardized warm up (R. rosea 138.6 ± 13.3 bpm, Placebo 143.7 ± 12.4 bpm; mean ± SD; p = 0.001). There were no significant differences between treatment conditions for rating of perceived exertion during the time trial. Both treatments resulted in a significant increase in the POMS fatigue score following exercise (p = 0.001), as well as a significant improvement following exercise for the Stroop's test of incongruent words (p = 0.001). No other significant differences between treatments were observed.
Acute Rhodiola rosea ingestion decreases the heart rate response to sub-maximal exercise, and appears to improve endurance exercise performance.