The Effects of an Acute Dose of Rhodiola Rosea on Endurance Exercise Performance
The purpose of this study was to determine the effects of an acute oral dose of 3mg/kg of Rhodiola Rosea (Rr) on endurance exercise performance, perceived exertion, mood, and cognitive function. Subjects (n=18) ingested either Rr or a carbohydrate placebo 1 h prior to testing in a double blind, random crossover manner. Exercise testing consisted of a standardized 10 min warm-up, followed by a 6-mile time trial (TT) on a bicycle ergometer. Perceived exertion (RPE) was measured every 5 min during the TT using a BORG 10 pt scale. Blood lactate concentration, salivary cortisol and salivary alpha amylase were measured pre warm-up, 2 min post warm-up, and 2 min post TT (n=15). A Profile of Mood States (POMS) questionnaire and a Stroop's Color Test were completed pre-warm up and post TT. Testing was repeated 2-7d later with the other condition. Rr ingestion significantly decreased heart rate during the standardized warm up (Rr=136+17bpm; Placebo=140+17bpm; mean+SD; p=0.001). Subjects completed the TT significantly faster following Rr ingestion (Rr=25.4+2.7 min; placebo=25.8+3.0 min; p=0.037). The mean RPE was lower in the Rr trial (Rr= 6.0+0.9; placebo= 6.6+1.0; p=0.04). This difference was even more pronounced when a ratio of the RPE relative to the workload was calculated (Rr= 0.048+0.01; placebo= 0.057+0.02; p=0.007). No other statistically significant differences were observed. Acute Rr ingestion decreases heart rate response to sub-maximal exercise, and appears to improve endurance exercise performance by decreasing the perception of effort.