The Effects of an Acute Dose of Rhaponticum Carthamoides on Endurance Performance and Cognitive Function

Abstract

PURPOSE: The purpose of this study was to determine the effects of an acute dose of Rhaponticum carthamoides (RC) on endurance exercise performance, cognitive function and mood. METHODS: A total of 32 recreationally active college women (20.2±3.69 y, 60.1±8.0 kg; mean±SD) participated in this study. A week after a familiarization trial, subjects ingested either RC (10 mg/kg) or a carbohydrate placebo (PL) 1 hour prior to testing. Treatment order was assigned in a randomized, double blind manner. Exercise testing consisted of a standardized 10-min warm-up, followed by a 4-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 (RPE) using a BORG 10 pt scale. Saliva and blood samples were taken pre warm-up (A), 2-min post warm-up (B), and 2-min following completion of the time trial (C), and analyzed for cortisol and lactate concentration respectively. Subjects 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 7 days later to repeat the testing with the other condition. RESULTS: There were no significant differences between treatments for time to complete the time trial (RC=33.3±7.2 min, PL=33.2±7.6 min; mean±SD; p=0.98), or average RPE during the time trial (RC=5.0±1.2, PL=5.0±1.3; p=0.92). There were no significant differences between treatments in lactate at A (RC=1.38±0.9 mmol/l, PL=1.33±0.6 mmol/L; p=0.72), B (RC=2.74±0.9 mmol/l, PL=2.6±1.1 mmol/L; p=0.37), or C (RC=6.04±2.7 mmol/l, PL=6.05±2.0 mmol/L; p=0.99). There were no significant differences between treatments in cortisol at A (RC=0.29±0.1 μg/dL, PL=0.29±0.19 μg/dL; p=0.99), B (RC=0.24±0.08 μg/dL, PL=0.26±1.2 μg/dL; p=0.52), or C (RC=0.38±0.2 μg/dL, PL=0.35±0.14 μg/dL; p=0.7). There were no significant differences in the Stroop’s test between treatments pre (RC=60±21s, PL=60±22s; p=0.9) or post exercise (RC=57±21s, PL=56±21s; p=0.9). There were no significant differences between treatments at any time point for any of the mood states of the POMS. CONCLUSION: Acute Rhaponticum carthamoides ingestion does not improve endurance exercise performance, cognitive function, or mood.