The Effect of Caffeine and Rhodiola Rosea, Alone or in Combination, on 5-km Running Performance in Men
Duncan Michael J Journal of Caffeine Research. February 2016, 6(1): 40-48.
Background: To examine the effect of acute Rhodiola Rosea (R.Rosea) ingestion, acute caffeine ingestion, or combined caffeine and R.Rosea on 5-km running time trial performance.
Methods: Twelve male recreational exercisers (mean age ± SD: 24.6 ± 6 years) undertook four trials each (placebo, caffeine [3 mg.kg−1], R.Rosea [3 mg.kg−1], and caffeine [3 mg.kg−1] and R.Rosea [3 mg.kg−1]) in a double-blind randomized order.
Results: There was a small but significant main effect of treatment for 5-km run time (p = 0.048) where performance was faster in the presence of caffeine compared with placebo, but not between any other combination of trials. Heart rate, blood lactate, and rating of perceived exertion increased with km run, irrespective of substance ingested (all p < 0.05). Scores for Felt Arousal increased preingestion to postingestion (p = 0.028) and were maintained to postexercise (p = 0.026), irrespective of the substance ingested. There was a small significant treatment × time interaction (p = 0.011, Pη2 = 0.255) for feeling scale (FS) scores, where postexercise FS scores were significantly lower after caffeine ingestion compared with the other substances ingested.
Conclusions: Acute caffeine ingestion (3 mg.kg−1) enhances 5-km time trial performance undertaken on a treadmill and results in more negative effect postexercise compared with ingestion of R.Rosea, combined R.Rosea and caffeine, and placebo. This study supports the efficacy of caffeine, but not R.Rosea, as an ergogenic aid for time running performance.
