This study investigates the effects of an acute dose of Rhodiola rosea on the endurance performance, the subjective perception of exertion (RPE), mood and cognitive functions. In a randomized, double-blind, crossover study with 18 healthy participants, subjects received either 3 mg/kg (body weight) of Rhodiola rosea or a placebo one hour before a 6-mile time trial on a cycle ergometer.
The results show:
- Faster time trial times: Subjects completed the time trial 40 seconds faster after Rhodiola administration (p = 0.037).
- Reduced subjective exertion (RPE)Participants perceived the exertion as significantly lower (p = 0.04).
- Lower heart rate during the warm-up: -4 bpm (p = 0.001) compared to the placebo group.
- No significant effect on lactate levels, cortisol or cognitive performance.
Conclusion: An acute dose of Rhodiola rosea can reduce the subjective perception of exertion and improve endurance performance. However, long-term effects or benefits for elite athletes need to be further investigated.
Background:
Rhodiola rosea is traditionally used to improve physical and mental resilience. Animal studies show that it can have antioxidant, anti-inflammatory and performance-enhancing effects. While previous studies suggest a possible improvement in physical performance, the results in humans are inconsistent. Some studies show an increased time to exhaustion, while others find no significant effects. This study therefore investigates whether a single dose of Rhodiola rosea affects endurance performance, subjective perception of exertion, cognitive function and stress response.
Methodology:
- Design: Randomized, double-blind, placebo-controlled crossover study.
- Participants: 18 healthy, trained recreational athletes (average age 22 ± 3.3 years).
- Intervention:
- Rhodiola rosea3 mg/kg body weight, standardized to 3 % rosavin and 1 % salidroside.
- Placebomaltodextrin capsule.
- Both substances were taken one hour before the test.
- Implementation:
- 10-minute warm-up.
- 6-mile time trial on a bicycle ergometer with variable incline.
- Collection of heart rate, subjectiverating of perceived exertion (RPE), blood lactate and saliva samples (cortisol & alpha-amylase).
- Stroop color test & mood questionnaire before and after the test.
- Statistical analysis: comparisons between placebo and rhodiola group with t-tests and ANOVA
Results:
Better endurance performance after Rhodiola administration:
- The participants completed the time trial significantly faster (p = 0.037).
- On average 40 seconds shorter time compared to the placebo group.
Reduced subjective exposure (RPE):
- participants perceived the stress as significantly lower (p = 0.04).
- This effect was even more pronounced when the RPE was considered relative to the work performed (watts)(p = 0.007).
Heart rate reduction during the warm-up:
- On average 4 beats per minute lower (p = 0.001).
- No significant change in heart rate during the time trial.
No significant effects on cortisol, alpha-amylase or lactate:
- The lactate values after the exercise test were identical in both groups.
- No significant difference in the stress response (cortisol & alpha-amylase).
No effect on cognitive performance (Stroop test) or mood:
No improvement in cognitive reaction time or mood after Rhodiola administration
Discussion:
The results suggest that Rhodiola rosea reduces the subjective perception of exertion and improves endurance performance, presumably through better mental resilience and central fatigue reduction.
Possible mechanisms:
- Reduction of sympathetic activation: lower heart rate during the warm-up.
- Influencing monoamine neurotransmitters (e.g. dopamine & serotonin), which could reduce the perception of exertion.
- Potential opioidergic effects: Previous studies show that Rhodiola may increase endogenous opioids, which could increase pain and exercise tolerance.
Why are not all studies consistent?
- Acute vs. long-term supplementation: While acute intake of Rhodiola shows positive effects, it may lose its effect with long-term use.
Individual differences: Some people may react more strongly to Rhodiola than others
Conclusion:
A single dose of Rhodiola rosea can reduce subjective stress and increase endurance performance. However, there are no evidence of a change in cognitive function or stress markers.
Practical application:
- Rhodiola could be of interest to recreational athletes and athletes who want to improve their endurance performance.
- Due to the lack of long-term effects , occasional use (e.g. before competitions) may be more appropriate than long-term use.
- The optimal dosage and long-term effects should be further investigated in future studies.