Rhodiola Rosea is a medicinal plant that has been proven to improve work capacity, increase mental focus, support longer workouts, and reduce mental fatigue. Studies demonstrate that individuals who consume Rhodiola Rosea prior to exercise have higher levels of oxygen uptake and carbon dioxide output, and have a significantly greater time to exhaustion compared to individuals who consumed a placebo.

Effect
Magnitude of Effect
Level of Evidence
Consistency of Research
Conclusion
Studies
Fatigue
High ↓↓
10/10
Very High
The decrease in fatigue appears to be fairly strong and quite reliable when a low dose is given over a prolonged period of time or a high dose is given acutely.
Cognition
High ↑↑
8/10
Very High
Notably effective assuming fatigue is being reduced. There is insufficient evidence to evaluate rhodiola's effects on cognition without the fatigue reduction aspect
Rating of Perceived Exhaustion
Medium ↓
7/10
Medium
Evidence suggests a reduction in perceived exhaustion from aerobic exercise when taken acutely or chronically
Aerobic Exercise
Medium ↑
8/10
Very High
Evidence suggests a slight improvement in time to completion and time to exhaustion on cycle ergometer tests.