Rhodiola Rosea for Endurance Athletes: The Evidence

Rhodiola rosea has gone mainstream in endurance communities, largely on the strength of Andrew Huberman's repeated recommendations on his podcast. He describes taking 100 to 200mg before workouts to reduce the perceived difficulty of exercise. The r/HubermanLab community, which has over 150,000 members, has generated hundreds of threads on the topic since 2022.

That visibility is well-earned. Rhodiola's performance and recovery effects have real research behind them. But the way it is typically discussed online creates two problems: people expect it to work like caffeine (immediately and acutely), and they do not know what to do about cycling.

This article covers what rhodiola actually does, the evidence behind it, how to use it correctly, and why it is one of the two adaptogen components in Endurance360.

What Rhodiola Does

Rhodiola rosea is an adaptogen, which means its primary function is helping the body maintain homeostasis under stress. For endurance athletes, that stress is a high training load. Here is what the research shows:

Reduces rate of perceived exertion (RPE). A 2004 study published in the International Journal of Sport Nutrition and Exercise Metabolism found that rhodiola supplementation significantly reduced RPE during submaximal exercise. Athletes felt like they were working less hard at the same pace. This is the effect Huberman is referencing when he talks about workouts feeling easier.

Blunts cortisol response. Prolonged high-intensity training elevates cortisol, which at chronically elevated levels degrades muscle tissue, suppresses immune function, and impairs recovery. Rhodiola helps regulate the HPA (hypothalamic-pituitary-adrenal) axis, reducing the cortisol spike from training stress. A 2009 study in the Journal of Strength and Conditioning Research documented this effect in endurance athletes.

Improves time to exhaustion. Multiple studies have reported improvements in time to exhaustion at a fixed workload after rhodiola supplementation, with effect sizes ranging from 2 to 6%. For a competitive cyclist or runner, that margin matters.

Supports recovery between sessions. The cortisol-blunting effect has downstream benefits for inter-session recovery. Athletes in high-training-load blocks often report fewer "dead legs" days after starting a rhodiola protocol.

What Rhodiola Does NOT Do

This is important for setting the right expectations before you start.

It is not a stimulant. Rhodiola does not cause a caffeine-like energy boost. Some people report mild alertness, but this is not its primary mechanism and it varies by individual. If you take it and feel nothing acutely, that does not mean it is not working.

It does not work immediately. Most of the controlled studies showing performance benefits used supplementation periods of 4 to 6 weeks. The HPA-axis adaptation takes time to build. This is a chronic supplement, not a pre-race acute one.

It is not a replacement for training. Rhodiola helps you absorb and recover from a training load. It does not generate fitness in the absence of that load. The athletes who benefit most are those already training at high volumes.