The omega-3 index measures EPA plus DHA in red blood cells. Athletes average 4.4%, and fish oil lowers heart rate and oxygen cost but has not been shown to improve endurance performance.

Fish oil is often recommended after injury. This blog looks at what the studies show for muscle loss during immobilisation, muscle soreness and concussion.

A systematic review of 32 trials found that fish oil supplements affect muscle recovery, mood and reaction time in athletes, but not endurance performance or training adaptations.

What are omega-3 fatty acids, why can the body not make all it needs, and which foods and supplements provide ALA, EPA and DHA? A short explainer on fish oil and omega-3 sources.