Spirulina for Exercise Performance

Research suggests that spirulina supplementation may offer some benefits for exercise performance, particularly in the areas of aerobic capacity, submaximal exercise efficiency, and oxidative stress management. Two randomized controlled trials found that spirulina increased hemoglobin levels, improved peak oxygen uptake, extended time to exhaustion, and shifted fuel use toward greater fat oxidation during exercise, while a rat study found complementary molecular evidence suggesting spirulina may support muscle adaptation and mitochondrial function when combined with endurance training. However, review-level evidence characterizes the overall picture as mixed — early findings relied on oxidative stress biomarkers now considered unreliable, effect sizes across studies tend to be small, proposed mechanisms remain unconfirmed, and large rigorous randomized controlled trials in humans are still lacking. The available evidence base, while directionally promising, is limited in scope and consistency, and broader, more methodologically robust research is needed before firm conclusions can be drawn about spirulina's role in supporting athletic performance.