Spirulina supplementation induced a significant increase in exercise performance, fat oxidation and glutathione (GSH) concentration, and attenuated the exercise-induced increase in lipid peroxidation, according to an article published in Medicine & Science in Sports & Exercise (2010;42(1):142-151). Nine moderately trained males took part in a double blind, placebo-controlled, counterbalanced crossover study. Each subject received either 6 g/d of spirulina or placebo for four weeks. Each subject ran on a treadmill at an intensity corresponding to 70 percent to75 percent of their VO2max for two hours0 and then at 95 percent VO2max to exhaustion.

Time to fatigue after the two-hour run was significantly longer after spirulina supplementation. Ingestion of spirulina significantly decreased carbohydrate oxidation rate by 10.3 percent and increased fat oxidation rate by 10.9 percent during the two-hour run compared with the placebo trial. GSH levels were higher after the spirulina supplementation compared with placebo at rest and 24 hours after exercise. Thiobarbituric acid-reactive substances (TBARS) levels increased after exercise after placebo but not after spirulina supplementation. Protein carbonyls, catalase and total antioxidant capacity levels increased similarly immediately after and one hour after exercise in both groups.