Written by Jessica Patella, ND. Spirulina supplementation lengthened the time to the fatigue point by 24%.

Spirulina is a type of blue-green algae that is rich in amino acids, minerals, vitamin C and vitamin E (1,2). Spirulina also has antioxidant properties and has been shown to protect against oxidative damage from exercise (1). Recent research discovered spirulina supplementation increased exercise performance and fat oxidation.

The research included nine healthy male subjects aged 21.6 to 25 that were recreational runners and had been training for at least 1 year, twice per week and for at least 45 minutes per session. The subjects were not taking any supplements or anti-inflammatory drugs and diet diaries showed no significant caloric differences. (1).

The study was a double-blind, placebo-controlled, crossover design. In this type of study, neither the researchers nor the subjects knew if the subject was taking spirulina or placebo. Half of the subjects were given spirulina and the other half were given the placebo, followed by a washout period. The supplementation was then reversed; the subjects that were taking spirulina switched to the placebo and the subjects that were taking the placebo switched to spirulana.

A baseline VO2max was determined to ensure all the subjects exercised at a similar intensity. VO2max is a treadmill test used to determine the maximum amount of oxygen the body can transport and use during exercise.  After the baseline VO2max test, capsules of either spirulina or placebo were taken before meals three times per day for four weeks. The total daily dosage of spirulina was 6 grams (1). At the end of four weeks, the subjects returned for another VO2max test, followed by a 2-week washout period with no supplementation. Then the subjects that were taking spirulina took placebo for 4 weeks and vice versa. After the additional 4 weeks, a final VO2max test was taken.

The average intensity of exercise during the VO2 max test was similar for subjects, regardless of placebo (70.6 +/- 2.4%) or spirulina (71.0 +/- 1.9 %) (P> 0.05). Yet, the time to fatigue was significantly higher after spirulina supplementation (2.05 +/- 0.68 min vs. 2.70 +/- 0.79 min, P=0.048). Supplementation of spirulina also significantly increased the fat oxidation rate by 10.9% (P=0.003) compared to placebo (1).

In conclusion, spirulina supplementation for 4 weeks was associated with a significant increase in exercise performance and fat oxidation (1). It is possible the antioxidant properties of spirulina resulted in increased fat oxidation, which may have led to increased exercise performance. This is one of the first studies to supplement humans with spirulina and discover the relation to exercise performance. Further research, with more subjects, needs to be conducted to further understand the association between spirulina and exercise performance.

Source: Kalafati, Maria, et al. “Ergogenic and antioxidant effects of spirulina supplementation in humans.” Medicine & Science in Sports & Exercise 42.1 (2010): 142-151.

© 2009 by the American College of Sports Medicine

Posted January 25, 2011.


  1. Kalafati M, et al. Ergogenic and Antioxidant Effects of Spirulina Supplementation in Humans.  Med & Sci in Sports & Ex. 2009 DOI: 10.1249/MSS.0b013e3181ac7a45
  2. Spirulina.  University of Maryland Medical Center website.