Purpose: Spirulina is a popular nutritional supplement that is accompanied by claiMSS for antioxidant and performance-enhancing effects. Therefore, the aim of the present study was to examine the effect of spirulina supplementation on (i) exercise performance, (ii) substrate metabolism, and (iii) blood redox status both at rest and after exercise.
Methods: Nine moderately trained males took part in a double-blind, placebo-controlled, counterbalanced crossover study. Each subject received either spirulina (6 g·d−1) or placebo for 4 wk. Each subject ran on a treadmill at an intensity corresponding to 70%-75% of their V˙O2max for 2 h and then at 95% V˙O2max to exhaustion. Exercise performance and respiratory quotient during exercise were measured after both placebo and spirulina supplementation. Blood samples were drawn before, immediately after, and at 1, 24, and 48 h after exercise. Reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG, thiobarbituric acid-reactive substances (TBARS), protein carbonyls, catalase activity, and total antioxidant capacity (TAC) were determined.
Results: Time to fatigue after the 2-h run was significantly longer after spirulina supplementation (2.05 ± 0.68 vs 2.70 ± 0.79 min). Ingestion of spirulina significantly decreased carbohydrate oxidation rate by 10.3% and increased fat oxidation rate by 10.9% during the 2-h run compared with the placebo trial. GSH levels were higher after the spirulina supplementation compared with placebo at rest and 24 h after exercise. TBARS levels increased after exercise after placebo but not after spirulina supplementation. Protein carbonyls, catalase, and TAC levels increased similarly immediately after and 1 h after exercise in both groups.
Conclusions: Spirulina supplementation induced a significant increase in exercise performance, fat oxidation, and GSH concentration and attenuated the exercise-induced increase in lipid peroxidation.
1Institute of Human Performance and Rehabilitation, Center for Research and Technology - Thessaly, Trikala, GREECE; 2Department of Physical Education and Sport Science, University of Thessaly, Trikala, GREECE; 3School of Sport, Performing Arts and Leisure, Wolverhampton University, Walshall, UNITED KINGDOM; and 4Department of Biochemistry & Biotechnology, University of Thessaly, Larissa, GREECE
Address for correspondence: Athanasios Z. Jamurtas, Ph.D., Department of Physical Education and Sports Sciences, University of Thessaly, Karies, 42100, Trikala, Greece; E-mail: email@example.com.
Submitted for publication November 2008.
Accepted for publication April 2009.