Controversies The differences between the results in the studies described can also be mainly attributed to the different Hedgehog inhibitor methodologies, conveyed vitamin dosage, study length, sample size, differences in gender, age, and subjects characteristics (athletes and non-athletes). These differences make it difficult to draw conclusion about the advantages and disadvantages of antioxidant vitamins supplementation. So far, the results of the studies presented confirm that exercise is capable of increasing the oxidative

capacity of skeletal muscle and potentiate the action of endogenous antioxidants [6]. Exercise increases the expression of reduced glutathione (GSH) and antioxidant enzymes (superoxide dismutase [SOD], and glutathione VX-689 peroxidase [GSH-Px]), which appear to be sufficient to counteract the negative effects of exercise-induced oxidative click here stress [3, 7, 8]. In this context, the real need to use antioxidant vitamins supplements as ergogenic aids is questionable. The safest and effective alternative in attenuating exercise-induced oxidative stress could be a balanced diet based on foods with the recommended amounts of antioxidants in order to improve exercise performance. Conclusions The results obtained in the considered studies with antioxidant vitamins supplementation are contradictory. Some studies show

that supplementation does not improve exercise performance but can impair it. Others show that supplementation provides a slight advantage

over the placebo. Thus, although many athletes use antioxidant supplementation to improve their physical performance, Casein kinase 1 there is no consistent evidence suggesting that supplementation reduces oxidative stress and ensures better results in exercise. References 1. Halliwell B: The wanderings of a free radical. Free Radic Biol Med 2009, 46:531–542.PubMedCrossRef 2. Chaput JP, Klingenberg L, Rosenkilde M, Gilbert JA, Tremblay A, Sjodin A: Physical activity plays an important role in body weight regulation. J Obes 2011, 2011:11.CrossRef 3. Ristow M, Zarse K, Oberbach A, Kloting N, Birringer M, Kiehntopf M, Stumvoll M, Kahn CR, Bluher M: Antioxidants prevent health-promoting effects of physical exercise in humans. Proc Natl Acad Sci USA 2009, 106:8665–8670.PubMedCentralPubMedCrossRef 4. Sahlin K, Shabalina IG, Mattsson CM, Bakkman L, Fernstrom M, Rozhdestvenskaya Z, Enqvist JK, Nedergaard J, Ekblom B, Tonkonogi M: Ultraendurance exercise increases the production of reactive oxygen species in isolated mitochondria from human skeletal muscle. J Appl Physiol (1985) 2010, 108:780–787.CrossRef 5. Yfanti C, Fischer CP, Nielsen S, Akerstrom T, Nielsen AR, Veskoukis AS, Kouretas D, Lykkesfeldt J, Pilegaard H, Pedersen BK: Role of vitamin C and E supplementation on IL-6 in response to training. J Appl Physiol (1985) 2012, 112:990–1000.CrossRef 6.