Dietary Supplements and Sport Performance - A Comprehensive Review

  • Julij Šelb University Clinic of Respiratory and Allergic Diseases Golnik
  • Helena Lenasi* University of Ljubljana, Faculty of Medicine, Institute of Physiology, Ljubljana, Slovenia


Aim: Comprehensive articles on dietary supplements and their impact on sport performance, which would provide professional and recreational athletes with evidence-based information, are sparse. Methods: Investigation involved eight different dietary supplements, commonly used among recreational and endurance athletes according to available literature obtained by searching the PubMed database, namely:Antioxidants, beta-alanine (B-alanine), branched-chain amino acids (BCAAs), caffeine, carbohydrates, creatine, nitric oxide/nitrates, and proteins. Their mechanisms of action have been briefly presented, along with their potential beneficial and harmful side effects and safety. Results: i.)Antioxidants: A sufficient amount of antioxidants is available in a balanced diet ii.)B-alanine: Supplementation is likely to be beneficial in high-intensity exercises. iii.)BCAAs: No review articles in English were available iv.)Caffeine: Caffeine supplementation is beneficial in endurance exercises v.) Carbohydrates: Carbohydrate supplementation is probably beneficial in exercises lasting longer than one hour vi.) Creatine: Creatine supplementation is effective in high intensity, short-lasting exercise, while it does not seem to have any ergogenic effect in aerobic exercise. vii.) Nitric oxide/nitrates: Nitrate supplementation has a small but significant performance-enhancing effect, most apparently in situations of insufficient perfusion. viii.) Proteins: Protein supplementation, in combination with resistance exercise, most likely has beneficial effects on lean body mass and muscle strength. Conclusion: Most of the analyzed dietary supplements, if used for intended exercise regime, provide a kind of sport performance enhancement. On the other hand, long-term studies about their safety are mostly lacking. term studies about their safety are mostly lacking.   Keywords: dietary supplements, sports, endurance, performance-enhancing substances