Effect of glutathione supplementation on swimmers’ performance

Keywords: glutathione, supplements, elite, swimming, performance


Background and Study Aim. Continuously increasing the volume and intensity of the training sessions often leads to overtraining. It has been demonstrated that glutathione supplementation might improve the aerobic metabolism in skeletal muscle and reduce exercise-induced muscle fatigue. The aim of the study was to assess the effect of glutathione supplementation on fatigue, recovery processes, and competitive results of elite swimmers during a six-week training period. Material and Methods. Twenty-four elite swimmers (10 women and 14 men) from the Bulgarian national swimming team, with a mean age of 18.7±3.78 years, took part in this double-blind placebo control study. The swimmers from the experimental group were supplemented once a day with a capsule of 250mg glutathione, whilst the swimmers from the control group took a placebo once a day. The urine concentration levels of cortisol and cortisone, as well as the degree of overtraining, were evaluated on the 1st(T1), 14th(T2), 28th(T3), and 42nd(T4) days. Anthropometric measurements and a nutritional assessment were performed at T1 and T4. Results. The swimmers showed a gradual decrease of cortisol and cortisone during the study, with significantly lower concentrations in the experimental vs the control group at T4 (19.4 vs 42.5 ng/mL, p < 0.05). At the end of the study, the swimmers from the experimental group showed improvements in their time in 41 out of the 43 swimming events, whilst those from the control group had significantly smaller improvements (-1.66 vs -0.97%, p < 0.05). Conclusions. In conclusion, glutathione supplementation at a dose of 250mg/day for six weeks improves the adaptation of elite swimmers towards training schedules, which is likely to lead to better sports results.


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Author Biographies

Lubomir Petrov, National Sports Academy
dr.lubomir.petrov@gmail.com; National Sports Academy; Sofia, Bulgaria.
Albena Alexandrova, National Sports Academy
a_alexandrova_bas@yahoo.com; National Sports Academy; Sofia, Bulgaria.
Mihail Kachaunov, National Sports Academy
mihail.kachaunov@gmail.com; National Sports Academy; Sofia, Bulgaria.
Radoslav Penov, National Sports Academy
fighters.nsa@abv.bg; National Sports Academy; Sofia, Bulgaria.
Tanya Sheytanova, National Sports Academy
tanyasheytanova@mail.bg; National Sports Academy; Sofia, Bulgaria.
Stefan Kolimechkov, STK Sport
dr.stefan.kolimechkov@gmail.com; STK SPORT; London, United Kingdom.


1. O'Connor PJ, Morgan WP, Raglin JS, Barksdale CM, Kalin NH. Mood state and salivary cortisol levels following overtraining in female swimmers. Psychoneuroendocrinology. 1989;14(4):303–10.

2. Morgan WP, Brown DR, Raglin JS, O'Connor PJ, Ellickson KA. Psychological monitoring of overtraining and staleness. Br J Sports Med. 1987;21(3):107–14.

3. Hooper SL, MacKinnon LT, Hanrahan S. Mood states as an indication of staleness and recovery. International Journal of Sport Psychology. 1997;28(1):1–12.

4. Mateu P, Ingles E, Torregrossa M, Marques RFR, Stambulova N, Vilanova A. Living Life Through Sport: The Transition of Elite Spanish Student-Athletes to a University Degree in Physical Activity and Sports Sciences. Frontiers in Psychology. 2020;11.

5. Goldhaber JI, Qayyum MS. Oxygen free radicals and excitation-contraction coupling. Antioxidants & redox signaling. 2000;2(1):55–64.

6. Reid MB. Nitric oxide, reactive oxygen species, and skeletal muscle contraction. Med Sci Sports Exerc. 2001;33(3):371–6.

7. Joro R, Korkmaz A, Lakka TA, Uusitalo ALT, Atalay M. Plasma irisin and its associations with oxidative stress in athletes suffering from overtraining syndrome. Physiology International. 2020;107(4):513–526.

8. Luti S, Modesti A, Modesti PA. Inflammation, Peripheral Signals and Redox Homeostasis in Athletes Who Practice Different Sports. Antioxidants. 2020;9(11).

9. Gougoura S, Nikolaidis MG, Kostaropoulos IA, Jamurtas AZ, Koukoulis G, Kouretas D. Increased oxidative stress indices in the blood of child swimmers. European Journal of Applied Physiology. 2007;100(2):235–9.

10. Koivisto AE, Olsen T, Paur I, Paulsen G, Bastani NE, Garthe I, et al. Effects of antioxidant-rich foods on altitude-induced oxidative stress and inflammation in elite endurance athletes: A randomized controlled trial. Plos One. 2019;14(6).

11. Michalickova D, Minic R, Kotur-Stevuljevic J, Andjelkovic M, Dikic N, Kostic-Vucicevic M, et al. Changes in Parameters of Oxidative Stress, Immunity, and Behavior in Endurance Athletes During a Preparation Period in Winter. Journal of Strength and Conditioning Research. 2020;34(10):2965–2973.

12. Souissi W, Bouzid MA, Farjallah MA, Ben Mahmoud L, Boudaya M, Engel FA, et al. Effect of Different Running Exercise Modalities on Post-Exercise Oxidative Stress Markers in Trained Athletes. International Journal of Environmental Research and Public Health. 2020;17(10).

13. Zhang H, Forman HJ. Glutathione synthesis and its role in redox signaling. Seminars in cell & developmental biology. 2012;23(7):722–-8.

14. Kidd PM. Glutathione: Systemic protectant against oxidative and free radical damage. Alternative Medicine Review. 1997;2:155–76.

15. Griffith OW. Biologic and pharmacologic regulation of mammalian glutathione synthesis. Free Radical Biology & Medicine. 1999;27(9-10):922–35.

16. Powers SK, Jackson MJ. Exercise-induced oxidative stress: cellular mechanisms and impact on muscle force production. Physiological reviews. 2008;88(4):1243–76.

17. Ji L, La J. Antioxidant defense:effects of aging and exercise. In: Radak Z, editor. Free Radicals in Exercise and Aging. Champaign, IL: Human Kinetics; 2000. P. 35–72.

18. Brigelius-Flohe R, Maiorino M. Glutathione peroxidases. Biochimica et Biophysica Acta. 2013;1830(5):3289–303.

19. Jones DP, Carlson JL, Mody VC, Cai J, Lynn MJ, Sternberg P. Redox state of glutathione in human plasma. Free Radical Biology & Medicine. 2000;28(4):625–35.

20. Owen JB, Butterfield DA. Measurement of Oxidized/Reduced Glutathione Ratio In: Bross P, Gregersen N, editors. Protein Misfolding and Cellular Stress in Disease and Aging. Totowa, NJ: Humana Press; 2010.

21. Kaplowitz N, Aw TY, Ookhtens M. The regulation of hepatic glutathione. Annual Review of Pharmacology and Toxicology. 1985;25:715–44.

22. Wu G, Fang YZ, Yang S, Lupton JR, Turner ND. Glutathione metabolism and its implications for health. The Journal of Nutrition. 2004;134(3):489–92.

23. de Oliveira DCX, Rosa FT, Simoes-Ambrosio L, Jordao AA, Deminice R. Antioxidant vitamin supplementation prevents oxidative stress but does not enhance performance in young football athletes. Nutrition. 2019;63-64:29–35.

24. Zanella PB, August PM, Alves FD, Matte C, de Souz CG. Association of Healthy Eating Index and oxidative stress in adolescent volleyball athletes and non-athletes. Nutrition. 2019;60:230–234.

25. Gohil K, Viguie C, Stanley WC, Brooks GA, Packer L. Blood glutathione oxidation during human exercise. Journal of Applied Physiology, 1988;64:115–9.

26. Laires MJ, Madeira F, Sergio J, Colaco C, Vaz C, Felisberto GM, et al. Preliminary study of the relationship between plasma and erythrocyte magnesium variations and some circulating pro-oxidant and antioxidant indices in a standardized physical effort. Magnesium Research. 1993;6(3):233–8.

27. Viguie CA, Frei B, Shigenaga MK, Ames BN, Packer L, Brooks GA. Antioxidant status and indexes of oxidative stress during consecutive days of exercise. Journal of Applied Physiology, 1993;75:566–72.

28. Kretzschmar M, Muller D. Aging, training and exercise. A review of effects on plasma glutathione and lipid peroxides. Sports Med. 1993;15(3):196–209.

29. Tessier F, Margaritis I, Richard MJ, Moynot C, Marconnet P. Selenium and training effects on the glutathione system and aerobic performance. Med Sci Sports Exerc. 1995;27(3):390–6.

30. Sastre J, Asensi M, Gasco E, Pallardo FV, Ferrero JA, Furukawa T, et al. Exhaustive physical exercise causes oxidation of glutathione status in blood: prevention by antioxidant administration. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 1992;263:R992–5.

31. Paschalis V, Theodorou AA, Margaritelis NV, Kyparos A, Nikolaidis MG. N-acetylcysteine supplementation increases exercise performance and reduces oxidative stress only in individuals with low levels of glutathione. Free Radical Biology & Medicine. 2018;115:288–97.

32. Kerksick CM, Kreider RB, Willoughby DS. Intramuscular adaptations to eccentric exercise and antioxidant supplementation. Amino Acids. 2010;39(1):219–32.

33. Slattery KM, Dascombe B, Wallace LK, Bentley DJ, Coutts AJ. Effect of N-acetylcysteine on cycling performance after intensified training. Med Sci Sports Exerc. 2014;46(6):1114–23.

34. Antonioni A, Fantini C, Dimauro I, Caporossi D. Redox homeostasis in sport: do athletes really need antioxidant support? Res Sports Med. 2019;27(2):147–165.

35. Whillier S, Raftos JE, Chapman B, Kuchel PW. Role of N-acetylcysteine and cystine in glutathione synthesis in human erythrocytes. Redox Report: Communications in Free Radical Research. 2009;14(3):115–24.

36. Witschi A, Reddy S, Stofer B, Lauterburg BH. The systemic availability of oral glutathione. European Journal of Clinical Pharmacology. 1992;43(6):667–9.

37. Allen J, Bradley RD. Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers. Journal of Alternative and Complementary Medicine. 2011;17(9):827–33.

38. Favilli F, Marraccini P, Iantomasi T, Vincenzini MT. Effect of orally administered glutathione on glutathione levels in some organs of rats: role of specific transporters. The British Journal of Nutrition. 1997;78(2):293–300.

39. Hagen TM, Wierzbicka GT, Bowman BB, Aw TY, Jones DP. Fate of dietary glutathione: disposition in the gastrointestinal tract. American Journal of Physiology-Gastrointestinal and Liver Physiology, 1990;259:G530–5.

40. Kovacs-Nolan J, Rupa P, Matsui T, Tanaka M, Konishi T, Sauchi Y, et al. In vitro and ex vivo uptake of glutathione (GSH) across the intestinal epithelium and fate of oral GSH after in vivo supplementation. Journal of Agricultural and Food Chemistry. 2014;62(39):9499–506.

41. Park EY, Shimura N, Konishi T, Sauchi Y, Wada S, Aoi W, et al. Increase in the protein-bound form of glutathione in human blood after the oral administration of glutathione. Journal of Agricultural and Food Chemistry. 2014;62(26):6183–9.

42. Aoi W, Ogaya Y, Takami M, Konishi T, Sauchi Y, Park E, et al. Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism. J Int Soc Sports Nutr, 2015;12:7.

43. Correia JC, Ferreira DMS, Ruas JL. Intercellular: local and systemic actions of skeletal muscle PGC-1s. Trends in Endocrinology & Metabolism, 2015;26:305–14.

44. World Medical Association Declaration of Helsinki: Ethical Principles for Medical Research Involving Human Subjects. JAMA, 2013;310:2191.

45. Maglischo E. Swimming fastest. Human Kinetics; 2003.

46. Jackson AS, Pollock ML. Generalized equations for predicting body density of men. The British Journal of Nutrition. 1978;40(3):497–504.

47. Lee RC, Wang Z, Heo M, Ross R, Janssen I, Heymsfield SB. Total-body skeletal muscle mass: development and cross-validation of anthropometric prediction models. Am J Clin Nutr. 2000;72(3):796–803.

48. Miteva S, Yanev I, Kolimechkov S, Petrov L, Mladenov L, Georgieva V, et al. Nutrition and body composition of elite rhythmic gymnasts from Bulgaria. International Journal of Sports Science & Coaching. 2020;15(1):108–16.

49. Kolimechkov S, Yanev I, Kiuchukov I, Petrov L, Alexandrova A, Zaykova D, et al. Nutritional status and body composition of young artistic gymnasts from Bulgaria. Journal of Applied Sports Sciences. 2019;1:39–52.

50. US Department of Agriculture. Agricultural Research Service, Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference, Release 28. Version Current: September 2015, slightly revised May 2016; 2015.

51. STK-SPORT. Food Frequency Questionnaire [Internet]. 2020 [updated 2020 Jun 15; cited 2020 Nov 30]. Available from: https://www.stk-sport.co.uk/food-frequency-questionnaire.html

52. Harris J, Benedict F. A Biometric Study of Basal Metabolism in Man. Washington DC: Carnegie Institute of Washington; 1919. P. 1–266.

53. Grove JR, Main LC, Partridge K, Bishop DJ, Russell S, Shepherdson A, et al. Training distress and performance readiness: laboratory and field validation of a brief self-report measure. Scandinavian Journal of Medicine & Science in Sports. 2014;24(6):e483– 90.

54. Boudreau C. Nutrition: Fueling for Performance. Riewald S, Rodeo S, editors. Science of Swimming Faster. Human Kinetics; 2015.
How to Cite
Petrov L, Alexandrova A, Kachaunov M, Penov R, Sheytanova T, Kolimechkov S. Effect of glutathione supplementation on swimmers’ performance. Pedagogy of Physical Culture and Sports. 2021;25(4):215-24. https://doi.org/10.15561/26649837.2021.0403