Stress oxydatif et exercice physique

Revue générale. Mise en évidence du stress oxydatif au cours de l'exercice anaérobie. Comparaison exercices aérobies vs exercices anaérobies. Mécanismes supposés responsables de la production d'ERDO (espèces réactives dérivées de l'oxygène) et ERDA (espèces réactives dérivées de l'azote) lors de l'exercice anaérobie : auto-oxydation des catécholamines, augmentation de la consommation d'oxygène, activation de la xanthine oxydase et production d'hypoxanthin

Stress oxydatif, exercice de sprint et lactate

Numerous studies over the past few decades have demonstrated that aerobic exercise, if strenuous enough, induces an oxidative stress. Several factors may be involved in this free radical generation during aerobic exercise but the most important during such exercise is the important increase in oxygen consumption. Yet the effects of sprint anaerobic exercise on oxidative stress markers have not been fully clarified. Few studies have investigated this hypothesis and the existing data in humans are conflicting. Thus, the main purpose of this study was to detect an oxidative stress in human blood after a very brief and intense cycle-sprint exercise (the Wingate test) by measuring plasma lipid peroxidation markers (serum lipid radicals detected by ESR spectroscopy and plasma TBARS) and blood antioxidant system (SOD, GPx, GSH, uric acid and vitamin status). Lactate effect on free radical production and dietary antioxidant intake on oxidative stress induced by acute or chronic exercise will also be examinate. This study indicates that sprint anaerobic exercise increases lipid radical production and alteres the antioxidant status. However plasma TBARS is not a suitable marker in such exercise. Moreover, this study provides evidences that lactate ion, which is produced in a great amount during sprint exercise, may act as a good antioxydant. In vitro, it has been demonstrated to directly scavenge O2- and OH. Analysis of the daily antioxidant vitamin intake indicates a deficiency in antioxidant vitamin intake. This deficiency may be one explanation for the low plasma non-enzymatic antioxydant status observed at rest and may contribute to the alteration in plasma non-enzymatic antioxidant status in response to acute exercise. Finally, it seems that a low plasma non-enzymatic antioxidant status at rest increases the risk of chronic oxidative stress at rest, expecially in subjects who exibit a high phisical fitness level.De nombreux travaux ont démontré que l'exercice aérobie prolongé et exhaustif peut induire un stress oxydatif pour l'organisme (Dillard et coll., 1978, Lovlin et coll., 1987). Le principal facteur responsable est l'augmentation importante de la consommation d'oxygène dont une partie est déviée vers la formation d'espèces radicalaires. Les données concernant les effets d'un exercice bref et intense sollicitant le métabolisme anaérobie sont, chez l'homme, très rares et ne permettent pas de conclure (Marzatico et coll., 1997, Ortenblad et coll., 1997). L'objectif de ce travail est d'étudier l'effet d'un exercice bref et intense de 30-s (l'épreuve de Wingate) sur les marqueurs du stress oxydatif (radicaux lipidiques et TBARS) et sur le système sanguin antioxydant (SOD, GPx, GSH, acide urique et statut vitaminique). Il précise également le rôle du lactate dans l'apparition du SO induit par l'exercice ainsi que l'importance d'un apport satisfaisant en antioxydants dans la prévention du stress oxydatif induit par l'exercice aigu ou chronique. Ce travail montre qu'une épreuve de Wingate entraîne un stress oxydatif caractérisé par une surproduction de radicaux lipidiques et une altération du statut antioxydant sanguin. Le MDA, marqueur de la péroxydation lipidique classiquement utilisé dans l'exercice aérobie, n'est pas un bon indicateur du SO, dans ce cas. Le lactate, produit en grande quantité dans ce type d'exercice, n'intervient pas dans l'apparition des radicaux lipidiques puisqu'il exerce, in vitro, un effet antioxydant en piègeant l'anion superoxyde et le radical hydroxyle. Ce travail rapporte une carence d'apport en antioxydants dans la population sportive. Ces carences d'apport pourraient expliquer les faibles concentrations plasmatiques d'antioxydants non-enzymatiques observées, au repos, chez les sportifs et pourraient contribuer à accentuer l'altération du statut antioxydant plasmatique non-enzymatique, en réponse à l'exercice. Ce travail suggère enfin que l'altération du statut antioxydant plasmatique majore le risque de SO chronique au repos, et cela d'autant plus que l'aptitude physique des sujets est élevée.RENNES2-BU Centrale (352382101) / SudocSudocFranceF

Implication du stress oxydant dans la physiopathologie des maladies chroniques : intérêts de l'entrainement.

National audienceno abstrac

A Review of the Health-Promoting Properties of Spirulina with a Focus on athletes' Performance and Recovery

International audienceSpirulina species are photosynthetic and filamentous bacteria, commonly called 'blue-green microalgae'. Spirulina has a high nutrient content. It contains 60-70% protein with all essential amino acids present, and is rich in several vitamins, minerals, and bioactive compounds. Spirulina is also rich in essential fatty acids, and antioxidants. This rich nutritional content provides to Spirulina several health benefits including antioxidant, anti-inflammatory, immunomodulation, and insulin-sensitizing properties as well as positive effects in various diseases which could be also interesting for athletes. This paper mainly aims to review the interest and effects of Spirulina supplementation in athletes at rest, and in relation to exercise/training. Spirulina's biochemical composition, health properties/effects in humans, and effects in athletes including nutritional status, body composition, physical performance and intense exercise-related disorders were discussed in this review. Literature data showed that Spirulina seems to have positive effects on body composition especially in overweight and obese subjects which could not be the case in other pathologies and athletes. Spirulina appears to be also effective in improving aerobic fitness especially in untrained and moderately trained subjects. Results reported in the literature suggest that Spirulina may improve strength and power performance despite the minor or no significant effects in highly trained subjects. Most studies have shown that Spirulina improves antioxidant status, prevents and accelerates the recovery of exercise-induced lipid peroxidation, muscle damage and inflammation in trained and untrained subjects. Taken together, the results from these studies are encouraging and may demonstrate the potential benefits of Spirulina supplementation in athletes despite methodological differences

Physiologie du sport et de l'exercice

Traduction française de l'ouvrage américain "Physiology of Sport and Exercise" de JH Costill et DL Wilmore aux éditions De Boe

High intensity training and salivary immunoglobulin: a responses in professional top-level soccer players: effect of training intensity

This study aimed 1)- to test the hypothesis that salivary immunoglobulin A (s-IgA) would vary with training intensity sessions (low intensity [LI] vs. high intensity sessions [HI]) during a traditional training program divided in 4 training periods and 2)- to identify key variables (e.g. GPS data, RPE, training duration) which could affect s-IgA. Saliva samples of 10 elite professional soccer players were collected a)- before the investigation started to establish the baseline level, b)-before and after each 4 training sessions (LI vs. HI). Training intensity was monitored as internal (via heart rate responses and RPE) and external (via GPS) loads. HI sessions were associated with higher external load (GPS) and with higher RPE. Baseline and Pre-Training s-IgA did not differ between the 4 training sessions both for HI and LI. Post-Training s-IgA were not different (in absolute value and in percentage of change) between HI and LI sessions at the first three periods. However, at the fourth period, s-IgA concentration for HI session was significantly lower (p\u3c0.05) than the LI session. The percentage change between s-IgA post-training and s-IgA baseline concentrations differ significantly (p\u3c0.05) between HI and LI training sessions. Significant correlations between s-IgA and training intensity were also noted. HI soccer training sessions might cause a significant decrease in s-IgA values during the post-exercise window as compared with LI sessions. This study encourages coaches to monitor s-IgA in routine particularly during HI training periods to take precautions to avoid upper respiratory tract infection in highly trained soccer players