Effet de l'entraînement sur la désaturation de l'oxyhémoglobine au cours d'une saison sportive chez le triathlète

Introduction – Endurance athletes frequently present an exercise induced hypoxemia at sub-maximal or maximal exercise.Methods – The results of a recent study that compared two groups of highly trained athletes, one with exercise induced hypoxemia and the other without, suggested that a difference in training volume (4 hours per week) and/or training intensity may explain the difference in the exercise-induced hypoxemia observed. The aim of the study was to evaluate the effects of volume and/or intensity of training on exercise induced desaturation in triathletes during a competitive season.Conclusions – This study showed that exercise induced desaturation was related to both volume and intensity of training in triathletes.     

Évolution de la puissance maximale anaérobie au cours de la croissance chez le footballeur

Purpose – The aim of the study was to assess the improvement in Maximal Anaerobic Power (PMAna) from two tests in soccer players during growth.Methods – The experiment was carried out in 328 players, 11–18 years old, during their stay at the Clairefontaine National Soccer Center. PMAna was measured from the last 10 meters of the a 40 m-sprint test (ST) and a jump test (JT). The skeletal age (AO) is used as reference, and not the chronological one.Results – The results of the two tests are highly correlated (r= 0.8–0.9), PMAna values being always higher in the ST than in the JT.The most significant increase in PMAna occurs between 13 and 14 years AO (+47% for the ST, +27% for the JT), remains still significant up to 16 AO (respectively +38% and +24% between 14 and 16 AO), but the maximum value is reached at 17 AO. Between 12 and 16 AO, the PMAna value is multiplied by 2.29 for the ST and 1.81 for the JT.Conclusions – Sprint and jump tests seem well adapted to estimate PMAna in soccer players. The measure of the skeletal age during growth is needed for a better interpretation of the results. In addition, results obtained during growth allow a reliable estimation of PMAna in adulthood.     

Estimation de la contribution énergétique d'origine aérobie et anaérobie et de sa répartition au cours d'un 800 m couru sur le mode compétition

Aim – Determine the part of each energetic system at different times of 800m competition. Oxygen uptake and speed were recorded continuously.Materials and methods – Five athletes performed on an outdoor track a test to determine the maximal oxygen uptake and the maximal aerobic speed and a supramaximal exercise of 800m.Results – The overall energetic expenditure as well as the oxygen deficit assessed at 31.9% were almost identical at those obtained during an 800m race running on a treadmill. Only the repartition of the oxygen deficit notably differed during the race. This suggered that the kinetic of the speed had a determining incidence on the anaerobic contribution as well as aerobic contribution when there were changes in running velocity.     

Réponses du cortisol et de la testostérone salivaires au cours de la récupération post-compétitive en rugby

Aim. – In order to evaluate the biological repercussions of the post-competitive tiredness state, we measured the progress of the salivary cortisol and testosterone levels in the players of a rugby-team during the week following an international match.Results. – The results reveal a fall of the cortisol levels during the first 4 days following the competition, compared to the values measured at the same hour of a resting day. Conversely, the testosterone levels present an increase during the same period. Consequently, 5 days of recovery are needed for these two biological variables chosen as tiredness markers to return to their basic values.     

Adaptations métaboliques à l'entraînement en début de saison de natation. Différences en fonction du sexe

Purpose – In this study, we compared the early metabolic adaptations to swim training between healthy men (n = 7) and women (n = 8).Methods – On the 1^st, 3^rd and 5^th testing sessions, plasma Fourier-transform infrared (FT-IR) spectra were obtained at the resting state and after each standardized testing session.Results – At the 1^st testing session, glycemia decreased more in females than in males (respectively, –1.101, –0.687 mmol.l^–1), triglycerides (TG) increased in females (0.184 mmol/l) and decreased in males (–0.094 mmol.l^–1) and males presented a higher plasma urea increase (p < 0.05). At the third testing session, glycemia increased in females (0.458 mmol.l^–1) whereas it decreased in males (–0.601 mmol.l^–1). Plasma urea increased more in males compared to females during exercise (p < 0.01). On the other hand, Apo B increased in females (0.063 g.l) and decreased in males (–0.073 g.l^–1) during exercise. At the 5^th testing session, males and females exhibited an equivalent metabolic response to exercise. However, IgA, IgG₁, IgG₃ and IgM were significantly different during exercise in males and females (p < 0.01) throughout the three sessions.Conclusions – Indeed, although metabolic adaptations to early phases of swim training were different, male and female subjects finally exhibited the same global metabolic response to endurance exercise. However immunity response to exercise in women and men was different throughout the three testing sessions.