Évaluation des masses musculaires et des densités osseuses régionales chez des kayakistes de haut niveau

Aim. – To determine the body composition and bone densities in elite teenagers kayak paddlers.Materials and methods. – The population consisted of 14 boys (seven kayak paddlers and seven controls). The training frequency of kayak paddlers was 10 h/week when the control group had less than 4 h/week of physical activity. The body composition and bone density were measured by DXA.Conclusion. – The intensive kayak training seems to improve lean body mass and bone density at the specific sites involved in this activity (arms, trunk).     

Exigences physiologiques nécessaires à la pratique de rugby de haut niveau

Introduction – The objective of our work is to determine physiological features of rugby players of French team.Synthesis of facts – We realized the physical tests for estimate of maximal oxygen uptake (VO₂max), lactate anaerobic, Sargent, explosive strength on ergojump and supple. The results showed that aerobic power and lactate anaerobic were favourable of back. The performances of back of ergojump and Sargent were better than these forward. It not existed significant difference of supple between forward and black.Conclusion – The physical tests bring to the fore different athletes not only on the morphological and metabolic plane but also on the powerful and supple plane.     

Étude épidémiologique du risque traumatique des footballeurs français de haut niveau

The association of French professional football undertook a 18 months epidemiological study. Player injuries (more than 7 days) were noticed by physicians. Eleven clubs during 6 months and 10 clubs during one season participated in the study. The injury incidence varied throughout the season and with teams. The peak of injuries was noticed before the season, in November, and between February and March. Training injuries were very low. Strains and sprains (ankle and knee), were the major injury types. We noticed a dramatic increase of hamstring lesions for the field players. Rupture of achille tendon represented 15% of all tendon lesions (with more than 90 days for absence). Reinjuries were correlated with total number of injuries, in regard with bad cicatrisation and poor rehabilitation protocols. Professional football players are exposed to a high risk of injury during the matches. Most attention must be pointed about prevention, training programs and rehabilitation time.     

Caractéristiques physiques et physiologiques de cyclistes professionnels

Introduction. – We aimed to characterize the physical capacities of a population of professional cyclists using anthropometrical, cardiovascular, respiratory, ventilatory, and energetic measures.Synthesis of facts. – Eight professional cyclists participated in this study. They performed over 1 day, 5 exercises (progressive and constant-load test) on a cyclo-ergometer.Conclusions. – Physical and physiological results confirmed previous observations done on professional cyclists. The values of maximal power tolerated and time to exhaustion at this power are reproducible during the day thus demonstrated the excellent capability to recover of the professional cyclists.     

Évaluation de l'état de stress oxydatif chez des footballeurs et des basketteurs professionnels

Aim – Evaluation of oxidative stress status.Methods and results – Mean values in antioxidant vitamins, sulphydryl proteins and selenium were found to be in a normal range in the blood of top soccer (n=21) and basketball (n=9) players at the end of half a season of regular training and competititon. Glutathion peroxidase levels were higher than the mean superior value in fourteen players, suggesting a possible adaptation to oxidative stress induced by physical exercise.Conclusion – Despite an apparent normal antioxidant status, the presence of such an oxidative stress is confirmed in half of the players as evidenced by elevated levels in autoantibodies against oxidized lipoproteins.     

Évolution de la lactatémie lors d'une séance de vitesse chez des sprinters de niveau national

Aim – We measured in this work the plasma lactate concentrations in male sprinters competing at national level after repetitions of 50 m sprint at maximal speed on the track.Results – Plasma lactate concentration increases significantly after the first repetition of sprint, from 3.9 ± 0.1 mmol.l⁻¹ before the first sprint to 14.0 ± 3.0 mmol.l⁻¹ observed after the 3th repetition.Discussion and conclusion – Our results confirmed that the activity of the lactic anaerobic metabolism reflected by plasma lactate concentration is very high during the first seconds of sprint exercises below seven seconds. Sprint coaches must take into account these data when they program sprint sessions.     

Influence des caractéristiques de la natation sur la performance lors d’un enchaînement natation–cyclisme

Purpose. – Investigate the influence of previous swimming on energy expenditure during the subsequent cycling exercise of a triathlon.Methods. – Ten well trained triathletes underwent 3 swim-to-cycle transitions and 1 isolated cycling trial (C trial). The cycling exercises consisted in 15 min on a bicycle ergometer at a power output corresponding to the ventilatory threshold +5 %. During the transitions, this exercise was preceded by swimming bouts soliciting different muscles, undertaken at a 750 m competition pace for the same duration (swimming with arms and legs: Sal trial, with arms only: SA trial, or with legs only: SL trial).Résultats. – The swimming bouts of SA and Sal trials involved a significant increase in energy expenditure during subsequent cycling in comparison with isolated cycling (P < 0.05). Moreover, cycling efficiency was not significantly different between SA and SAL trials (P > 0.05).Conclusion. – A short intense swimming leads to an increase in energy expenditure during subsequent cycling, because of the thermoregulatory adjustments and the additional oxygen cost of respiratory work involved during swimming. It also shows that physiological adaptation during cycling does not depend on the lower limb work during prior swimming.     

Statut biologique,hormonal, nutritionnel et psychologique de gymnastes féminines de haut niveau

Introduction – Biological, hematological, nutritional, psychological parameters and hormone productions from the gonadotropic, somatotropic, and adrenocorticotropic axis have been examined in seven international level gymnasts (14.5 ± 1.2 years) from a National Gymnastic Institute.Methods – To explore the hormonal, biological and metabolic characteristics of the gymnasts resting blood samples were collected from an antecubital vein (700 hours) after an overnight fast. Anthropometric data, food intake and psychological data were also collected.Results – The gymnasts were below the standard for both weight and stature. No gymnast reached the menarche. The puberty stage corresponded to stage P2. The mean level of LH, FSH, SDHEA, Testosterone, and androstenedione secretion corresponded to the stage P4–P5. On the other hand, oestradiol and progesterone levels showed rates corresponding to the P2 stage. The values of IGF-1 and IGF-BP-3 approached the high standards. The osteocalcin presented values much higher than the normal. The hemogramm corresponded to the standards. Lipid values corresponded with that of girls of the same age group. Energy intake Daily energy intake met daily energy requirement. The studied psychological parameters reflect a state of mental stress.Conclusion – Our results suggested that the gonadal axis is more sensitive to the training than the pituitary-adrenal axis. A longitudinal follow-up of these parameters will be necessary in order to examine the impact of the training load on these parameters.     

Évolution du seuil ventilatoire pendant la croissance. Relations avec les caractéristiques anthropométriques. Étude multilongitudinale. (Définition de valeurs de références)

Aims – Specify the changes in ventilatory threshold during growth, determine what parts of the changes are due to anthropometric characteristics and, define reference values for ventilatory threshold during growth in health sedentary boys aged 11–17 years.Methods – This study was conducted in 49 untrained schoolboys separated into three groups, with an initial age of 11.2±0.7 years for group A (n=23), 13±2.1 years for group B (n=15), 15±3.9 years for group C (n=11). These children were subsequently followed for 3 years. Every years, during the same time period, the children performed a maximal exercice test on bicycle ergometer in their schools. Maximal oxygen uptake and ventilatory threshold were measured.Results and conclusion – Our study showed no significant changes with age in ventilatory threshold expressed in percent of maximal oxygen uptake: oxygen uptake at the ventilatory threshold and maximal oxygen uptake similarly increased during growth. The study of the linear correlations between oxygen uptake at the ventilatory threshold and anthropometric characteristics showed that lean body mass was a major determinant of oxygen uptake at the ventilatory threshold during growth.