Taux sériques du propeptide aminoterminal du procollagène III chez des sportifs soumis à un entraînement régulier

Serum Procollagen III N-terminal Propeptide (PIIINP), a marker of bone matrix turnover, was measured in 36 sportsmen undergoing intensive training, including 23 adolescent gymnasts. All values are within the range of control values for age, suggesting that PIIINP is not modified by intensive training.     

Étude comparative de l'analyse spectrale de la fréquence cardiaque au cours de l'exercice sur ergocycle et de l'entraînement en judoHeart rate comparative study by spectral analysis between two exercises: ergocycle vs judo randori

Aim – Heart rate comparative study by spectral analysis between a 6 minutes judo randori et a 4 minutes ergocycle exercise at .Materials and methods – By ten male judokas, both time series were analyzed by short term Fourier transform (time/frequency analysis). Each 512 RR time series drawn from ECG was subdivided by Hanning windowing in 13 samples of 128 values (32 RR periods step). For each sample, both exercise types, means of the ten spectrograms have been computed, yielding two mean spectrograms for each sample.Results – 1) Despite a near maximal heart rate (HR) level between the two exercise types, the spectral energy computed from judo randori was significantly more important than ergocycle spectral energy. This phenomenon yields a qualitative effect of the exercise type (judo or ergocycle) on HRV. 2) the normalized spectral powers of low frequency and high frequency bands respectively, were not significantly different between both exercise types.Conclusion – The autonomie nervous control on HR would depend rather on exercise load than on exercise type.     

Effets en miroir de l''entraînement et du surentraînement sur la fonction somatotrope et la balance glucidolipidique à l''exerciceEffects out of mirror of the drive and overtraining on the somatotropic function and the glucido-lipidic balance with the exercise

Objective. – To confirm the assumption whereby overtraining would have opposite effects on the utilisation of the substrates and the somatotropic function.Exposed facts. – The drive has different effects according to its characteristics and its level. It seems y to have two types of drive: that which amplify the aptitude to oxidize lipids (low powers) and that which accroit the aptitude to oxidize glucides (high powers and/or intermittent exercise). Overtraining reverses these two effects. The somatotropic axis has an evolution parallel with these processes and seems implied in those.Conclusion. – This diagram deserves to be confirmed by additional studies.     

Le « syndrome des jambes lourdes » chez les athlètes surentraînés est-il le reflet de désordres hémorhéologiques ?Is the feeling of heavy legs in overtrained athletes related to impaired hemorheology?

Introduction. – The aim of this work is to evaluate if the feeling of heavy legs in athletes is correlated with overtraining syndrome-related hemorheological disturbances.Results. – The subjects who quoted the item: “I have the feeling of heavy legs” had higher plasma viscosity and higher red cell aggregation parameters. The overtraining score was correlated positively with plasma viscosity, and aggregability parameters. The feeling of heavy legs was correlated with plasma viscosity and aggregability.Conclusion. – These findings suggest that the feeling of heavy legs in overtrained athletes is related to overtraining syndrome-related hemorheologic disturbances, namely mild plasma hyperviscosity and mild erythrocyte hyperaggregability.     

Modification de la lipolyse du tissu adipeux après un entraînement en endurance chez des sujets obèses

This study investigates the effect of a 3 month endurance training on in vitro adipose tissue lipolysis in 13 obese men (body mass index: 36.9 ± 1.3 kg/m²). Training decreased body fat mass percentage (P < 0.05), without body weight change. Lipolytic effects of epinephrine, isoproterenol (β-adrenoceptor agonist) and dobutamine (β₁-adrenoceptor agonist) were significantly increased (P< 0.05). Antilipolytic effects of α₂-adrenoceptor and insulin were significantly decreased (P < 0.05). Endurance training in obese men enhances adipose tissue lipolysis through β-adrenergic pathway, and decreases antilipolytic activity.     

Composante lente de VO2 chez l''enfant prépubère lors d''exercices rectangulaires d''intensité élevéeThe slow component of VO2 uptake kinetics during high-intensity exercise in prepubertal children

Aim – The aim of the present study was to investigate the VO2 uptake slow component in prepubertal children of different aerobic capacity during high intensity exercise.Method – Twenty three (12 well-trained and 11 untrained) prepubertal children took part in two constant-power tests performed at intensities corresponding to 80% of the anaerobic threshold and 90% of maximal aerobic power. VO2 kinetics during both constant-power tests was determine using a monoexponential + linear term model.Results/conclusion – Our results demonstrated the existence of a slow component during heavy intensity exercise in prepubertal children, as previously described in adults. The magnitude of this slow component did not differ between trained swimmers and untrained children exercising at the same relative intensity, provided that the whole VO2 response was considered.