Variations du cortisol salivaire au cours de 15 semaines d’entraînement mixte aérobie et anaérobie chez des lutteurs juniors de haut niveau : corrélations avec les performances

Introduction

The goal of this study was to verify if cortisol could be used as an indicator of work load during a mixed aerobic and anaerobic training.

Results

Throughout a 15-week training period in 12 young wrestlers, salivary cortisol was assayed every three weeks and the explosive stength was evaluated on weeks 4 and 15. The results show that the wrestlers who have the highest mean levels of cortisol are those which progress less in explosive force (r = −0.72, P < 0.01).

Conclusion

It seems that the follow-up of cortisol should be an indicator of the load of training.     

Évolution des coordinations musculaires au cours du pédalage chez le sujet âgé régulièrement entraîné en endurance

AimMuscular activity of elderly people regularly trained in endurance was recorded and compared to young adults to study the age-related effect on muscular coordination during cycling.MethodSixteen elderly people (seniors: 66,1 ± 5,8 years) and 10 young adults (juniors: 25,4 ± 4,6 years) with the same endurance training level, performed a 10 min cycling exercise at high power output. Before exercise, voluntary maximal isometric force (FMV) of knee extensors was assessed and compared between the two groups. During cycling, electromyographic activity of the main muscles involved in cycling was recorded with surface electrodes.Results and discussionResults indicate lower values of FMV for seniors than for juniors. During the cycling exercise, seniors are characterized by a lower agonistic muscle's activity and a higher antagonistic activity, when compared with juniors.ConclusionOur study confirms the decrease of force with ageing, even for elderly people regularly trained in endurance. Moreover the two groups of people seem to develop different muscular activation strategies. Endurance training with ageing could thus result in particular muscular activity in cycling.     

Evaluation échographique des effets cardiaques de la course à pied chez le marathonien et le sédentaire avant et après entraînement

Left ventricular (LV) morphology and function were studied by echocardiography at rest in 25 Marathon (M) runners and 11 sedentary young adults before and after two years of periodic endurance training.The following echocardiographic TM computerized measurements were performed: LV diameters (D) thickness (Th) mass, and the maximum rates of posterior wall thickness (PWTh) changes in systole (SdTh/dt/Th) and diastole (DdTh/dt/Th).When compared to 20 normal adults (Nls) Marathon runners exhibited significant increase in LV end-diastolic diameters, thickness and mass (156 ± 38 vs 111 ± 29 g/m², P<0.001). This myocardial hypertrophy was associated with a decrease in LV contractility (StdTh/dt/Th M 3.2±0.7 vs Nls 4.8±1.2 P<0.001) and relaxation (DdTh/dt/Th M 4.6±1.2 vs Nls 7±1.6 S⁻¹ P<0.001). The ratio of end diastolic LV D/2 by PWTh was significantly lower in M (2.66±0.58) than in Nls (3.25±0.72 P<0.01). These results suggest that in M LV hypertrophy is ‘inappropriate’ at rest but perfectly adapted to effort, because long distance runners have the unique alibity to increase their diastolic LV dimensions during exercise.On the opposite, two years of periodic training, allowing 11 sedentary men to run 20 km at 10 km/hour speed, greatly increased their physical condition assessed by stress test but produced no changes in echocardiographic parameters under basal conditions.This longitudinal prospective echocardiographic study demonstrates that long term intensive prolonged running program is required to modify ventricular muscle when studied at rest.