Variabilité de la fréquence cardiaque en fonction de l'intensité de la pratique physique chez la femme ménopausée

Aim. – Study was to asses the heart rate variability related to the physical practice intensity in post menopausal women.Method. – Time domain measurement of heart rate variability has been realised from the electrocardiogram at rest and during exercice in 3 groups of 6 women : untrained, active and trained. At rest, no significant difference betwen groups appears. But, in the standing position, RR interval and the dispersion around RR interval decrease in trained group only. During submaximal exercise, this dispersion is more elevated in active and trained groups.Conclusion. – Physical practice induces a higher response of sinus node to vagal modulation during standing position and submaximal exercise.     

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.     

Estimation de la dépense énergétique lors d'une régate en dériveur

Introduction. – Assess the energetic cost during small craft competition.Methods. – Height healthy sailors have been tested during three regattas. Heart rate, vertical jump, glycemia, cortisol and testosterone have been recorded.Results and discussion. – Regattas did not show significant difference for hormones. However, a significant 10% decrease of glycemia was presented. Heart rate increased during competition, but it was different according to the wind velocity and wind direction. The oxygen cost of sailing is relatively light. However, this cost could be increase with bad conditions of sailing. It seems that aerobic capacity is important regarding performance.