[Intercorrelations and variabilities of heart rate at the rest and during exercise in the evaluation of physical fitness]. / Intercorrélations et variabilité des fréquences cardiaques de repos et d'effort en regard de l'évaluation de l'aptitude physique.

It appears that heart rate measured at rest may significantly affect the values obtained during a sub-maximal effort: isometric as well as isotonic. For this study, 24 male subjects were tested, on a 15 and 30 days interval in a laboratory during an isometric effort. The task was to lift and hold with the arms bent, at a standardized angle of 45 degrees, a 12 kg load during a three minute period. The influence of the resting pulse on the isotonic submaximal values were studied on one subject during a period of 30 days. The authors thus suggest that the battery of tests which determine physical aptitude based on the sole criterion of heart rate as measured during a sub-maximal effort (Astrand's PWC-170, Step test, etc.) take into account the variability of the resting values of this parameter.

[Steady state ergometry: fact or fiction]. / Steady state ergométrique: réalité ou fiction.

The steady state is a physiological condition whereby the metabolic requirements are met and the criteria parameters are stable. Four groups of male subjects were evaluated on their VO2 for a one hour duration ergocycle effort at 75%, 50%, 25% and 10% of their maximum individual VO2. Three cardio-respiratory parameters (heart frequency, oxygen consumption, pulmonary ventilation) and one biochemical parameter (lactic acid) were measured The evolution of the control parameters during the task were completed according to the requirements of the literature. For the long-duration efforts (one hour) we notice the absence of a steady-state for the cardio-respiratory parameter. We cannot however rule-out the existence of a steady state for the biochemical parameter for the lighter efforts of 10% and 25% of the VO2 maximum.

[Review of the literature on myoglobin in the development of exertion and aerobic training]. / Revue de la littérature concernant l'importance de la myoglobine dans le développement de l'effort et de l'entraînement aérobique.

The myoglobin has the property to store the oxygen at the level of the striated muscle. The histological study of the striated muscles proves that the distribution of myoglobin is neither uniform nor identical in all of the muscular fibres (slow twitch and fast twitch fibres). It has been shown that the myoglobin content increases with endurance training but the opposite effect (decrease) has not been formally demonstrated during a training based on short and explosive exercises.