Abstract des Autors

Comparison of male and female performance trends in athletics and swimming shows that women tend to improve their results less rapidly than men. Does this divergence reflect unequal physical capacities? Measuring performance implies the determinations of numerous elements. Physical capacities are decisive in explaining performance levels, as expressed by energetic and biochemical factors. The latter are analysed in this study in order to compare performances in both sexes. Energy expenditure may be assessed through the study of maximum aerobic power and aerobic endurance. During tests which required a significant amount of aerobic power, female were observed to be lower than male performances. These differences may be explained by the lower maximal oxygen uptake (VO2 max) in women. Absolute VO2 max values, expressed in l/min are typically 30 to 50 higher in men than in women. Using the relative expression of VO2 max, in ml of oxygen per kg of body weight, the apparent sex difference in maximal aerobic power is reduced to approximately 20. Thus, part of the sex difference in VO2 max is related to the difference in body size and weight. If VO2 max is expressed relative to fat-free weight, the sex difference in VO2 max is further reduced and, in some cases, ceases to exist. A smaller heart size and a lower hemoglobin concentration are two factors which are proposed as a possible hypothesis to explain this variation. The sex differences in VO2 max between trained men and women was less than for untrained subjects. Verf.-Referat