Gender differences in exercise

CPET will be performed in both men and women patients and athletes. The purpose of this chapter is to emphasize more the similarities in the exercise response but also point out some objective differences that result in small differences that should be noted when evaluating the physiologic variables of a test. For the majority of active sports, the results (times and distances) are superior for men. However, there is a spectrum of gender performance differences depending on the sport or event. For instance, the difference in swimming is much less than the long jump in track and field. Some of the effect is attributable to strength alone, as men have higher muscle mass and lower body fat than women. Maximal aerobic capacity is also greater in men, but this difference narrows when VO₂ is corrected for lean body mass, but still persists, most likely secondary to a greater oxygen delivery from higher hemoglobin concentrations found in men. A higher hemoglobin also affects heart rate, which is lower in men for a given VO₂. Lung volumes are 10% lower in women, but gas exchange is similar. Thus, exercise is most likely not affected by this small difference in lung volume. Running efficiency at comparable speeds is slightly lower in women, which may reflect the influence of biomechanical differences. Thus, as one can discern, there is very little which separates men from women during exercise, but the clinician must look for subtle characteristics such as hemoglobin, which is not only lower in healthy women but may reflect excess blood loss and/or iron deficiency.