| Popis: |
Body composition and submaximal and maximal cardiorespiratory responses during a progressive upright bicycle ergometer test were measured in 410 professional male pilots, aged 20 to 68 years, and divided into four groups (30, 39, 49, and 59 years). Fat-free weight by hydrostatic weighing was not significantly different between groups and fat increased linearly with age, while height was lower and weight levelled off in the oldest group. Aerobic work capacity (VO2max) fell at a rate of 0.25 ml.min-1.kg-1 per year in this unique population of healthy, but generally sedentary men. A subgroup of 10 pilots, tested annually from age 31 to 47, demonstrated a reversal of the age-related decline in VO2max. This was attributable to regular physical activity, short of athletic training, and changes in personal health habits stimulated by self-assessment available from the repeated tests incorporated into the medical prevention program. These data considered in relation to more recent reports of stroke volume during similar maximal exercise protocols suggest that VO2max is limited during aging by a reduction in tissue diffusing capacity or increased maldistribution of perfusion in relation to O2 uptake in muscle and this can be partially prevented by training. Reference standards for heart rate, blood pressure and ventilation during submaximal and maximal exercise levels are presented in relation to energy requirements and work intensity at various ages. |
