Abstract des Autors

Fifty male runners aged between 30 to 80 years were examined to determine the relative roles of various cardiovascular parameters which may account for the decrease in maximal oxygen uptake (V02max) with aging. All subjects had similar body fat composition and trained for a similar mileage each week. The parameters tested were V02max, maximal heart rate (HRmax), cardiac output (Q), and arteriovenous difference in oxygen concentration (Ca-Cv)02 during graded, maximal treadmill running. Average body fat and training mileage were roughly 12 and 50 km/week, respectively. The average 10-km runtime slowed significantly by 6.0/decade (10-km run-time (min) = 0.323 X age (years) + 24.4). A strong correlation was found between age and V02max (V02max (ml/kg/min) =- 0.439 X age + 76.5). Thus V02max decreased by 6.9/decade along with reductions of HRmax (3.2/decade) and Q (5.8/decade) while no significant change with age was observed in estimated (Ca-Cv)02. It was concluded that the decline of V02max with aging in runners was mainly explained by the central factors (represented by the decline of HR and Q in this study), rather than by the peripheral factor (represented by (Ca-Cv)02).