Cardiopulmonary Exercise Capacity in Healthy Normals of Different Age

Abstract

Sixty-nine healthy normals from the 3rd to the 6th decade were stressed to exhaustion by means of a cardiopulmonary exercice test on a bicycle ergometer. Peak VO₂, VCO₂ and ventilation differed significantly between the four decades: peak VO₂ (x ± SD) was 3,393 ± 516; 3,061 ± 444; 2,817 ± 801 and 2,589 ± 687 ml/min (p < 0.001). The mean value for respiratory gas exchange ratio (R) at ventilatory threshold (VT) was 0.86 and for ventilatory equivalent O₂ (EqCO₂) 0.24. Mean VO₂at VTwas 1,662 ± 521; 1,462 ± 308; 1,474 ± 559 and 1,268 ± 232 ml/min (p < 0.05). The VO₂ of the four age groups at VT was between 47 and 49% of peak VO₂ (n.s.), and both parameters correlated significantly (r = 0.67, p < 0.001). The average increase of VO₂ in relation to work rate (ml/W/ min) was 11.5 ± 1.2 for the total exercise and was below VT lower (9.4 ± 1.9) than above VT (12.9 ± 1.2) (p < 0.001).