Age-Associated Changes In VO2 and Power Output - A Cross-Sectional Study of Endurance Trained New Zealand Cyclists.

Age-associated changes in power and maximal oxygen consumption (VO2max) were studied in a cross section of endurance trained cyclists. Subjects (n = 56) performed incremental cycling exercise, during which capillary blood lactate [La(-)] was measured. Power output increased by 30 Watts during each 5 minutes stage, with initial power output based on individual ability. When [La(-)] was >4.5 mmol·L(-1), subjects were given a 10 min recovery at a power output approximately 50% below estimated power at [La(-)]4mmol. Subjects then performed an incremental test (1 minute stages) to VO2max. Decline in VO2max was 0.65 ml·kg(-1)·min(-1)·year(-1) (r = -0.72, p < 0.01) for males, and 0.39 ml·kg(-1)·min(-1)·year(-1) (r = -0.54, p < 0.05) for females. Power at VO2max decreased by 0.048 W kg(-1)·year(-1) (r = -0.72, p < 0.01) in males. Power at [La(-)]4mmol decreased by 0.044 W kg(-1)·year(-1) (r = -0.76, p < 0.01) in males, and by 0.019 W kg(-1)·year(-1) (r = -0.53, p < 0.05) in females. Heart rate at VO2max (HRmax) showed a weaker correlation with age in males (r = -0.36, p < 0.05). The age-associated changes in maximum aerobic power and sub-maximal power were gender- specific, thus suggesting different age-related effects on the systems which support exercise in males and females. Key pointsVO2max decreased with age by 0.65 ml·kg(-1)·min(-1)·year(-1) in male, and by 0.39 ml·kg(-1)·min(-1)·year(-1) in female endurance trained cyclists.Power at VO2max decreased with age by 0.048 Watts·kg(-1)·year(-1) in male endurance trained cyclists.Sub-maximal power at a blood lactate concentration of 4mmol·L(-1) decreased by 0.044 Watts·kg(-1)·year(-1) in male, and by 0.019 Watts·kg(-1)·year(-1) in female endurance trained cyclists.