| 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
WORDS: Maximal
oxygen consumption, aging, exercise, performance.
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