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purpose of this study was to compare the VO2 kinetic and
mechanical power responses of boys and men to all out 90 s sprint
cycle exercise. Eight boys (14.6 ± 0.3 y) and eight men (33.8 ± 6.5
y) volunteered to participate and completed a ramp test (to determine
VO2peak and ventilatory threshold, VT) and then on subsequent
days, two 90 s all out cycle sprints on an isokinetic cycle ergometer.
During each test, breath-by-breath pulmonary gas exchange and power
output were measured. Parameters from the power output profiles were
derived from the average response of the two tests including peak
power (PP, highest power output in 1 s), end power (EP60-90,
power over the last 30 s), and mean power over the 90 s (MP90).
Independent pairwise and dependent t-tests were used to compare the
data from tests between adults and boys subject groups. Significant
differences between adults and boys were found for absolute PP (881.4
± 60.7 vs 533.6 ± 50.7 W), EP60-90 (288.6 ± 25.7 vs 134.3
± 17.6 W) and MP90 (434.5 ± 27.4 vs 238.4 ± 17.3 W, p =0.001)
respectively. Relative to body mass significant differences between
adults and boys were found for EP60-90, MP90
and total work (p < 0.002). The boys attained 90 s VO2
values that were closer to VO2peak than their adult counterparts
(93.3 ± 2.6 vs 84.9 ± 2.3 %, p = 0.03). They also demonstrated faster
VO2 kinetics (10.8 ± 1.5 vs 17.6 ± 1.0 s, p < 0.01).
In conclusion, during all out 90 s cycle sprinting boys were able
to attain VO2 values that were closer to VO2peak
and a faster time constant than adult men. These findings provide
insight into the contribution and speed of response of the aerobic
system during an 'anaerobic' test.
KEY
WORDS: VO2peak, anaerobic, kinetics, aerobic, ergometry.
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