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aim of this study was to examine the effects of different pedalling
cadences on the performance of a subsequent 10km treadmill run. Eight
male triathletes (age 38.9 ± 15.4 years, body mass 72.2 ± 5.2 kg,
and stature 176 ± 6 cm; mean ± SD) completed a maximal cycling test,
one isolated run (10km), and then three randomly ordered cycle-run
sessions (65 minutes cycling + 10km run). During the cycling bout
of the cycle-run sessions, subjects cycled at an intensity corresponding
to 70% Pmax while maintaining one of three cadences, corresponding
to preferred cadence (PC), PC+15% (fast cadence) and PC-15% (slow
cadence). Slow, preferred and fast cadences were 71.8 ± 3.0, 84.5
± 3.6, and 97.3 ± 4.3 rpm, respectively (mean ± SD). Physiological
variables measured during the cycle-run and isolated run sessions
were VO2, VE, RER, HR, RPE, and blood lactate.
Biomechanical variables measured during the cycle-run and isolated
run sessions were running velocity, stride length, stride frequency,
and hip and knee angles at foot-strike and toe-off. Running performance
times were also recorded. A significant effect of prior cycling exercise
was found on 10km running time (p = 0.001) without any cadence effect
(p = 0.801, ω2 = 0.006) (49:58 ± 8:20, 49:09 ± 8:26,
49:28 ± 8:09, and 44:45 ± 6:27 min·s-1 for the slow, preferred,
fast, and isolated run conditions, respectively; mean ± SD). However,
during the first 500 m of the run, running velocity was significantly
higher after cycling at the preferred and fast cadences than after
the slow cadence (p < 0.05). Furthermore, the slow cadence condition
was associated with a significantly lower HR (p = 0.012) and VE
(p = 0.026) during cycling than in the fast cadence condition. The
results confirm the deterioration in running performance completed
after the cycling event compared with the isolated run. However, no
significant effect of cycling cadence on running performance was observed
within the cadence ranges usually used by triathletes.
KEY
WORDS: Bicycling, running, physiology, humans, biomechanics.
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