Pedaling Cadence and the V[O.sub.2] Response Profile during Severe Intensity Exercise

The purpose of this study was to determine effects of pedaling cadence on parameters of the V[O.sub.2] response profile in severe intensity cycling. Twelve university students (age, 22 [+ or -] 1 yrs) performed four cycle ergometer exercise tests: (a) one at 256 [+ or -] 39 W using a cadence of 60 rev*[min.sup.-1]; (b) one at the same work rate using 100 rev*[min.sup.-1]; (c) one at 220 [+ or -] 34 W using 100 rev*[min.sup.-1] (the same oxygen demand as the tests at 256 W using 60 rev*[min.sup.-1]); and (d) one at 290 [+ or -] 44 W using 60 rev*[min.sup.-1] (the same oxygen demand as the tests at 256 W using 100 rev*[min.sup.-1]). V[O.sub.2] data were fitted to a two-component model (primary phase + slow component). Analysis revealed an effect of pedaling cadence. At the higher cadence, the primary response was faster (e.g., time constant of the primary phase was smaller, 25 [+ or -] 6 sec versus 32 [+ or -] 6 sec in exercise with a metabolic demand of 108 [+ or -] 3% V[O.sub.2] max) and the slow component emerged sooner. There was also an effect of metabolic demand. The amplitude of the primary phase was greater at the higher oxygen demand (e.g., 2500 [+ or -] 525 mL*[min.sup.-1] versus 2293 [+ or -] 493 mL*[min.sup.-1] in the exercise using 60 rev*[min.sup.-1]) and the amplitude of the slow component was smaller. We concluded that metabolic demand and pedaling cadence exert independent effects on V[O.sub.2] response profiles in severe intensity cycling. Key Words: Cycle Ergometer, Kinetics, Slow Component, V[O.sub.2] max