Effect of a 15% increase in preferred pedal rate on time to exhaustion during heavy exercise.
The aim of this study was to evaluate the effect of a 15% increase in preferred pedal rate (PPR) on both time to exhaustion and pulmonary O(2) uptake (VO(2)) response during heavy exercise. Seven competitive cyclists underwent two constant-power tests (CPT) at a power output that theoretically requires 50% of the difference in VO(2) between the second ventilatory threshold and VO(2)max (Pdelta50). Each cyclist cycled a CPT at PPR (CPTPPR) and a CPT at +15% of PPR (CPT+15%) in a randomized order. The average PPR value was 94 +/- 4 rpm, and time to exhaustion was significantly longer in CPTPPR compared with CPT+15% (465 +/- 139 vs. 303+/- 42 s, respectively; p = 0.01). A significant decrease in VO(2) values in the first minutes of exercise and a significant increase in VO(2) slow component was reported in CPT+15% compared with CPT(PPR). These data indicate that the increase of 15% PPR was associated with a decrease in exercise tolerance and a specific VO(2) response, presumably due to an increase of negative muscular work, internal work, and an altering of motor unit recruitment patterns.
Nesi
Xavier
X
Faculté des Sciences du Sport et de l'Education Physique, Université de Lille, France.
Bosquet
Laurent
L
Berthoin
Serge
S
Dekerle
Jeanne
J
Pelayo
Patrick
P
D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D001642:Bicycling / Q000502:physiology*; D015444:Exercise; D005080:Exercise Test; D017079:Exercise Tolerance; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance; D005082:Physical Exertion; D015656:Respiratory Mechanics; D013997:Time Factors