Comparison of a Simulated 16.1-km Time Trial, V̇O₂max and Related Factors in Cyclists with Different Ventilatory Thresholds

Abstract

Differences in cycling performance have been observed in cyclists with similar V̇O₂max values yet different lactate thresholds. The purpose of the current study was to compare a simulated 16.1-km cycling time trial, V̇O₂max and related factors in cyclists who significantly varied in ventilatory threshold. From an original group of 18 category III or IV cyclists, two groups of 6 cyclists were formed based on ventilatory threshold values as high (77±4% of V̇O₂max - Group H) or low (68±2.8% - Group L). V̇O₂max and a 16.1-km time trial were completed on a Velodyne trainer. No significant difference (p>0.05) was noted between groups in V̇O₂max (Group H 4.00±0.281·min^-1, Group L 4.15±0.671·min^-1), however significant differences (p < 0.05) were found in ventilatory threshold and time trial scores. Group H completed the time trial in 16.29±2.08 min while Group L averaged 20.93±3.03min. Group H completed the time trial 28% more quickly by working at a significantly higher percentage of V̇O₂max, a higher power output and a faster pedal rate than Group L. From a battery of physiologic and body composition parameters, the ventilatory threshold expressed as V̇O₂ (1·min^-1) was the best predictor (r = -0.76) of time trial performance in the 12 cyclists. The findings of this study indicate that the ventilatory threshold was superior to V̇O₂max in discerning performance differences in a 16.1-km cycling time trial, and was the best predictor of the simulated time trial performance.

Key words

Cycling performance - ventilatory threshold