COMPARISON OF A SIMULATED 16.1-KM TIME TRIAL, VO(2)MAX AND RELATED FACTORS IN CYCLISTS WITH DIFFERENT VENTILATORY THRESHOLDS

Differences in cycling performance have been observed in cyclists with similar VO(2)max values yet different lactate thresholds. The purpose of the current study was to compare a simulated 16.1-km cycling time trial, VO(2)max 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 VO(2)max - Group H) or low (68 +/- 2.8 % - Group L). VO(2)max and a 16.1-km time trial were completed on a Velodyne trainer. No significant difference (p greater than or equal to 0.05) was noted between groups in VO(2)max (Group H 4.00 +/- 0.28 l. min(-1), Group L 4.15 +/- 0.67 l.min(-1)), however significant differences (p less than or equal to 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 +/- 3.03 min. Group H completed the time trial 28% more quickly by working at a significantly higher percentage of VO(2)max, 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 VO2 (l.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 VO(2)max in discerning performance differences in a 16.1-km cycling time trial, and was the best predictor of the simulated time trial performance.