Effects of initial performance, gross efficiency and VO_2peak characteristics on subsequent adaptations to endurance training in competitive cyclists

The present study investigated the effects of initial levels of cycling performance, peak oxygen uptake (VO2peak) and gross efficiency (GE) on the subsequent adaptations of these variables and their relationship following high-intensity training designed to increase VO2peak in competitive cyclists. Sixty cyclists (VO2peak = 61±6 mL.kg-1.min-1) were assigned a twelve-week training program consisting of twenty-four supervised high-intensity training sessions and ad-libitum low intensity training. GE was calculated at 125, 175 and 225 W and performance was determined by mean power during a 40-minute time-trial (Power40min). In addition to correlation analyses between initial level and pre- to post-intervention changes of the different variables, we compared these changes between four groups where participants were categorized with either low and/or high initial levels of VO2peak and GE. Average volume of high- and low-intensity training during the 12-week intervention was 1.5 ± 0.3 and 8.3 ± 2.7 and hours.wk-1 respectively. Following the 12-week training period, there was a significant increase in absolute and body mass normalized VO2peak and Power40min (p 0.12). In conclusion, the present findings suggest that there are statistically significant effects of initial levels of cycling performance and VO2peak and on the subsequent adaptations following a 12-week high-intensity training program, but the small and moderate effects indicate limited influence on training practice.