Effects of Initial Performance, Gross Efficiency and O2peak Characteristics on Subsequent Adaptations to Endurance Training in Competitive Cyclists

Abstract

The present study investigated the effects of initial levels of cycling performance, peak oxygen uptake (O2peak) and gross efficiency (GE) on the subsequent adaptations of these variables and their relationship following high-intensity training (HIT) designed to increase O2peak in competitive cyclists. Sixty cyclists (O2peak = 61 ± 6 mL kg-1 min-1) were assigned a 12-week training program consisting of twenty-four supervised high-intensity interval 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-min time-trial (Power40 min). 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 O2peak 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 h·week-1, respectively. Following the 12-week training period, there was a significant increase in absolute and body mass normalized O2peak and Power40 min (p < 0.05) and a significant decrease in GE (p < 0.05) for all athletes pooled. There was no change in body mass following the 12-week training period. We found a moderate negative correlation between initial level of O2peak and the change in O2peak following the training period (r = -0.32; p < 0.05). A small negative correlation was also found between initial Power40 min and its change following training both when expressed in absolute power and power normalized for body mass (r = -0.27 and -0.28; both p < 0.05). A moderate negative correlation was also found between initial levels for GE and its change following training (r = -0.44; p < 0.01). There were no differences between the four groups based on initial levels of O2peak and GE in the response to training on O2peak, GE, or Power40 min (all p > 0.12). In conclusion, the present findings suggest that there are statistically significant effects of initial levels of cycling performance and O2peak and on the subsequent adaptations following a 12-week HIT program, but the small and moderate effects indicate limited influence on training practice.

Improving Utilization of Maximal Oxygen Uptake and Work Economy in Recreational Cross-Country Skiers With High-Intensity Double-Poling Intervals

“…This combination is in contrast to previous studies showing slightly reduced work economy or gross efficiency when boosting VO 2max over a short period, like e.g. Skovereng et al 26 and Vandbakk et al 25 . Skovereng et al found a moderate correlation between improved VO 2max and deteriorated gross efficiency in cycling, which may indicate a deteriorated work economy although care should be taken when comparing oxygen cost results vs. gross efficiency results.…”

“…a much shorter interval duration and a much higher intensity than in the present study. On the other hand, the mean intensity for 4 • 4 minutes protocol in Skovereng et al 26 was 89% HR max . This is in line with the durations and intensities of the present study, which was 90-95% of HR peak in DP, and thus approximately 88-93% of HR max .…”

Physiological adaptation of aerobic efficiency: when less is more

“…We and others have previously shown that efficiency can change and that acute decreases in efficiency can allow a higher power output under certain conditions (5,7). This trade-off could also explain why there are no differences in efficiency between competitive cyclists and noncyclists (5) and the seemingly controversial findings that efficiency has been found to both increase (3) and decrease (8) after training.…”

Changes in Triathletes’ Performance and Body Composition During a Specific Training Period for a Half-Ironman Race

“…As these results show, the initial level of performance significantly conditions the adaptations generated by training. Recent research (Skovereng et al, 2018) has also shown that there are statistically significant differences between the initial level of performance and VO2peak and subsequent adaptations following a 12-week high intensity interval training program in trained cyclists. Yet, these authors note that the small and moderate effects indicate a limited influence on training practice.…”