Intensity Matters: Effect of Different Work-Matched Efforts on Subsequent Performance in Cyclists

Abstract

Purpose: To assess the effect of 2 work-matched efforts of different intensities on subsequent performance in well-trained cyclists. Methods: The present study followed a randomized controlled crossover design. Twelve competitive junior cyclists volunteered to participate (age, 17 [1] y; maximum oxygen uptake, 71.0 [4.7] mL·kg−1·min−1). The power–duration relationship was assessed through 2-minute, 5-minute, and 12-minute field tests under fresh conditions (control). On subsequent days and following a randomized order, participants repeated the aforementioned tests after 2 training sessions matched for mechanical work (∼15 kJ/kg) of different intensities (ie, a moderate-intensity continuous-training [60%–70% of critical power; CP] session or a session including high-intensity intervals [3-min repetition bouts at 110%–120% of the CP interspersed by 3-min rest periods]). Results: A significantly lower power output was found in the 2-minute test after the high-intensity training session compared not only with the control condition (−8%, P < .001) but also with the moderate-intensity continuous-training session (−7%, P = .003), with no significant differences between the latter conditions. No significant differences between conditions were found for the remaining tests. As a consequence, the high-intensity training session resulted in significantly lower W′ values compared to both the control condition (−27%, P = .001) and the moderate-intensity continuous-training session (−26%, P = .012), with no differences between the 2 latter conditions and with no differences for CP. Conclusion: A session including high-intensity intermittent efforts induces a greater fatigue, particularly in short-duration efforts and W′, than a work-matched continuous-training session of moderate intensity.