Constant and Variable-Intensity Distribution High-Intensity Interval Training Approaches: Which Is More Effective in Increasing Time Spent at Maximal Oxygen Uptake? A Narrative Review

Authors : Refik Çabuk, Egemen Alp

Pages : 577-591

Doi:10.17155/omuspd.1770805

View : 149 | Download : 386

Publication Date : 2025-12-21

Article Type : Review Paper

Abstract :The total time spent at high percentages of maximal oxygen uptake (V̇O2max) during a high-intensity interval training (HIIT) session is considered one of the key acute responses for inducing long-term improvements in V̇O2max. Therefore, over the past 15 years, many studies have focused on maximizing the time spent near V̇O2max in constant-intensity HIIT protocols by manipulating variables such as work duration, number of repetitions, recovery duration, and recovery intensity. More recently, however, a limited number of studies have employed strategies that modify the intensity distribution within work bouts in order to increase this time. This narrative review aimed to examine the potential of HIIT strategies with variable intensity distributions to maximize the time spent near V̇O2max compared with constant-intensity HIIT protocols. Accordingly, fast-start, varied-intensity, linearly varying, and stepwise decreasing-intensity protocols were addressed. The findings indicate that, when sufficiently long work bouts are applied to allow V̇O2 to reach maximal levels, variable intensity-distribution HIIT approaches can increase the time spent at V̇O2max compared with traditional constant-intensity protocols. Furthermore, these strategies were found to elicit greater total V̇O2 consumption despite producing similar blood lactate responses and ratings of perceived exertion. These results suggest that HIIT approaches incorporating variable intensity distributions may impose higher aerobic demands.
Keywords : Değişken Şiddetli, Doğrusal Değişen, Hızlı Başlangıç, Maksimal Oksijen Tüketimi, Yüksek Şiddetli İnterval Antrenman

ORIGINAL ARTICLE URL