Altering the rest interval during high-intensity interval training does not affect muscle or performance adaptations

Abstract

New findings: • What is the central question of this study? Are exercise-induced changes in metabolites and ions a crucial factor in the adaptation of contracting muscle? This was assessed by manipulating the rest period between high-intensity intervals. • What is the main finding and its importance? Our results suggest that the perturbation of muscle metabolites (specifically phophocreatine, lactate and H+) during high-intensity interval training is not a crucial factor regulating related adaptations of the contracting muscle, when training intensity and volume are matched. This has implications for understanding the mechanisms that regulate muscle adaptations. It has been hypothesized that..