Individual physiological and mitochondrial responses during 12 weeks of intensified exercise

Abstract

Observed effects of exercise are highly variable between individuals, and subject‐by‐training interaction (i.e., individual response variability) is often not estimated. Here, we measured mitochondrial (citrate synthetase, cytochrome‐c oxidase, succinate dehydrogenase, and mitochondrial copy‐number), performance markers (Wpeak, lactate threshold [LT], and VO2peak), and fiber type proportions/expression (type I, type IIa, and type IIx) in multiple time points during 12‐week of high‐intensity interval training (HIIT) to investigate effects of exercise at the individual level.