The impact of work-matched interval training on V̇O_2peak and V̇O₂ kinetics: diminishing returns with increasing intensity

Abstract

High-intensity interval training (HIIT) improves peak oxygen uptake (V̇O2peak) and oxygen uptake (V̇O2) kinetics, however, it is unknown whether an optimal intensity of HIIT exists for eliciting improvements in these measures of whole-body oxidative metabolism. The purpose of this study was to (i) investigate the effect of interval intensity on training-induced adaptations in V̇O2peak and V̇O2 kinetics, and (ii) examine the impact of interval intensity on the frequency of nonresponders in V̇O2peak. Thirty-six healthy men and women completed 3 weeks of cycle ergometer HIIT, consisting of intervals targeting 80% (LO), 115% (MID), or 150% (HI) of peak aerobic power. Total work performed per training session was matched across groups. A main effect of training (p < 0.05) and a significant interaction effect was observed for V̇O2peak, with the change in V̇O2peak being greater (p < 0.05) in the MID group than the LO group; however, no differences were observed between the HI group and either the MID or LO groups (ΔV̇O2peak; LO, 2.7 ± 0.7 mL·kg(-1)·min(-1); MID, 5.8 ± 0.7; HI, 4.2 ± 1.0). The greatest proportion of responders was observed in the MID group (LO, 8/12; MID, 12/13; HI, 9/11). A nonsignificant relationship (p = 0.26; r(2) = 0.04) was found between the changes in V̇O2peak and τV̇O2. These results suggest that training at intensities around V̇O2peak may represent a threshold intensity above which further increases in training intensity provide no additional adaptive benefit. The dissociation between changes in V̇O2peak and V̇O2 kinetics also reflects the different underlying mechanisms regulating these adaptations.

Commentary: High-intensity Intermittent Training vs. Moderate-intensity Intermittent Training: Is It a Matter of Intensity or Intermittent Efforts?

“…In this regard, Raleigh et al (2016) investigated the effects of HIIT intensity on training-induced adaptations in VO2peak and VO2 kinetics. The authors compared the effects of HIIT (1 min of effort per 1 min of rest) targeting 80, 115, or 150% of the intensity equivalent to VO2max while matching total work performed.…”

Reproducibility of peak oxygen consumption and the impact of test variability on classification of individual training responses in young recreationally active adults

“…In addition, all of the 16 consistently classified individuals came from Raleigh et al . (), which suggests that correctly classifying individuals may be more difficult with training interventions that do not elicit a large average increase (i.e. large group mean change) in VO 2 peak.…”

“…Participants were asked to refrain from drinking coffee or alcohol 12 and 24 h prior to testing, respectively. For Raleigh et al ., (subjects 1–30), there were no specific guidelines as to the time of day that participants performed the VO 2 peak tests. For Bonafiglia et al ., (subjects 31–45), participants performed all tests within 2 h of each other, except for five participants who had one test that differed from another test by 2·5–4 h, and one participant who had one test that was 7 h different from the others.…”

“…As in the study by Raleigh et al . (), three VO 2 peak tests separated by at least 24 h were performed PRE and POST.…”

An appraisal of the SD IR as an estimate of true individual differences in training responsiveness in parallel‐arm exercise randomized controlled trials

“…In 1999 Bouchard et al () published results from the HERITAGE Family Study demonstrating a wide range of peak oxygen consumption ( V O 2 peak) responses across individuals completing an identical exercise training program. Subsequently, a substantial body of literature has emerged reporting variability in the observed pre–post training changes in V O 2 peak (Hautala et al, ; Vollaard et al, ; Sisson et al, ; Astorino and Schubert, ; Wolpern et al, ; Ross et al, ; Raleigh et al, ; Gurd et al, ; Bonafiglia et al, ; Montero and Lundby, ), peak work rate (Vollaard et al, ; Montero and Lundby, ), lactate threshold (Gurd et al, ; Bonafiglia et al, ), and other physiologically meaningful central (MacPherson et al, ; Astorino et al, ; Raleigh et al, ) and peripheral (Vollaard et al, ; McPhee et al, ; Edgett et al, ; Bonafiglia et al, ; deLannoy et al, ; Raleigh et al, ) adaptations. Importantly, although the existence of variability in the observed response to training cannot be questioned (illustrated in Figure ), it remains unclear whether this variability can be attributed to an effect of exercise per se.…”