Effects of interval and continuous training on O2 uptake kinetics during severe-intensity exercise initiated from an elevated metabolic baseline.

Journal of applied physiology (Bethesda, Md. : 1985)

PubMedID: 24526579

Da Boit M, Bailey SJ, Callow S, DiMenna FJ, Jones AM. Effects of interval and continuous training on O2 uptake kinetics during severe-intensity exercise initiated from an elevated metabolic baseline. J Appl Physiol. 2014;.
The purpose of this study was to test the hypothesis that VO2 kinetics would be speeded to a greater extent following repeated sprint training (RST), compared to continuous endurance training (ET), in the transition from moderate- to severe-intensity exercise. Twenty-three recreationally-active subjects were randomly assigned to complete six sessions of ET (60-110 min of moderate-intensity cycling) or RST (four to seven 30-s all-out Wingate tests) over a two-week period. Subjects completed three identical 'work-to-work' cycling exercise tests before and after the intervention period, consisting of baseline cycling at 20 W followed by sequential step increments to moderate- and severe-intensity work rates. The severe-intensity bout was continued to exhaustion on one occasion and followed by a 60-s all-out sprint on another occasion. Phase II pulmonary VO2 kinetics was speeded by a similar magnitude in both the lower (ET Pre: 28 ± 4, ET Post: 22 ± 4 s; RST Pre: 25 ± 8, RST Post: 20 ± 7 s) and upper (ET Pre: 50 ± 10, ET Post: 39 ± 11 s; RST Pre: 54 ± 7, RST Post: 40 ± 11 s) steps of the work-to-work test following ET and RST (P<0.05). The tolerable duration of exercise and the total amount of sprint work completed in the exercise performance test were also similarly enhanced by ET and RST (P<0.05). Therefore, ET and RST provoked comparable improvements in VO2 kinetics and exercise performance in the transition from an elevated baseline work rate, with RST being a more time-efficient approach to elicit these adaptations.