Effect of high-intensity interval exercise on lipid oxidation during postexercise recovery.
OBJECTIVE
The aim of this study was to examine whether lipid oxidation predominates during 3 h of postexercise recovery in high-intensity interval exercise as compared with moderate-intensity continuous exercise on a cycle ergometer in fit young men (n = 12; 24.6 +/- 0.6 yr).


METHODS
The energy substrate partitioning was evaluated during and after high-intensity submaximal interval exercise (INT, 1-min intervals at 80% of maximal aerobic power output [Wmax] with an intervening 1 min of active recovery at 40% Wmax) and 60-min moderate-intensity continuous exercise at 45% of maximal oxygen uptake (C45%) as well as a time-matched resting control trial (CON). Exercise bouts were matched for mechanical work output.


RESULTS
During exercise, a significantly greater contribution of CHO and a lower contribution of lipid to energy expenditure were found in INT (512.7 +/- 26.6 and 41.0 +/- 14.0 kcal, respectively) than in C45% (406.3 +/- 21.2 and 170.3 +/- 24.0 kcal, respectively; P < 0.001) despite similar overall energy expenditure in both exercise trials (P = 0.13). During recovery, there were no significant differences between INT and C45% in substrate turnover and oxidation (P > 0.05). On the other hand, the mean contribution of lipids to energy yield was significantly higher after exercise trials (C45% = 61.3 +/- 4.2 kcal; INT = 66.7 +/- 4.7 kcal) than after CON (51.5 +/- 3.4 kcal; P < 0.05).


CONCLUSIONS
These findings show that lipid oxidation during postexercise recovery was increased by a similar amount on two isoenergetic exercise bouts of different forms and intensities compared with the time-matched no-exercise control trial.
Malatesta
Davide
D
Institute of Sport Sciences and Physical Education (ISSEP), University of Lausanne, Lausanne, Switzerland. davide.malatesta@unil.ch
Werlen
Catherine
C
Bulfaro
Stefano
S
Chenevière
Xavier
X
Borrani
Fabio
F
D000328:Adult; D050260:Carbohydrate Metabolism; D015331:Cohort Studies; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D050356:Lipid Metabolism / Q000502:physiology*; D008297:Male; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D055815:Young Adult