Recovery energy expenditure for steady state exercise in runners and nonexercisers

This study examined the effects of intensity, mode of exercise, and aerobic fitness on the energy expended during recovery (recovery oxygen consumption, or rec VO2) following steady state exercise. Eight runners (4 males, 4 females; 22-32 yr) walked at 3.2 and 6.4 km X h-1 and ran at 8.1 and 11.3 km X h-1 (18, 33, 50, and 68% peak VO2). All subjects completed 3.2 km of walking or running each session. Eight sedentary adults (4 male, 4 female; 21-33 yr) completed the 6.4 km X h-1 test. For the runners, net rec VO2 for 3.2, 6.4, 8.1 and 11.3 km X h-1 exercise was (X +/- SE) 12.52 +/- 3.00, 29.53 +/- 5.41, 28.64 +/- 2.91, and 44.27 +/- 5.32 ml X kg-1, respectively, for the recovery period (18-48 min). Differences among group means were significant (P less than 0.05), except between 6.4 and 8.1 km X h-1 walking (29.53 +/- 5.41 and 35.09 +/- 9.39 ml X kg-1). Statements attributing substantial energy expenditure to the recovery period may be misleading to people exercising at levels similar to those described in this study, since the recovery energy expenditure only amounted to approximately 13-71 kJ (3-17 kcal).