The purpose of this study was to compare recovery energy expenditure following three exercise conditions varying widely in intensity and duration. Subjects were five well-trained female distance runners whose mean age and VO2 max +/- 1 SD were 22.4 +/- 1.6 yr and 61.8 +/- 7.3 ml/kg-1/min-1, respectively. Exercise sessions consisted of walking for 2 h at 24.5% of VO2max, running continuously for 10 min at 81.1% of VO2max, and exercising intermittently with 2 min runs at 89.2% VO2max alternated with 2 min walks at 93.8 m/min-1. VO2 was determined continuously with open circuit spirometry during 1 h of exercise recovery. Total recovery VO2 (L) was taken as the sum of the 60 1-minute values. After walking, VO2 reached baseline values at 40 min of recovery while VO2 remained elevated at 1 h for both the continuous and intermittent exercise. The total VO2 (L) in recovery was significantly greater (p < 0.05) for both continuous (19.09 +/- 1.2 VO2) and intermittent (22.4 +/- 1.5 L) running than walking (17.4 +/- 0.7 L) and intermittent exercise recovery VO2 was significantly greater than for continuous running (p < 0.05). It was concluded that high intensity exercise, either intermittent or continuous, increases recovery VO2 (L) more than prolonged low intensity exercise. Furthermore, the total exercise VO2 explains a large portion of the variance in recovery VO2.