To compare the effect of weight training (WT) and treadmill (TM) exercise on postexercise oxygen consumption (˙VO2), 15 males (mean ± SD) age = 22.7 ± 1.6 yr; height = 175.0 ± 6.2 cm; mass = 82.0± 14.3 kg) performed a 27-min bout of WT and a 27-min bout of TM exercise at matched rates of ˙VO2. WT consisted of performing two circuits of eight exercises at 60% of each subject's one repetition maximum with a work/rest ratio of 45 s/60 s. Approximately 5 d after WT each subject walked or jogged on the TM at a pace that elicited an average ˙VO2 matched with his mean value during WT. ˙VO2 was measured continuously during exercise and the first 30 min into recovery and at 60 and 90 min into recovery. ˙VO2 during WT (1.58 L·min-1) and TM exercise (1.55 L·min-1) were not significantly(P > 0.05) different; thus the two activities were matched for˙VO2. Total oxygen consumption during the first 30 min of recovery was significantly higher (P < 0.05) as a result of WT (19.0 L) compared with that during TM exercise (12.7 L). However, ˙VO2 values at 60 (0.32 vs 0.29 L·min-1), and 90 min (0.33 vs 0.30 L·min-1) were not significantly different (P > 0.05) between WT and TM exercise, respectively. The results suggest that, during the first 30 min following exercise, WT elicits a greater elevated postexercise ˙VO2 than TM exercise when the two activities are performed at matched ˙VO2 and equal durations. Therefore, total energy expenditure as a consequence of WT will be underestimated if based on exercise ˙VO2 only.