Seven non-obese adult females (40 ± 8 years) were studied in a room calorimeter on a day that resistance exercise (REX) was performed (4 sets of 10 exercises) and on a nonexercise control day (CON). Twenty-four-hour energy expenditure (EE) on the REX day (mean ± SD, 2,328 ± 327 kcal·d-1) was greater than CON (2,001 ± 369 kcal·d-1, p < 0.001). The net increase in EE during and immediately after (30 minutes) exercise represented 76 ± 12% of the total increase in 24-hour EE. Twenty four-hour RQ on the REX day (0.86 ± 0.06) did not differ from CON (0.87 ± 0.02). Twenty four-hour carbohydrate oxidation was elevated on the REX day, but 24-hour fat and protein oxidation were not different. Thus, in women, the increase in EE due to resistance exercise is largely seen during and immediately after the exercise. The increased energy demand is met by increased carbohydrate oxidation, with no increase in 24-hour fat oxidation. © 2005 National Strength & Conditioning Association.