The purpose of the current study was to examine the effect of aerobic endurance exercise (AEE), high-intensity interval training (HIIT), and high-intensity resistance training (HIRT), combined with pre-exercise carbohydrate (CHO) or protein (PRO) ingestion on resting energy expenditure (REE) and respiratory exchange ratio (RER) in women. Participants completed six sessions, of three exercise modalities: AEE, HIIT, and HIRT, and two acute nutritional interventions: 25 grams of CHO and PRO. Measurements were taken at baseline, immediately post, 30min post and 60 min post. Post exercise, HIIT elicited the largest increase in REE compared to AEE (p