Nutritional habits prior to exercise can influence metabolic process both during and after an exercise bout. Due to the negative impact of excess body fat on metabolic health, pre-exercise nutrition and exercise interventions that target improved fat oxidation following exercise are warranted. PURPOSE: The purpose of this study was to examine the combined effects of pre-exercise nutrition interventions with high-intensity resistance training (HIRT) on post-exercise metabolic responses in overweight (OW) females. METHODS: Respiratory exchange ratio (RER) was measured in fifteen recreationally active OW females (n = 15, body fat percentage: 31.3 ± 3.9) at baseline (BASE), immediately post (IP) 30-min (30), and 60-min (60) post-HIRT. The following supplements were consumed by participants prior to completing each HIRT bout: carbohydrate (CHO), protein (PRO), caffeine (CAFF, 3 mg/kg body mass), or PRO+CAFF in a randomized, crossover, double-blind design. RER values were assessed via a 4 x 4 repeated measures analysis of variance. RESULTS: Data are presented as means ± SD. RER was not significantly different between any of the nutrition interventions (p > 0.05). However, independent of pre-exercise supplementation, HIRT significantly reduced RER at 30 (0.74 ± 0.05) and 60 (0.74 ± 0.05) post-exercise in comparison to BASE (0.81 ± 0.04; p < 0.001) and IP (0.77 ± 0.06; p < 0.01). CONCLUSION: Collectively, these findings support HIRT as an effective intervention for enhancing fat utilization up to one-hour post-exercise in OW females, independent of pre-exercise nutrition. Given the substantial time demands of traditional resistance training (>60 min), HIRT may offer a more time-efficient strategy for improving fat metabolism.
