The metabolic and performance effects of carbohydrate timing in resistance trained males undergoing a carbohydrate restricted diet.

Research paper by Ben B Krings, Hunter H Waldman, Brandon D BD Shepherd, Matthew J MJ McAllister, Brent J BJ Fountain, John J Lamberth, JohnEric W JW Smith

Indexed on: 12 Dec '20Published on: 11 Dec '20Published in: Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme


The purpose of this investigation was to examine the importance of carbohydrate (CHO) timing while consuming a carbohydrate restricted diet (CRD) and completing a high-intensity exercise program. Eighteen males completed six weeks of training with the first two weeks serving as familiarization. During the final four weeks, subjects were randomized into two groups and completed three days of resistance training and two days of high-intensity interval training, while consuming a CRD (~25%, ~25%, and ~50%, CHO, protein, and fat, respectively). The supplemented (SUPP) group (n=9) ingested 30 g of CHO during exercise and 40 g of CHO immediately after each training session. The non-supplemented (NONSUPP) group (n=9) consumed a non-caloric placebo during exercise. Pre-and post-testing measures included back squat and bench press one-repetition maximums (1-RM), peak oxygen consumption (V̇O2peak), anaerobic power, body composition, fasted glucose, insulin, and total testosterone. Both groups significantly improved back squat and bench press 1-RM, V̇O2peak, and power output (p<0.05), but there were no differences in blood markers or body composition. Our data suggests that CHO timing does not negatively impact training adaptations during a high-intensity exercise regimen when dietary CHO intake is restricted, but that favorable adaptations can be made while consuming a CRD. Novelty: • Carbohydrate restricted dieting has no negative impact on resistance training adaptations • Short term high intensity interval training is effective in increasing peak oxygen consumption.