Carbohydrate restriction: Friend or foe of resistance-based exercise performance?

Highlights

 

The metabolic glycolytic response to resistance exercise is diverse and likely most attributable to volume, duration, and intensity of effort.

Low muscle glycogen may not impair all resistance exercise performance, but increasing blood glucose before exercise may enhance higher-volume, longer-duration performance.

Carbohydrate-restricted hypocaloric diets are effective for reducing fat mass during resistance exercise, but carbohydrate-sufficient hypercaloric diets are likely optimal for inducing muscle hypertrophy.

 

Abstract

It is commonly accepted that adequate carbohydrate availability is necessary for optimal endurance performance. However, for strength- and physique-based athletes, sports nutrition research and recommendations have focused on protein ingestion, with far less attention given to carbohydrates. Varying resistance exercise protocols, such as differences in intensity, volume, and intraset rest prescriptions between strength-training and physique-training goals elicit different metabolic responses, which may necessitate different carbohydrate needs. The results of several acute and chronic training studies suggest that although severe carbohydrate restriction may not impair strength adaptations during a resistance training program, consuming an adequate amount of carbohydrate in the days leading up to testing may enhance maximal strength and strength–endurance performance. Although several molecular studies demonstrate no additive increases in postexercise mammalian target of rapamycin 1 phosphorylation with carbohydrate and protein compared with protein ingestion alone, the effects of chronic resistance training with carbohydrate restriction on muscle hypertrophy are conflicting and require further research to determine a minimal carbohydrate threshold necessary to optimize muscle hypertrophy. This review summarizes the current knowledge regarding carbohydrate availability and resistance training outcomes and poses new research questions that will better help guide carbohydrate recommendations for strength and physique athletes. In addition, given that success in physique sports is based on subjective appearance, and not objective physical performance, we also review the effects of subchronic carbohydrate ingestion during contest preparation on aesthetic appearance. 

Keywords

Muscle hypertrophy
Protein metabolism
Bodybuilding
Bbody composition
Glycogen
Muscular strength
Muscular endurance

Autor / Fonte:Jason M Cholewa, Daniel E Newmire, Nelo Eidy Zanchi Nutrition 2018 October 6, 60: 136-146
Link: https://www.sciencedirect.com/science/article/pii/S0899900718309535