There were no differences between diets in muscle glycogen storage over 24 h between equi-Caloric diets of carbohydrate alone (approx 10 grams of CHOper kg body wt per 24 hours and a mixed diet of CHO/Pro/fat.
In recent years, post-exercise nutrition has evolved as an imperative part of training regimens among athletic populations. Athletes of all ages, abilities, and skill levels are adopting some form of post-exercise nutrition to improve performance and enhance the body’s recovery processes following exercise. Athletes in particular are highly susceptible to the detriments of heavy training regimens, because they are constantly depleting their energy substrates and stressing skeletal muscle tissues simultaneously. The macronutrients that have drawn much attention, in reference to the recovery phase of exercise, are protein and carbohydrates. Protein and carbohydrates have their own distinct functions, yet both work to generate an anabolic state within the body when ingested after the completion of an exercise bout. It is necessary for individuals who seek to gain lean muscle mass to induce a positive protein turnover as often as possible. It has been confirmed that protein and/or amino acid ingestion is required to reach a positive protein/nitrogen balance (Borsheim et al., ; Koopman et al., ; Tipton et al., ), and carbohydrate ingestion alone provides marginal benefits on protein synthesis rates (Roy, ). Carbohydrate intake during recovery has been shown to replenish depleted glycogen after intense or exhaustive exercise (Ivy et al., ; Ivy et al., ; Reed et al., ). The addition of protein can further enhance this process (Ivy, et al., ), but only in situations when an inadequate amount of carbohydrate is made available in the diet (van Loon et al., ). A lack of glycogen stores in the muscle and liver will limit the performance capacities of the body during prolonged or higher intensity bouts of exercise (Coyle et al., ). The provided evidence clearly denotes the importance these two macronutrients have in regards to post-exercise nutrition and anabolism. Therefore, the purpose of this review is to discuss the impact of dietary protein and carbohydrate intake during the recovery state on muscle protein synthesis and glycogen synthesis.
Glycogen branching enzyme
N2 - The enzymes Akt, mTOR, p70S6K, rpS6, GSK3, and glycogen synthase interact in the control of protein and/or glycogen synthesis in skeletal muscle, and each has been found to respond to exercise and nutrient supplementation. In the present study, we tested the hypothesis that nutrient supplementation post exercise, in the form of a carbohydrate-protein (CHO-PRO) supplement, would alter the phosphorylation state of these enzymes in a manner that should increase muscle protein and glycogen synthesis above that produced by exercise alone. After a 45 min cycling session followed by sprints and again 15 min later, the subjects (n = 8) ingested 400 ml of a CHO-PRO drink (7.8% dextrose and 1.8% protein-electrolyte) or a placebo drink, as assigned using a randomized, counter-balanced design with repeated measures. Biopsies of the vastus lateralis were taken before exercise and at 45 min of recovery. At 45 min after supplementation, CHO-PRO treatment yielded greater phosphorylation of Akt (65%), mTOR (86%), rpS6 (85-fold), and GSK3α/β (57%) than pre-exercise levels (p