The Effect of a Carbohydrate and Protein Supplement on Resistance Exercise Performance, Hormonal Response, and Muscle Damage

Abstract

Ivy. The effect of a carbohydrate and protein supplement on resistance exercise performance, hormonal response, and muscle damage. J. Strength Cond. Res. 21(2): 321-329. 2007.-The purpose of this study was to determine whether resistance exercise performance and postexercise muscle damage were altered when consuming a carbohydrate and protein beverage (CHO-PRO; 6.2% and 1.5% concentrations). Thirty-four male subjects (age: 21.5 Ϯ 1.7 years; height: 177.3 Ϯ 1.1 cm; weight: 77.2 Ϯ 2.2 kg) completed 3 sets of 8 repetitions at their 8 repetition maximum to volitional fatigue. The exercise order consisted of the high pull, leg curl, standing overhead press, leg extension, lat pull-down, leg press, and bench press. In a double-blind, posttest-only control group design, subjects consumed 355 ml of either CHO-PRO or placebo (electrolyte and artificial sweetener beverage) 30 minutes prior to exercise, 177 ml immediately prior to exercise, 177 ml halfway through the exercise bout, and 355 ml immediately following the exercise bout. There were no significant differences between groups relative to exercise performance. Cortisol was significantly elevated in the placebo group compared to the CHO-PRO group at 24 hours postexercise. Insulin was significantly elevated immediately pre-exercise, after the fourth lift, immediately postexercise, 1 hour, and 6 hours postexercise in CHO-PRO compared to the placebo group. Myoglobin levels in the placebo group approached significance halfway through the exercise bout and at 1 hour postexercise (p ϭ 0.06 and 0.07, respectively) and were significantly elevated at 6 hours postexercise compared to the CHO-PRO group. Creatine kinase levels were significantly elevated in the placebo group at 24 hours postexercise compared to the CHO-PRO group. The CHO-PRO supplement did not improve performance during a resistance exercise bout, but appeared to reduce muscle damage, as evidenced by the responses of both myoglobin and creatine kinase. These results suggest the use of a CHO-PRO supplement during resistance training to reduce muscle damage and soreness.

Carbohydrates plus protein reduces oxidative stress after single bout of aerobic exercise

“…The lack of protection of the CPA or CHO supplementation on muscle damage found in our study corroborates with previous data of the Baty et al (2007) and Cermak et al (2009) who found that supplementation CHO + PRO, before and after the session exercise did not alter muscle damage induced by exercise. Additional information brought by our study is that the addition of antioxidants does not confer protection against muscle damage induced by exercise.…”

Protein Supplementation of a High-Carbohydrate Diet during Resistance Training Enhances Muscle Mass and Function by Increasing Essential Amino Acids

“…The levels of growth hormone, testosterone, cortisol, and insulin increased during and after resistance exercise [45,46]. Growth hormone, testosterone, and insulin have an important role in anabolism, such as the restoration of glycogen and MPS [47,48].…”

“…An increase in exercise intensity especially affects the restoration of damaged tissues by increasing the cortisol level; however, changes in the cortisol level needed for the restoration of damaged muscles vary on the basis of the reaction to body stress [59]. Baty et al [60] reported that carbohydrate intake increases the insulin level and formation of muscle protein by reducing breakdown. The HCHO group showed a higher insulin level and a lower cortisol level than the HPRO group because both the maintenance of blood glucose level with a diet rich in carbohydrates and the anabolic effect of insulin reduced protein breakdown.…”

Dor muscular e atividade de creatina quinase após ações excêntricas: uma análise de cluster

“…Um dos questionamentos em relação a utilização da CK como marcador indireto de dano muscular é pelo fato da molécula de CK possuir grande massa molecular (80 kDa) e, portanto, teria dificuldade em entrar no endotélio microvascular 15 . Desta forma, um pequeno grau de dano muscular que não altere significativamente a permeabilidade da membrana, não faria com que houvesse extravasamento de CK para a corrente sanguínea.…”