Influência do jejum e de um protocolo de suplementação com carboidratos e proteínas na força muscular respiratória e periférica : estudo clínico randomizado e cruzado com voluntários saudáveis

Abstract

Introduction: After a few hours of fasting, glycogen is consumed and muscle protein is then metabolized for providing glucose to the tissues. The breaking of the fast with drink enriched with carbohydrates and protein can reduce the catabolic response to fasting, with consequent improvement of muscle function and fatigue. Objective: To evaluate fatigue and strength muscle respiratory and peripheral in healthy adults fasted for 12 full hours or supplementation protocol containing carbohydrates and proteins. Materials and methods: A randomized cross-over clinical trial was conducted, with 15 healthy male volunteers, with normal IMC and age between 20 and 30 years. The volunteers underwent assessment of muscle function tests after either an overnight fast of 12 hours or after period supplementation of carbohydrate and protein (Jucy Drink, Fresenius-Kabi) 2 hours before the tests (200ml). The interval between two tests was 2 to 4 weeks. All individuals underwent the following tests: manovacuometer for measurement of respiratory muscle strength by measuring the maximal respiratory pressures (PImáx e PEmáx), and grip strength of the dominant and non-dominant upper limb to determine the strength and peripheral muscle fatigue. Results: The results of peripheral muscle strength were higher after the supplementation protocol in both the dominant hand and the non-dominant compared to the 12-hour fasting (p<0.004). Muscle fatigue was significantly greater after fasting protocol for the first 4 steps of the sequence (p <0.01). Both inspiratory and expiratory muscle strength showed higher values after nutritional supplementation protocol, though expiratory force was not statistically significant. In general, worsening of muscle function tests was to employees when the volunteers had fasted for 12 hours. Conclusion: After an overnight fasting of healthy subjects, loss of function and overall muscle strength are evident. The supplementation protocol with carbohydrates rich drink proteins improves the muscle strength and the performance of muscle function.