Abstract

The influence of resistance training on human skeletal muscle protein degradation has been estimated by measurement of the urinary excretion of 3-methylhistidine (3-mehis). Sixteen males on a meat-free diet were randomly assigned to control (C) and experimental (E) groups. Pre-training strength tests indicated very little strength difference between the groups. However, by the end of three weeks of daily one hour weight training, the E group had increased its strength index by 18 (p < 0.05). Twenty-four-hour urine samples were collected for all subjects at regular intervals throughout the experimental period. These samples were analysed for total creatinine (Cr) mmol/day, urea (U) mmol/day, and 3-mehis micromol/day. The 3-mehis/Cr ratio, an index of protein degradation, decreased (p < 0.05) from a baseline level of 19.85, SE 1.36 to 14.78, SE 1.37 umol 3-mehis/mmol Cr/day during the training period for the E group; this ratio did not change for the C group over the same time period. The maximum decrease in the degradation index of 25 occurred after only two days of training, and remained significantly smaller than that of the C group up to the final training day. However, the degradation rate increased significantly after training ceased. The results of this study suggest that strength training promotes protein retention by reducing muscular proteolysis. Verf.-Referat