Abstract

In this study we tested the effects of rapid weight loss on spontaneous muscular activity in boxers (n = 16) and studied nerve conduction measurements in boxers, judokas (n = 15) and weight lifters (n = 6) by a conventional EMG technique (DISA 1500). The reduction in body weight was achieved by active exercise, sauna bathing or diuretic (furosemide) administration. The diuretic group had the highest number of fasciculations after the weight loss. In addition, one boxer in the diuretic group had a tetanic reaction in the electrophysiological test. This phenomenon was not detectable in a follow-up 10 days later, nor 10 months later when the weight loss was achieved by sauna bathing. Acute dehydration had no effect on the conduction velocities of the radial sensory and the median motor nerves, nor did baseline values differ among different sports and untrained controls. Five boxers had, however, decreased (more than -9 m/s) sensory conduction velocity of the radial nerve (both before and after the weight reduction). We found diuretic hypohydration a risky method for rapid weight reduction. By an unknown mechanism it may irritate motor nerves, producing spontaneous muscular activity and twitching. Verf.-Referat