Abstract des Autors

Nine well-trained subjects performed 15-, 30- and 45-s bouts of sprint exercise using a cycle ergometer. There was a significant difference in the mean power between a 15-s sprint (706.0 W, SD 32.5) and a 30-s sprint (627.0 W, SD 27.8; P<0.01). The mean power of the 30-s sprint was higher than that of the 45-s sprint (554.7 W, SD 29.8; P<0.01). Blood ammonia and lactate were measured at rest, immediately after warming-up, and 2.5, 5, 7.5, 10, 12.5 min after each sprint. The peak blood ammonia content was 133.8 micro-mol/l, SD 33.5, for the 15-s sprint, 130.2 micro-mol/l, SD 44.9, for the 30-s sprint, and 120.8 micro-mol/l, SD 24.6, for the 45-s sprint. Peak blood lactates after the 15-, 30- and 45-s sprints were 8.1 mmol/l, SD 1.7, 11.2 mmol/l, SD 2.4, and 14.7 mmol/l, SD 2.1, respectively. There was a significant linear relationship between peak blood ammonia and lactate in the 15-s (r, 0.709; P<0.05), 30-s (r, 0.797; P<0.05) and 45-s (r, 0.696; P<0.05) sprints. Though the peak blood lactate content increased significantly with increasing duration of the sprints (P<0.01), no significant difference was found in peak blood ammonia content among the 15-, 30- and 45-s sprints. These results suggest that the peak value of ammonia in the blood appears in sprints within 15-s and that the blood ammonia level is linked to the lactate in the blood.