Plasma ammonia response to sprint swimming

Background. To study the plasma ammonia response after sprint crawl swimmin g. Methods. Nine sprinters (S) and ten non-sprinters (NS) completed a 15-, a 2 5- and a 50-m crawl at maximal intensity with a 10-min and a 15-min resting period in between. Capillary blood samples were collected before and at re gular intervals after each effort for plasma ammonia determination, Results. Ammonia kinetics differed among distances, but not between groups, with peak values (observed 2-8 min postexercise) being higher after 50 m a s compared to shorter distances, Significant differences between S and NS w ere found in peak ammonia after 50 m (124.5+/-58.2 vs 98.7+/-6.3 mu mol,(-1 )) and in the change of ammonia relative to swim time (Delta NH3/Delta t) a fter 25 m (2.66+/-1.87 rs 1.49+/-0.84 mu mol L-1 s(-1)) and 50 m (1.87+/- 1 .33 vs 1.01+/-0.49 mu mol L-1 s(-1)), Delta NH3/Delta t was highest after 1 5 m (3.33+/-2.53 in S, 3.92+/-1.67 mu mol L-1 s(-1) in NS), Conclusions. These differences in the plasma ammonia response to sprint swi mming according to duration and athlete seem to be connected to distinction s in muscle fiber profile and energy providing processes.