Sprint (N = 9) and non-sprint (N = 10) swimmers completed maximum 15-, 25-, and 50-m crawl swims. Capillary blood samples
were collected before and after each effort to determine plasma ammonia concentrations.
Ammonia kinetics differed between
distances but not between groups.
Sprint tasks seem to be connected to distinctions in muscle fiber profile and energy
delivery processes. This appears to contradict the popular, too-simplistic notion, that sprint efforts up to 45 seconds in most sports use anaerobic mechanisms to their fullest. Each sprint distance, has a unique set of energy demands and fiber use. This is yet another example of the specificity of activities that are commonly thought to be similar or equivalent.
Implication. Muscle fiber use and energy delivery differs between 15-, 25-, and 50-m swims