Iowa wrestling study: changes in the urinary profiles of wrestlers prior to and after competition.

During the 1973 and 1974 state high school wrestling championships, urine samples were obtained from wrestlers prior to the weigh-in, immediately before they wrestled, and immediately after the subjects had completed their match. Specific gravity, osmolarity, pH, sodium and potassium determinations, as well as qualitative tests for protein and ketones, indicated that the wrestlers were in a dehydrated state at the time of weigh-in. After the five hour interim between the weigh-in and the first match, all but the pH measure remained essentially unchanged. This absence of significant changes in the urinary profile suggests that the wrestlers were unable to rehydrate during the five hour time period between the weigh-in and the first match and that they were competing in a dehydrated state. Urine samples collected after competition were significantly lower in specific gravity, osmolarity and potassium concentration than samples obtained before the match. The urinary potassium levels were of interest because at the three conditions (weigh-in, before the first match, after competition) they were 73-182% higher than values reported for high school students who were nonwrestlers.