Iowa wrestling study: weight loss and urinary profiles of collegiate wrestlers

A longitudinal study was conducted with various members of the 1975 University of Iowa NCAA championship wrestling team to determine if excessive weight loss, accompanied by signs of dehydration, occurred at the college level of competition. Body weight changes from September to December indicated a mean loss of 6%, while skinfold totals (6 sites) changed from a mean of 58 mm to 37 mm. During a four-month period, mean weight losses of 10.2, 9.5, 8.0, 7.5 and 7.0 lbs occurred in intervals of 12, 4, 3, 2 and 1 day, respectively. Basal urines analyzed throughout the season usually contained 2-3 times the potassium excreted before the season started. Analyses of urines at various intervals during a 2-day time period prior to weigh-in showed a .003 increase in specific gravity, 160 mosm/1 increase in osmolarity, .10 decrease in pH, 45.3 mEq/1 decrease in Na+ concentration, and a 71.3 mEq/1 increase in K+ concentration which suggested that the wrestlers were dehydrated prior to competition. Total urinary electrolyte loss during the 2 days amounted to 3.7% of estimated total body Na+ stores and 3.0% of total body K+ stores. These data were similar to what had been reported for Iowa high school finalists and indicated that collegiate wrestlers were also competing while in a dehydrated state.