Thermal regulatory problems associated with playing soccer

Abstract

Playing soccer in a hot environment without drinking fluids is likely to cause dehydration and consequently heat stress related conditions and poor performance. The objective of this study was to determine the amount of total body water loss that soccer players undergo on exposure to various ambient temperatures, ad libitum, before, and after exercise. Sixty-one volunteers, mean age 23 ±3 who play soccer in the Premier Soccer League (PSL) and the First Division Soccer League were recruited into the study. Before the match, they were asked to empty their urinary bladders. They were monitored for changes in body weight and core temperature, albuminuria, urine volume and flow rate, sweat loss, sweating rate and fluid intake. Overall dehydration (total body mass loss) 2.21 ±0.83 %, sweat loss 1.580 ±0.71 litres, sweating rate 0.84 ±0.64 litres/hour, core temperature increase 1.79 ±0.83 %, water intake 0.28 ±0.23 litres, urine output 2.4 x10-2 ±1.5 x10-2 litres, urine flow rate 2.8 x10-4 ±1.6 x10-4 litres/minute and albuminuria 1.2 ±1.4 g/litre. There was a significant correlation between dehydration and water intake (P<0.05) and a strong correlation between dehydration and increase in core temperature and sweat loss (P<0.01). Increase in core temperature had a strong correlation with dehydration, water intake and sweat loss (P<0.01). On predicting dehydration sweat loss, urine output and water intake were significant predictors (P<0.05). On predicting temperature increase, sweat loss was the only predictor (P<0.05). There was a strong positive correlation between the outcome of the game and both the temperature and the extent of dehydration (P<0.01). In conclusion, the results suggest soccer players do not take adequate fluids during the game leading to reduced body mass due to dehydration and consequently poor performance. The increase in the body temperature seemed not to have much bearing on the extent to which dehydration may occur.