Effects of on-ice mild dehydration on thermoregulation, performance and mental fatigue in female ice hockey players

This study examined the effect of mild dehydration during a 90 min scrimmage on thermoregulation, performance and mental fatigue in female recreational hockey players. Body mass loss was 1.21 ± 0.08% in the no fluid (NF) trial and maintained in the water (W) and carbohydrate-electrolyte solution (CES) trials. Sweat losses were similar between trials (756-817 mL). Average peak core temperature (Tc) was significantly higher in NF (38.80 ± 0.10°C) vs. W (38.57 ± 0.07°C) and CES (38.46 ± 0.06°C) and also higher in the NF trial in the third period. Subjects reported more negative mood and fatigue profiles in NF and felt less cramping in CES vs. NF, but not in W. On-ice performance and ratings of perceived exertion were unaffected by mild dehydration. In conclusion, sweat rates were low in females during a hockey scrimmage and did not effect on-ice performance, but elevated Tc and measures of mental fatigue.