Effect Of Hypohydration And Intermittent Running In The Heat On Field Hockey Skill Performance

Abstract

The development of hyperthermia during intermittent running in the heat results in a decline in skill performance. If players begin a match in a state of hypohydration, the thermoregulatory system is stressed further. However, there is limited research into the influence of hypohydration on skill performance during sports that are multifaceted in their demands, such as field hockey. PURPOSE: To determine the influence of moderate hypohydration on field hockey skill performance following simulated field hockey exercise in the heat. METHODS: Seven elite female field hockey players completed two 70-min field hockey-specific intermittent treadmill running trials (FHITP), separated by ∼7 days, in a randomised crossover design. The evening preceding each trial, participants performed a baseline skills tests before dehydrating via passive hyperthermia to elicit 2% dehydration. Subjects then either immediately rehydrated (EUH) or remained dehydrated (DEH). The next morning subjects completed a skills test pre- and post performing the FHITP in the heat (33°C, 60% rh). Hydration status was maintained with ad libitum water intake. Heart rate (HR), rectal temperature (Trec), rating of perceived exertion (RPE) and thirst sensation (TS) were measured during exercise. Total Time (TT), Decision Time (DT) and Penalty Time (PT) were recorded during the skills test. RESULTS: PT was higher post-FHITP in the DEY trial (EUH: 8.4 ± 3.4 vs. DEY: 14.6 ± 6.1 s; P<0.05). TT and DT were slower post-FHITP, with no difference between trials (P=0.02 and P=0.01, respectively). DT was faster in the EUH trial compared to DEH (EUH; 4.06 ± 0.20 vs. DEY: 4.18 ± 0.23 s; P=0.01). There was a significant difference in body mass loss between trials at the start on the FHITP (DEH: 1.8 ± 0.6% vs. EUH: 0.1 ± 0.4%; P<0.05) and at the end of the FHIPT (DEH: 2.1 ± 0.5% vs. EUH: 0.2 ± 0.6%; P<0.05). Trec increased over time (P<0.01) with a concomitant increase in HR in the 2nd half (P<0.01), with no difference between trials. No difference in RPE or TS was evident (P>0.05). CONCLUSIONS: Mild hypohydration may increase decision time and error rate without any detrimental effects to physiological parameters. Furthermore, field hockey specific intermittent running in the heat decreases skill performance, which may be linked to increased thermoregulatory strain.