Impairment of Thermoregulation and Performance via Mild Dehydration in Ice Hockey Goaltenders

Abstract

During play, ice hockey goaltenders routinely dehydrate through sweating and lose ≥2% body mass, which may impair thermoregulation and performance. Purpose: This randomized, crossover study examined the effects of mild dehydration on goaltender on-ice thermoregulation, heart rate, fatigue, and performance. Methods: Eleven goaltenders played a 70-minute scrimmage followed by a shootout and drills to analyze reaction time and movements. On ice, they either consumed no fluid (NF) and lost 2.4% (0.3%) body mass or maintained body mass with water (WAT) or a carbohydrate–electrolyte solution (CES). Save percentage, rating of perceived exertion, heart rate, and core temperature were recorded throughout, and a postskate questionnaire assessed perceived fatigue. Results: Relative to NF, intake of both fluids decreased heart rate (interaction: P = .03), core temperature (peak NF = 39.0°C [0.1°C], WAT = 38.6°C [0.1°C], and CES = 38.5°C [0.1°C]; P = .005), and rating of perceived exertion in the scrimmage (post hoc: P < .04), as well as increasing save percentage in the final 10 minutes of scrimmage (NF = 75.8% [1.9%], WAT = 81.7% [2.3%], and CES = 81.3% [2.3%], post hoc: P < .04). In drills, movement speed (post hoc: P < .05) and reaction time (post hoc: P < .04) were slower in the NF versus both fluid conditions. Intake of either fluid similarly reduced postskate questionnaire scores (condition: P < .0001). Only CES significantly reduced rating of perceived exertion in drills (post hoc: P < .05) and increased peak movement power versus NF (post hoc: P = .02). Shootout save percentage was similar between conditions (P = .37). Conclusions: Mild dehydration increased physiological strain and fatigue and decreased ice hockey goaltender performance versus maintaining hydration. Also, maintaining hydration with a CES versus WAT may further reduce perceived fatigue and positively affect movements.

Carbohydrate Mouth-Rinsing Improves Overtime Physical Performance in Male Ice Hockey Players During On-Ice Scrimmages

“…Despite greater external loads with CHO MR, internal loads were not different between conditions. The absence of diverging RPE values between CHO and PLA MR with the development of physical fatigue opposes previous CHO-ingestion ice-hockey research (15)(16)(17). However, this observation has been frequently repeated in existing CHO MR exercise research (18)(19)(20).…”

“…Alternatively, Lignell's group examined 3-on-3 full-ice competition, but only during an OT period ( 5 ). The present protocol has previously been used in other hockey research, but for analyzing goaltender performance ( 17 ). Therefore, the current analysis of player external and internal loads across time in small-sided 3-on-3 hockey scrimmage is novel.…”

“…Pre- and post-skate measures were performed off-ice and included urine-specific gravity (USG) and body mass (BM) ( Figure 1 ). USG was measured with a hand-held “pen” refractometer (ATAGO USA Inc., Bellevue, WA, USA), and values <1.020 were accepted as hydrated ( 17 ). BM was measured with participants in minimal clothing.…”

“…In previous research, it was established that the consumption of CHO electrolyte solutions (CES) improved physical performance and helped reduce fatigue across time in ice hockey (15)(16)(17). This was observed as increased voluntary work performed, skating speed and time at high effort, and reduced ratings of perceived exertion (RPE) with CES ingestion.…”

Sex differences in the physiological responses to exercise-induced dehydration: consequences and mechanisms

“…In agreement, when both sexes experienced a similar magnitude of dehydration ($1.2%-1.8% body mass loss greater than control), only females experienced a higher T c ($0.3 C) during intermittent exercise (12-14, 18, 19). Thus, an inability to adequately maintain a thermoneutral T c appears to be initiated at $0.5%-1.0% body mass loss in females (12,16,18), whereas literature concerning male subjects reported that the physiological consequences of exercise-induced mild dehydration were present only beyond >1% body mass loss (20,21). Though limited, these data suggest that thermoregulatory capacity may be impaired at lower relative magnitudes of exercise-induced dehydration in females compared with males, and this hypothesis warrants direct examination in future studies.…”