Vätskeförlust, vätskeintag och uppskattad energiförbrukning under träning och match i ett svenskt juniorishockeylag

Sammanfattning

Background: Fluid loss may affect performance in sport. In ice hockey, this is particularly relevant because players perform intermittent high-intensity work while protective equipment may limit heat dissipation. Aim: The aim of this study was to examine whether elite junior ice hockey players replace fluid loss during practice and game play through voluntary fluid intake, and to analyse fluid loss in relation to estimated energy expenditure. Method: The study was conducted as a quantitative field study in which body mass, fluid intake, heart rate data and estimated energy expenditure were collected during one on-ice practice and one game. Nine players were included in the analysis. Body mass was measured before and after activity, and fluid intake was estimated by weighing individual water bottles. Estimated fluid loss was calculated from body mass loss combined with registered fluid intake. Data were analysed using Shapiro–Wilk tests, paired t-tests and Pearson correlation analysis. Results: Estimated fluid loss was significantly higher during the game than during practice (2.74 ± 0.45 L vs. 1.20 ± 0.22 L, p < 0.001). Fluid intake was also higher during the game (1.69 ± 0.20 L) than during practice (0.58 ± 0.12 L, p < 0.001). However, the players did not fully replace their estimated fluid loss during either activity. Fluid replacement corresponded to 48.5 ± 6.6% of estimated fluid loss during practice and 62.3 ± 4.3% during the game. No significant correlation was found between estimated energy expenditure and estimated fluid loss during practice (r = 0.61, R² = 0.37, p = 0.083) or during the game (r = 0.41, R² = 0.17, p = 0.268). Conclusion: Voluntary fluid intake did not fully replace estimated fluid loss during either activity. Total fluid loss, fluid intake and percentage body mass loss were greater during the game. Although the longer measurement period likely contributed to the higher total values, fluid loss also remained higher during the game when expressed per hour, indicating that duration alone did not explain the difference. Fluid loss relative to estimated energy expenditure did not differ between activities, and no significant correlations were found between estimated energy expenditure and fluid loss. The findings should be interpreted as preliminary and context-specific because the study included nine players from one team, one practice session and one game.