Estimated fluid and sodium balance and drink preferences in elite male junior players during an ice hockey game

Abstract

Research in many sports suggests that losing ~2% of body mass (BM) through sweating impairs athletic performance, although this has not been tested in ice hockey players. This study investigated pregame hydration, and on-ice sweat loss, fluid intake, and sodium (Na+) balance of elite male junior players during an ice hockey game. Twenty-four players (2 goalies, 7 defensemen, 15 forwards) volunteered to participate in the study (age, 18.3 ± 0.3 years; weight, 86.5 ±1.6 kg; height, 184.1 ± 1.3 cm). Players were weighed pre- and postgame, fluid and sodium intake were monitored throughout the game, and fluid and Na+ balance were determined within the time between BM measurements. Sweat Na+ loss was calculated based on sweat loss and sweat [Na+] determined from sweat-patch analysis on the same players during an intense practice. Players arrived at the rink in a euhydrated state and drank 0.6 ± 0.1 L of fluid before the game. Mean playing time for the forwards was 18:85 ± 1:15 min:s and playing time for the defense was 24:00 ± 2:46 min:s. Sweat loss was 3.2 ± 0.2 L and exceeded net fluid intake (2.1 ± 0.1 L). Mean BM loss was 1.3% ± 0.3%, with 8/24 players losing between 1.8% to 4.3% BM. Players preferred to drink water and a carbohydrate electrolyte solution before the game and during intermissions, while only water was consumed during each period. Practice mean forehead sweat [Na+] was 74 mmol·L-1. Estimated sweat Na+ losses of 3.1 ± 0.4 g (~8 g NaCl) coupled with low Na+ intake of 0.8 ± 0.2 g (~2 g NaCl) resulted in a significant Na+ deficit by the end of the game. This study demonstrated that despite abundant opportunities to hydrate during a hockey game, one-third of the players did not drink enough fluid to prevent sweat losses of 2% BM or higher. Losing 2% BM has been associated with decreases in athletic performance.

Maintaining hydration with a carbohydrate–electrolyte solution improves performance, thermoregulation, and fatigue during an ice hockey scrimmage

“…We have previously demonstrated that elite ice hockey players lose large amounts of sweat despite practicing in cool ambient temperatures of ϳ11°C (Palmer and Spriet 2008;Palmer et al 2010). Average sweat losses were also high at 3.2 L over a ϳ2.5-h game at ϳ11°C, and many players did not drink enough to prevent BM losses of 1.5% or higher (Logan-Sprenger et al 2011).…”

“…Despite these findings, ice hockey players ingest little CHO (<15 g·h -1 ) either before or during practices and games (Palmer and Spriet 2008;Logan-Sprenger et al 2011) when the ingestion of 30-60 g CHO·h -1 would be the normal recommendation. In addition, many players do not ingest enough fluid to avoid mild dehydration (Logan-Sprenger et al 2011).…”

“…It has been documented that hockey players lose large amounts of sweat during practices and games and dehydrate by ϳ1.5% of their body mass (BM) or greater (Godek et al 2006;Palmer and Spriet 2008;Palmer et al 2010: Logan-Sprenger et al 2011). Research in other stop-and-go sports such as soccer and basketball has demonstrated that mild dehydration of ϳ1.5%-2% BM loss resulted in decreased performance, increased core temperature, and increased fatigue (Maxwell et al 1999;Dougherty et al 2006;Baker et al 2007;Edwards et al 2007).…”

The effect of dehydration on muscle metabolism and time trial performance during prolonged cycling in males

“…Any urine produced was included in the calculation of sweat loss (Logan-Sprenger et al. 2011, 2013b). …”

“…At 45 min, subjects were put on a dry t-shirt and recommenced cycling. Any urine produced was included in the calculation of sweat loss (Logan-Sprenger et al 2011, 2013b.…”