Table 5 Hydration practices for each included study
From: Pre-cooling for endurance exercise performance in the heat: a systematic review
| Authors, year and reference | Hydration practice |
|---|---|
| Arngrïmsson et al., 2004 [24] | Pre-test: instructed to drink water and other non-caffeinated beverages liberally |
| During the warm-up: water ad libitum. Tap temperature. Amount was recorded and repeated for the second condition. | |
| Not reported/performed during exercise | |
| Booth et al., 1997 [42] | During exercise trial: water ad libitum |
| Cotter et al., 2001 [25] | Pre-test: instructed to drink at least 15 ml/kg BM 2 to 3 h before arrival at laboratory |
| During the warm-up: water ad libitum after warm-up and before exercise trial | |
| Not reported/performed during exercise | |
| Duffield et al., 2010 [41] | Pre-test: 500 ml water 60 min before arrival at the laboratory |
| Not reported/performed during exercise | |
| Gonzalez-Alonso et al., 1999 [40] | Pre-test: 200 to 300 ml with breakfast |
| Not reported/performed during exercise | |
| Hasegawa et al., 2006 [43] | Pre-test: 500 ml 2 h before the trial |
| Immersion: no fluid ingestion | |
| Immersion + water ingestion: water (14 to 16°C) every 5 min during exercise equal to volume sweat loss in sweat test performed at a prior visit to laboratory | |
| Water ingestion: water (14 to 16°C) every 5 min during exercise equal to volume sweat loss in sweat test performed at a prior visit to laboratory | |
| Control: no fluid ingestion | |
| Ihsan et al., 2010 [16] | Pre-test: adequate hydration was strongly encouraged before testing |
| Pre-cooling: 6.8 g/kg BM ice slurry in 150 to 200 g aliquots in intervals of 8 to 10 minutes over a period of 30 minutes (1.4 ± 1.1°C) | |
| Control: 6.8 g/kg BM tap water slurry in 150 to 200 g aliquots in intervals of 8 to 10 minutes over a period of 30 minutes (26.8 ± 1.3°C) | |
| During exercise trial: 100 ml water (26.8 ± 1.3°C) at four intervals | |
| Kay et al., 1999 [28] | During exercise trial: water ad libitum |
| Quod et al., 2008 [27] | Pre-test: 250 ml sport drink diluted to half the manufacturer's recommended strength |
| During exercise trial: 250 ml sport drink diluted to half the manufacturer's recommended strength | |
| Ross et al., 2011 [17] | Pre-test: water (4°C) ad libitum throughout heat stabilization and warm-up |
| Pre-cooling: 14 g/kg BM ice slurry in two 7 g/kg BM boluses 15 minutes apart | |
| Control: water (4°C) ad libitum | |
| During exercise trial: subjects were provided with 350 ml of a 6% carbohydrate-electrolyte drink at 12.5 and 37.5 km to consume ad libitum for the next km (drinks left out in heat temperature to simulate race conditions) | |
| Siegel et al., 2010 [18] | Pre-test: instructed to drink at least 2 l fluid the day before the trial, and 400 ml during the meal consumed before the trial |
| Pre-cooling: 7.5 g/kg BM ice slurry (-1°C) with 5% carbohydrate in 1.25 g/kg BM aliquots every 5 minutes over a period of 30 minutes | |
| Control: 7.5 g/kg BM water (4°C) with 5% carbohydrate in 1.25 g/kg BM aliquots every 5 minutes over a period of 30 minutes | |
| Not reported/performed during exercise | |
| Siegel et al., 2012 [19] | Pre-test: instructed to drink at least 2 l fluid the day before the trial, and 400 ml during the meal consumed before the trial |
| Pre-cooling: 7.5 g/kg BM ice slurry (-1°C) with 5% carbohydrate in 1.25 g/kg BM aliquots every 5 minutes over a period of 30 minutes | |
| Immersion: 7.5 g/kg BM water (37°C) with 5% carbohydrate in 1.25 g/kg BM aliquots every 5 minutes over a period of 30 minutes | |
| Control: 7.5 g/kg BM water (37°C) with 5% carbohydrate in 1.25 g/kg BM aliquots every 5 minutes over a period of 30 minutes | |
| Not reported/performed during exercise | |
| Ückert and Joch, 2007 [26] | Pre-test: avoid fluid for 3 h before start of test |
| Not reported/performed during exercise |