Table 1.
Characteristics of research studies evaluating athletic performance on continuous exercise tasks (studies are presented by order of effect)
| Citation | Participants | VO2 max | Dh protocol (exercise intensity); ambient temperature; duration | Total REC (min) | Dh trial BM loss (%) | Fluid type | Fluid assimilation time (min) | Fluid intake (L kg BM lost−1) | Duration (min) | Performance indicator | Ambient temperature; RH; airflow | Hedges’ g |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Kenefick et al. (2010a) [41] | 8 M | 43.6 ± 4.1 | EX; 50 °C; 3-h W/R | 120 | 4.1 | NaCl | 300 | 1.05 | 15 | TW (cycle ergometer) | 10 °C | 0.05 |
| Chevront et al. (2005a) [42] | 8 (6 M), physically active | 48 ± 9 | HT | 210 | 3.0 | NS | 390 | 1.00 | 30 | TW (cycle ergometer) | 2 °C; 50%; 2.2 m/s | 0.11 |
| Stewart et al. (2014) [37] | 7 M, recreational cyclists | 52.7 ± 7.9 | EX (H); 37 °C; 120 min | 120 | 3.8 | Water | 120 | 1.15 | 7.2 | TT (cycle ergometer) | 18–25 °C; 20–30% | 0.12 |
| McConell et al. (1999a) [25] | 8 M, well-trained cyclists/triathletes | 63.8 ± 1.2 | EX (V); 21 °C; 45 min | 0 | 1.9 | Water | 45 | 1.00 | 15 | TW (cycle ergometer) | 21 °C; 41%; airflow NS | 0.15 |
| McConell et al. (1999b) [25] | 8 M, well-trained cyclists/triathletes | 63.8 ± 1.2 | EX (V); 21 °C; 45 min | 0 | 1.9 | Water | 45 | 0.50 | 15 | TW (cycle ergometer) | 21 °C; 41%; airflow NS | 0.24 |
| McConell et al. (1997a) [24] | 7 M, well-trained cyclists/triathletes | 68. ± 2.5 | EX (V); 21 °C, 120 min | 0 | 3.2 | Deionized water | 120 | 0.50 | 3.5 | TTE (cycle ergometer) | 21 °C, 43%; airflow NS | 0.24 |
| Kenefick et al. (2006) [36] | 8 M, unacclimated | 63.7 ± 10.2 | EX (M); 36 °C; 75 min | 30 | 2.3 | NaCl + NNS | 20 | 1.00 | 55 | TTE (treadmill running) | 37 °C; 42% | 0.28* |
| Hillman et al. (2011a) [29] | 7 M, unacclimated, competitive cyclists | NS | EX (V); 34 °C; 90 min | 15 | 3.0 | Water | 105 | 1.00 | 7.2 | PO (cycle ergometer) | 23 °C | 0.32 |
| Chevront et al. (2005b) [42] | 8 (6 M) physically active | 48 ± 9 | HT | 210 | 2.9 | NS | 390 | 1.00 | 30 | TW (cycle ergometer) | 20 °C; 50%; 1 m/s | 0.35* |
| Paik et al. (2009) [50] | 10 M, moderately active | 53.6 ± 11.4 | HT | 120 | 3.0 | Water | 120 | 1.00 | 30 | TTE (treadmill running) | NS | 0.43 |
| McConell et al. (1997b) [24] | 7 M, well-trained cyclists/triathletes | 68.4 ± 2.5 | EX (V); 21 °C, 120 min | 0 | 3.2 | Deionized water | 120 | 1.00 | 4.2 | TTE (cycle ergometer) | 21 °C, 43%; airflow NS | 0.58* |
| Hillman et al. (2011b) [29] | 7 M, unacclimated, competitive cyclists | NS | EX (V); 34 °C; 90 min | 15 | 3.8 | Water | 105 | 1.00 | 7.2 | PO (cycle ergometer) | 34 °C | 0.60* |
| Kenefick et al. (2010c) [41] | 8 M | 46.3 ± 5.2 | EX; 50 °C; 3-h W/R | 120 | 4.0 | NaCl | 300 | 1.05 | 15 | TW (cycle ergometer) | 30 °C | 0.64* |
| Castellani et al. (1997) [62] | 8 M, unacclimated | 57.9 ± 4.5 | EX (M); 33 °C; 180 min | 135 | 4.1 | NaCl + NNS | 120 | 0.50 | 72 | TTE (treadmill walking) | 36 °C; 47%; 2.3 m/s | 0.68* |
| Walsh et al. (1994a) [33] | 6 M, endurance cyclists/ triathletes | 61.4 ± 4.4 | EX (V); 30 °C; 60 min | 0 | 1.8 | NaCl + NNS | 50 | 0.90 | 8.2 | TTE (cycle ergometer) | 30 °C; 60%; 0.8 m/s | 0.74* |
| Kenefick et al. (2010b) [41] | 8 M | 45.3 ± 4.6 | EX; 50 °C; 3-h W/R | 120 | 4.2 | NaCl | 300 | 1.05 | 15 | TW (cycle ergometer) | 20 °C | 0.79 |
| Kavouras et al. (2006) [77] | 8 M, acclimated, endurance cyclists | 61.4 ± 2.3 | FR + EX (M); 120 min | >12 h | 3.9 | Water + NNS | 80 | 0.75 | 23 | TTE (cycle ergometer) | 37 °C; 48%; 2.54 m/s | 0.81* |
| Kenefick et al. (2010d) [41] | 8 M | 43.7 ± 7.0 | EX; 50 °C; 3-h W/R | 120 | 4.1 | NaCl | 300 | 1.05 | 15 | TW (cycle ergometer) | 40 °C | 0.87* |
| Below et al. (1994) [63] | 8 M, acclimated, endurance trained | 62.9 ± 2.8 | EX (V); 31 °C; 50 min | 0 | 2.0 | NaCl + NNS | 50 | 1.00 | 11 | TT (cycle ergometer) | 31 °C; 54% | 0.89* |
| Casa et al. (2000) [76] | 8 M, unacclimated, endurance cyclists | 61.4 ± 2.3 | FR + EX (M); 120 min | >12 h | 3.9 | NaCl + NNS | 35 | 0.50 | 27 | TTE (cycle ergometer) | 37 °C; 2.3 m/s | 1.25* |
| Melin et al. (1994) [47] | 6 M, unacclimated, endurance trained | 57.5 ± 4.2 | HT | 60 | 2.6 | Water | NS | 0.50 | 97 | TTE (treadmill marching) | 35 °C; 20–30%; 0.8 m/s | 1.23* |
| Hasegawa et al. (2006) [64] | 9 M, untrained | 48.5 ± 4.5 | EX (M); 32 °C; 60 min | 4 | 1.6 | Water | 65 | 1.00 | 4.4 | TTE (cycle ergometer) | 32 °C; 80% | 4.01* |
Exercise intensity is described as high (H), vigorous (V) or moderate (M), in accordance with classifications outlined by Norton et al. [86]. Values are Hedges’ g effect sizes
Dh dehydration, EX exercise, FR fluid restriction, HT heat, NNS non-nutritive sweetener, NS not specified, PO power output, RH relative humidity, Total REC time from completing the dehydration protocol to commencing the subsequent task, TT time trial, TTE time to exhaustion, TW total work, W/R work rest cycle
*Significant difference between performances undertaken with and without fluid replacement (p < 0.05)