Table 2.
Characteristics of research studies evaluating athletic performance on intermittent exercise tasks
| Citation | Participants | VO2 max | Dh protocol (EX intensity); ambient temperature; duration | Total REC (min) | Dh trial BM loss (%) | Fluid type | Fluid assimilation time (min) | Fluid intake (L kg BM lost−1) | Intermittent exercise task | Ambient temperature; RH; airflow | Performance outcomes(s) | Performance outcomes significantly affected (Hedges’ g) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Walsh et al. (1994b) [33] | 6 M, endurance cyclists/triathletes | 61.4 ± 4.4 | EX (V); 30 °C; 60 min | 15 | 1.8 | NaCl + NNS | 65 | 0.90 | aIST | NS | Max. velocity; lower limb force | No effect |
| Maxwell et al. (1999) [65] | 11 M, untrained | NS | EX (M); 32 °C; 48 min | 120 | 1.5 | NaCl + NNS | 208 | 1.55 | bMART | 32 °C; 73% | Sprint duration | ↑ (0.19) |
| Devlin et al. (2001a) [71] | 7 M, sub-elite cricketers | 56 ± 6 | EX; 28 °C; 60 min | 0 | 2.8 | Water | 60 | 0.80 | cMMRT | 16 °C; 60% | 20-m shuttle runs | ↑ (0.30) |
| Cheuvont et al. (2006) [51] | 8 M, physically active | 52 ± 6 | HT | Testing at 0, 30 and 60 | 2.7 | Water | 185–240 | 1.00 | 15 s WAnT | 22 °C; 65% | Abs. mean PO; Rel. mean PO; Abs. PPO; Rel. PPO; rate of fatigue |
No effect |
| Edwards et al. (2007a) [58] | 11 M, moderately active soccer players | 50.9 ± 4.0 | EX; 19-25 °C; 90 min | 0 | 2.4 | Water | 90 | 0.80 | dYo-Yo Test | NS | Distance covered | ↑ (ES unknown) |
| Maxwell et al. (2009a) [22] | 8 M, unacclimated, game players | 59.9 ± 8.0 | EX (H/M); 36 °C; 90 min | >12 h | 3.9 | Water | >12 h | 1.50 | eIST | 36 °C; 49% | TW; Abs. PPO; Rel. PPO (during the IST, RSB 1 and RSB 2) |
TW (0.97) and Abs. PPO (0.79) ↑ on RSB 2 only. |
| Maxwell et al. (2009b) [22] | 8 M, unacclimated, game players | 59.9 ± 8.0 | EX (H/M); 36 °C; 90 min | >12 h | 3.9 | Water | >12 h | 1.00 | eIST | 36 °C; 49% | TW; Abs. PPO; Rel. PPO (during the IST, RSB 1 and RSB 2) |
No effect |
| Kraft et al. (2011) [75] | 10 M | NS | WI | 45 | 3.0 | Water | 158–178 | 1.00 | fIST | NS | Abs. mean PO; Abs. PPO; s >90 rpm; Rate of fatigue |
No effect |
| Owen et al. (2013a) [59] | 13 M, semi-professional soccer players | 54 ± 3 | EX; 19 °C; 105 min | 5 | 2.5 | Water | 110 | 0.89 | dYo-Yo Test | 19 °C; 59% | Distance covered | No effect |
| Owen et al. (2013b) [59] | 13 M, semi-professional soccer players | 54 ± 3 | EX; 19 °C; 105 min | 5 | 2.5 | Water | 110 | 0.51 | dYo-Yo Test | 19 °C; 59% | Distance covered | No effect |
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
Abs. absolute, Dh dehydration, ES effect size, EX exercise, HT heat, IST intermittent sprint test, MART maximal anaerobic running test, Max. maximum, MMRT maximal multistage running test, NNS non-nutritive sweetener, NS not specified, PO power output, PPO peak power output, RH relative humidity, Rel. relative, Total REC time from completing the dehydration protocol to commencing the subsequent task, TW total work, WAnT Wingate Anaerobic Test, WI warm water immersion
aThe intermittent sprint test (IST) comprised of five 5-s sprints at 3-min intervals on a cycle ergometer
bThe maximal anaerobic running test (MART) involved repeated 20-s runs on a treadmill, at increasing intensities, with 100-s passive recovery between runs until volitional exhaustion
cThe maximal multistage running test (MMRT) involved repeated 20-m runs between two points, at increasing intensity
dThe Yo-Yo intermittent recovery test is a soccer-specific performance test that comprises of 20-m shuttle runs separated by 10 s jog recovery. Running speed during the test is incremental, and maximal performance is indicated by total distance covered
eThe IST comprised of a 36-min repeated sprint exercise divided into 2-min periods of a 4-s sprint and 100 s of active recovery (35% VO2 max) and 16 s passive rest. A repeated sprint bout (RSB) involving 5 × 2 s sprints with 18 s active recovery was also completed after the 8th and 16th sprints (RSB 1 and RSB 2). All testing was completed on a cycle ergometer
fThe IST comprised of a 3-min warm up followed by 6 × 15 s maximal sprints separated by 30 s active recovery on a cycle ergometer