Table 1
References (alphabetical order)Number of subject, gender and ageExercise protocolAmbient temperature (°C)Relative humidity (%)Dehydration level (% bodyweight)
Ecologically valid exercise protocols
Bachle et al2610 recreationally-trained subjects, 4 men, 6 women, 29±6 years1-h self-paced laboratory-based cycling time-trial21°C72%Dehydrated group: −1.02%
Euhydrated group: +0.8%
Backx et al278 trained cyclists, 8 men, 0 woman, 29 ± 7 years1-h self-paced laboratory-based cycling time-trial20°C70%A. LF trial: −1.7%; FAM trial: −0.9%
B. MF trial: −1.3%; HF trial: −0.7%
C. LF trial: −1.7%; HF trial: −0.7%
D. MF trial: −1.34%; FAM trial: −0.88%
Dugas et al286 highly-trained cyclists, 6 men, 0 woman; 23±4 years80 km long cycling time-trial33°C50%A. 0 trial: −4.3%; 100 trial: −0.5%
B. 33 trial: −2.9%; 100 trial: −0.5%
C. Ad Lib trial: −2.1%; 100 trial: −0.5%
D. 66 trial: −1.9%; 100 trial: −0.5%
E. WET trial: −3.9%; 100 trial: −0.5%
Kay and Marino297 healthy cyclists, 6 men, 1 woman, 21±3 years1-h self-paced laboratory-based cycling time-trialModerate F vs NF: 19.8°C; Warm F vs NF: 33.2°CAll trials: 63%A. Warm NF trial: −2.2%; Warm F trial: 0%
B. Moderate NF trial: −1.8%; Moderate F trial: 0%
Robinson et al318 endurance-trained subjects, 8 men, 0 woman, 26±4 years1-h self-paced laboratory-based cycling time-trial20°C60%Dehydrated group: −2.3%
Euhydrated group: −0.9%
Non-ecologically valid exercise protocols
Below et al198 endurance-trained subjects, 8 men, 0 woman, 23±3 years50-min of laboratory-based cycling at 80% ˙O2peak, followed by a laboratory-based cycling test requiring the completion of a set amount of work (~165 000 J) in the shortest time possible31°C54%A. Placebo trial: −2.0%; Fluid trial: −0.5%
B. Carbohydrate trial: −1.8%; Carbohydrate + fluid trial: −0.5%
Ebert et al208 well-trained cyclists, 8 men, 0 woman, 28±6 years2-h of laboratory-based cycling at 53% of maximal aerobic power output, followed by a laboratory-based cycling hill-climb time-to-exhaustion trial at 88% of maximal aerobic power output at an incline of 8%29°C37%Dehydrated group: −3.1%
Euhydrated group: −0.5%
Edwards et al2111 moderately active soccer players, 11 men, 0 woman, 24±3 years1) 45-min of laboratory-based cycling at 90% of individual ventilatory threshold +; 2) a 45-min outdoor soccer match and; 3) a YO-YO intermittent recovery test1) 45-min laboratory-based cycling test: 24.5°C; 2) 45-min soccer match: 20°C1) 45-min laboratory-based cycling test: 51%; 2) 45-min soccer match: 52%A. MR trial: −2.1%;FL trial: −0.7%
B. NF trial: −2.4%; FL trial: −0.7%
Fallowfield et al328 subjects, 4 men, 4 women, 21±2 yearsTreadmill run at 70% ˙O2peak, until exhaustion20°C50%Dehydrated group: −2.0%
Euhydrated group: −0.8%
Maughan et al3312 healthy subjects; 12 men, 0 woman, 24±3 yearsLaboratory-based cycling test to exhaustion at 70% ˙O2peak,21°C21%B. Dehydrated group: −1.9%
Euhydrated group: −0.6%
Maughan et al346 healthy subjects; 6 men, 0 woman, 29±5 yearsLaboratory-based cycling test to exhaustion at 70% ˙O2peak,22.5°C45%A. Dehydrated group: −1.8%
Euhydrated group: −0.7%
McConell et al308 well-trained cyclists and triathletes, 8 men, 0 woman, 26±3 years45-min of laboratory-based cycling at 80% ˙O2peak, followed by a laboratory-based cycling time-trial in which subjects had to complete as much work as possible during 15 min21°C41%2a. FR-50 trial: −1.0%; FR-100 trial: 0%
2b. NF trial: −1.9% FR-100 trial: 0%
2c. NF trial: −1.9% FR-50 trial: −1.0%
McConell et al227 well-trained cyclists and triathletes, 7 men, 0 woman, 24±3 years2-h laboratory-based cycling at 69% ˙O2peak, followed by a laboratory-based cycling test to exhaustion at 90% ˙O2peak,21°C43%1a. NF trial: −3.2%; FR-100 trial: −0.1%
2b. FR-50 trial: −1.8%; FR-100 trial: −0.1%
Van Schuylenbergh et al239 highly-trained endurance athletes, 9 men, 0 women, 26±6 years1) 20-min laboratory based cycling warming-up period +; 2) 2-h of laboratory-based incremental cycling test to exhaustion +; 3) 2-h of laboratory-based intermittent cycling (mean intensity of 70% ˙O2peak, and; 4) a laboratory-based incremental cycling test to exhaustion20°C60%Dehydrated group: −3.3%
Euhydrated group: −0.7%
Walsh et al246 endurance-trained competitive cyclists or triathletes, 6 men, 0 woman, 26±4 years1-h of laboratory-based cycling at 70% ˙O2peak, followed by a laboratory-based cycling test to exhaustion at 90% ˙O2peak,32°C60%Dehydrated group: −1.8%
Euhydrated group: −0.2%
  • Ad Lib, ad libitum drinking; F, fluid; FAM, familiarisation; FL, fluid; FR, fluid replacement; HF, high fluid; LF, low fluid; MF, medium fluid; MR, mouth rinsing only; NF, no fluid; WET, mouth rinsing only; 0, no fluid; 33, 33% fluid replacement; 66, 66% fluid replacement; 100, 100% fluid replacement.