Table 3.
Summary of studies measuring effects of hypohydration on physical performance (i.e., sprinting, jumping, lateral movements, and intermittent high-intensity running capacity) in team sports
| Reference | Sport | Subjects | Protocol | Hydration levels (% ∆ body mass) | Physiological and subjective measures | Effect of hypohydration on physical performance | Potential study limitations |
|---|---|---|---|---|---|---|---|
| Ali et al. 2011 [106] | Soccer |
n = 10, 26 y female Premier division players |
LIST protocol (90 min) with water intake (total of 15 ml/kg) or no fluid 15-m sprints performed throughout LIST protocol Env conds: NA |
−2.2% (no fluid), −1.0% (water intake) |
Blood lactate, HR, RPE, and Tc higher in no fluid trial NS: pleasure/displeasure (Feeling Scale), perceived activation (Felt Arousal Scale) |
NS: Mean sprint time | Subjects not blinded to hydration status No control (EUH) trial |
| Ali and Williams 2013 [113] | Soccer |
n = 8, 24 y male university players |
LIST protocol (90 min) with water intake (total of 15 ml/kg) or no fluid 15-m sprints performed throughout LIST protocol Env conds: NA |
−3.7% (no fluid), −2.3% (water intake) |
RPE higher in no fluid trial NS: HR and Tc; isometric strength, isokinetic strength, and muscle power of the knee flexors and knee extensors |
NS: Mean sprint time | Subjects not blinded to hydration status No control (EUH) trial |
| Edwards et al. 2007 [94] | Soccer |
n = 11, 24 y male moderately active players |
45 min cycling, then 45 min soccer match with water intake (80% replacement of fluid losses), water mouth rinse, or no fluid Yo–Yo intermittent recovery test performed after match Env conds: Cycling: 24–25 °C, 47–55% RH Match: 19–21 °C, 46–57% RH |
−2.4% (no fluid), −2.1% (mouth rinse), −0.7% (water intake) |
Tc higher during match in no fluid vs. water intake trial RPE higher during no fluid vs. water intake and mouth rinse trials |
Less distance covered during the Yo–Yo test in no fluid (by 13%) and mouth rinse trials (by 15%) vs. water intake trial | Subjects not blinded to hydration status Cycling exercise prior to match not realistic to soccer |
| McGregor et al. 1999 [95] | Soccer |
n = 9, 20 y male semiprofessional players |
LIST protocol (90 min) with fluid intake (total of 15 ml/kg, sugar-free lemon drink) or without fluid 15-m sprints performed throughout the LIST protocol Env conds: 13–20 °C, 57% RH |
−2.4% (no fluid), −1.4% (fluid intake) |
HR and RPE higher during no fluid trial | Mean sprint time was longer in the last 15-min block of the LIST protocol during the no fluid trial vs. fluid intake trial | Subjects not blinded to hydration status No control (EUH) trial |
| Owen et al. 2013 [105] | Soccer |
n = 13, 22 y male semiprofessional players |
LIST protocol (90 min) with prescribed water intake (to replace 89% of sweat losses), ad libitum water intake, or no fluid Yo–Yo intermittent recovery test performed before and after LIST protocol Env conds: 19.4 °C, 59.4% RH |
−2.5% (no fluid), −1.1% (ad libitum water intake), −0.3% (prescribed water intake) |
RPE higher during no fluid vs. prescribed water intake HR higher during no fluid vs. prescribed water intake and ad libitum water intake |
NS: Distance covered during the Yo–Yo test | Subjects not blinded to hydration status |
| Burke and Ekblom 1984 [112] | Tennis |
n = 10, 5 male (21–32 y) and 5 female (30–40 y) healthy, active tennis players |
Water (505 ml) or no fluid intake during 2-h simulated tennis matches Sargent jump test (explosive power) performed before and after the matches Env conds: Indoors, 23–25 °C |
−2.7% (no fluid), −1.1% (water intake) |
NA | NS: maximum jump height and anaerobic power | Subjects not blinded to hydration status No control (EUH) trial |
| Baker et al. 2007 [102] | Basketball |
n = 17, 17–28 y male competitive players |
3 h interval walking in heat chamber (to establish 1–4% or maintain EUH) prior to 80-min simulated game Subjects drank water to maintain target HYPO level or flavored water in EUH trial Sprinting, lateral movement (defensive slides), and combination, and jumping drills completed throughout a simulated game Env conds: Heat chamber: 40 °C, 20% RH Game: indoors, temperate |
−1%, −2%, −3%, and −4% (HYPO trials), 0% (EUH trial) |
More leg fatigue and lightheaded in 3% and 4% HYPO trials vs. EUH trial More upper and total body fatigue in 4% HYPO trial vs. EUH trial Higher Tc during 2nd quarter of 4% HYPO trial vs. EUH trial NS: RPE and HR |
Longer total sprint time in 2% (by ~7%), 3% (by ~8%), and 4% (by ~16%) HYPO trials vs. EUH Longer lateral movement time in 3% and 4% HYPO trials vs. EUH trial Longer combination drill time in 3% and 4% HYPO trials vs. EUH trial Longer repeated jump time in 4% HYPO trial vs. EUH trial NS: maximum vertical jump |
Subjects not blinded to hydration status Exercise-heat stress prior to simulated game not realistic to basketball No validity or reliability testing of simulated game/basketball drills |
| Carvalho et al. 2011 [60] | Basketball |
n = 12, 14–15 y male players on Portuguese national team |
90-min training session with ad libitum water or no fluid Basketball drills performed before and after the training session Env conds: Indoors, 21.9–26.0 °C, 48.3–54.1% RH |
−2.5% (no fluid), −1.1% (ad libitum water intake) |
RPE higher in no fluid trial | NS: Sprinting and defensive slide times | Subjects not blinded to hydration status No control (EUH) trial No validity or reliability testing of the basketball drills |
| Dougherty et al. 2006 [103] | Basketball | n = 15, 12–15 y male competitive players | 2-h interval walking/cycling in heat chamber (to establish 2% HYPO or maintain EUH) prior to 60-min simulated game Subjects drank water to maintain 2% HYPO or flavored water in EUH trial Sprinting, lateral movement (defensive slides), combination, and jumping drills completed throughout a simulated game Env conds: Heat chamber: 35 °C, 20% RH Game: indoors, temperate |
−2% (HYPO trial), 0% (EUH trial) |
More upper body fatigue and higher HR and Tc in HYPO trial vs. EUH trial NS: RPE and total body fatigue |
Longer total and mean sprint times (by ~6%) and lateral movement times (by ~7%) in HYPO trial vs. EUH trial NS: combination drill time, maximum jump height, repeated jumping time |
Subjects not blinded to hydration status Exercise-heat stress prior to simulated game not realistic to basketball No validity or reliability testing of simulated game/basketball drills |
| Hoffman et al. 1995 [101] | Basketball |
n = 10, 17 y male players on Israel regional youth team |
Water intake or no fluid during 2-on-2 full court games Squat jump, countermovement jump, and 30-sec anaerobic power jump test performed before, at halftime, and immediately after games Env conds: Indoors, 20.8 °C, 64% RH |
−1.9% (no fluid), NA (water intake permitted) |
NS: RPE or HR | NS: maximum vertical jump height during squat jump and countermovement jump, 30-s anaerobic power jump test However, anaerobic power during the 30-sec jump test was 19% lower in the no fluid vs. water intake trial after the game |
Subjects not blinded to hydration status Unclear whether water intake trial was ad libitum or a control (EUH) trial No validity or reliability testing of 2-on-2 basketball game |
| Hoffman et al. 2012 [96] | Basketball |
n = 10, 21 y female division 1 college players |
Water to replace fluid losses or no fluid intake during a 40-min live scrimmage Countermovement jump performed before and after the scrimmage Env conds: Indoors, 22.6 °C, 50.9% RH |
−2.3% (no fluid), NA (water intake) |
NS: HR and player load (Catapult GPS) | NS: Peak and mean power during countermovement jump | Subjects not blinded to hydration status No validity or reliability testing of the reactive agility test |
| Devlin et al. 2001 [109] | Cricket |
n = 7, 21 y male, well-trained, skilled bowlers |
Fluid restriction (30 ml flavored, colored ice blocks) or prescribed fluid intake (80% replacement of losses via flavored, colored water) during 1 h intermittent exercise Maximal multi-stage shuttle run performed before and after exercise Env conds: Exercise: 28 °C, 40% RH Skills test: 16 °C, 60% RH |
−2.8% (HYPO trial), −0.5% (EUH trial) |
RPE higher during HYPO trial at post-exercise bowl test NS: HR |
Fewer shuttles completed after intermittent exercise in HYPO trial vs. EUH trial (by 7.7%) | Subjects not blinded to hydration status No validity or reliability testing of the shuttle run |
| Gamage et al. 2016 [83] | Cricket | n = 30, 22 y male elite cricketers (8 batsmen, 10 fast-bowlers and 12 fielders) |
Fluid restriction (4 ml/kg/h) or fluid provision (12–15 ml/kg/h) during 2 h of standardized cricket training Cricket batter running test (timed running between wickets) before and after training Env conds: Outdoors: 27.2–32.8 °C, 66–89% RH, ~2 mph wind speed |
−3.7% (fluid restriction trial), −0.9% (fluid provision trial) |
NA | Run time increased (slower performance) from pre- to post-training (by 2.2%) in the fluid restriction trial Run performance was maintained from pre- to post-training in the fluid provision trial |
Subjects not blinded to hydration status Type of fluid provided not reported No validity or reliability testing of the cricket running test |
| Davis et al. 2015 [114] | Baseball |
n = 8, 21 y male college players |
Dehydration protocol (~90-min treadmill walking in the heat), followed by controlled rehydration to EUH or 3% HYPO. Intermittent sprinting (3 bouts of 8 × 30-m sprints with 30 s rest between sprints and 3 min between bouts) performance measured the morning after establishing EUH or HYPO Env conds: Treadmill walking: 38–39 °C, 30–40% RH Sprint performance: 22 °C, 25–32% RH |
−3% (HYPO trial), 0% (EUH trial) |
Higher HR and RPE in HYPO trial vs. EUH trial during bout 2 and 3 NS: HR and RPE during bout 1 |
Longer mean sprint time in HYPO trial vs. EUH trial during bout 2 (by ~3%) and bout 3 (by ~4%) NS: mean sprint speed during bout 1 |
Subjects not blinded to hydration status No measure of sprint performance at baseline (pre-HYPO) Dehydration protocol was on a treadmill and therefore not sport-specific |
| Yoshida et al. 2002 [85] | Baseball |
n = 7, 21 y male college players |
Sports drink (3.6% CHO) consumed at a volume equivalent to 20, 40, 60, and 80% of sweat losses during a usual practice (3.8 h) 10 s maximal anaerobic power output during cycling measured before and after baseball practice Env conds: 29.2 °C WBGT |
−3.9% (20% replaced), −2.5% (40% replaced), −1.7% (60% replaced), −0.7% (80% replaced) |
NA | Maximal anaerobic power decreased (by ~13% from baseline) with −3.9% ∆BM NS: change in maximal anaerobic power with −0.7%, −1.7%, or −2.5% ∆BM |
Subjects not blinded to hydration status Practice sessions not standardized between trials Potential confounding effect of CHO |
Values are means or ranges where specified
BM body mass, CHO carbohydrate, Env conds environmental conditions, EUH euhydration, GPS global positioning system, HR heart rate, HYPO hypohydration, LIST Loughborough Intermittent Shuttle Test, mph miles per hour, NA not available, NS no significant effect, RH relative humidity, RPE rating of perceived exertion, Tc body core temperature, WBGT wet bulb globe temperature