In-Gym Hydration Study Summary
Stover, B. et al. 2003. Canadian Journal of Applied Physiology, 28 suppl s105.
Results Summary
A study indicates nearly half of all exercisers arrive at the gym already dehydrated—even though many mistakenly believe they are drinking enough.
Key findings from the study reveal
- Nearly half of all exercisers were dehydrated before starting their workout.
- Men show a trend towards being more likely than women to start their workout dehydrated.
- Of the total number of exercisers that were dehydrated:
- More than 90% work out three or more times a week.
- Nearly 75% planned to work out for an hour or more.
- More than half thought they were properly hydrated.
- Nearly 50% admit it's a struggle for them to drink enough throughout the day.
- More than two-thirds drink plain water, and nearly one-third say they drink nothing.
Implications
Dehydration can negatively impact an exerciser’s physical1 and cognitive2 performance; therefore, arriving at the gym already dehydrated puts exercisers at a real disadvantage for their workouts and achieving their fitness goals.
To get the most out of workouts, many exercisers need to pay special attention to what and how much they drink for optimal hydration before, during and after exercise.
Recommendations
Research has shown that exercisers tend to replenish only about 50% of the fluids they lose during a workout when they drink plain water.3 One reason is that the lack of taste and flavor of plain water makes it challenging for exercisers to drink enough to stay properly hydrated.
Research also shows that people will drink more of a lightly flavored beverage than plain water,4 and will therefore stay better hydrated before, during and after working out.
Study Background
The In-Gym Hydration study was conducted by scientists from the Gatorade Sports Science Institute at Bally's Total Fitness locations in Chicago and Los Angeles.
More than 300 subjects’ pre-workout hydration status was predicted by conducting a urine specific gravity test (USG), a measure of the weight of urine relative to its volume (grams/milliliter).*
* When a person is dehydrated, the weight rises relative to the volume of urine produced. Therefore, the urine of a dehydrated person is heavier, or more concentrated, when compared with the same volume of urine from a hydrated individual. Most experts in the scientific community recognize 1.02 g/ml as the cutoff for being hydrated,5 meaning individuals with a USG of 1.02 g/ml or lower are most likely hydrated, while individuals with a USG over 1.02 g/ml are most likely dehydrated. USG can be affected by a number of physiological and behavioral factors, and therefore provides a prediction of hydration status rather than an exact measure.
For More Info
To learn more about the importance of hydration as well as receive customized fluid intake recommendations for workouts, visit www.propelfitnesswater.com or www.gatorade.com. For more information on hydration and exercise science, please visit the Gatorade Sports Science Institute at www.gssiweb.com.
1 Sanchez and Pandolf. 1990. Perspectives in Exercise Science and Sports Medicine. Vol. 3, 15.
For more information, please visit www.propelfitnesswater.com.