The definition of “proper hydration” not only varies from person to person, but also depends on the circumstances. Given the abundance of fluid choices on the market, we certainly understand why people question what is best and how much to have.
As the duration of our exercise session increases, especially if we are working out in the heat, the more likely we are to benefit from more than just plain water. In addition to replenishing fluid, we need to replace the electrolytes lost in sweat and the carbohydrates we metabolize for energy. Juice usually does not cut it, as the sodium concentration is too low and the abundance of fructose can cause gastrointestinal distress. For many athletes, sports drinks are the answer.
Commercial products, such as Gatorade and PowerAde, are popular options as is coconut water. Most of these offer a balanced blend of sugars, which increases gastrointestinal tolerance and absorption rate. One drawback to coconut water, however, is low sodium content. Many athletes, especially those whose sweat leaves white salt marks on their clothing, may benefit by adding extra salt to their coconut water.
We can typically control what we drink during training and sports where we can keep our beverage of choice on the sidelines, but the same is not always true during endurance events. Fuel belts and fluid backpacks can help, but their weight and bulk can hinder performance. Sometimes we are at the mercy of whatever the race director gives us. In this case, find out in advance (Check the race’s website and/or contact the race director.) what will be provided and practice with it in your training. If you perform well with it, great; if not, use the time to formulate a Plan B. For example, station along the route friends who can hand you your beverage of choice as you pass by.
Remember that perhaps no area of nutrition is more individualized than sports nutrition, so experiment during your training to figure out what has you performing your best. To the fullest extent possible, avoid drinking anything during competition that you have not tolerated during practice.
Why do we need water? Well, the wet stuff is for more than just quenching your thirst; every system in the human body depends on it (and your body is made up of 60-75% water). You need water to regulate your body temperature, lubricate your joints, flush toxins from your body, protect body organs and tissues, and carry nutrients and oxygen to cells. So, clearly, we need water to live!
I’m sure many of you have heard the advice “drink eight 8-ounce glasses of water each day,” and while that figure is not too off-target, it’s not a hard and fast rule. The Institute of Medicine determined that an adequate fluid intake for women is about 2.2 liters (approximately 9 cups) of total beverages a day; for men, it’s about 3 liters, or 13 cups. To reach these amounts, you can include the water that naturally occurs in many fruits and vegetables, soups, and beverages other than water, as all fluids count toward this daily total.
Of course, the above figures are averages, not exact numbers. Adequate hydration varies from person to person. Some people simply need more fluids, while others need less. To assess hydration status, I often tell my patients to look at their urine, as it can be an excellent indicator of dehydration. If your urine is very light yellow, almost clear, you are adequately hydrated. Dark yellow? Then you most likely need to up your fluids. In the end, pay attention to your body’s thirst cues – your body has more wisdom than you think.