The average adult population doesn’t exercise like a competitive athlete, so you might assume there’s no need to keep track of water intake. However, your hydration status can determine whether or not you have the energy to make it through your next training session. Dehydration increases your body’s core temperature and can raise your heart rate, increasing how you perceive your level of effort. This translates to premature fatigue, and can make you want to throw in the towel. In addition, both dehydration and over-hydration can cause stomach discomfort such as cramps as well as feelings of nausea. These are just some of the reasons why you should be more aware of your hydration status.

Sweat


As an active adult, it’s important to drink enough each day to replenish what is lost through sweat. Sweating is your body’s way of regulating body temperature. Sweat contains water and essential electrolytes such as sodium and potassium. Sweat rates and the electrolyte content of sweat will vary amongst individuals. Some of the factors that determine how much you sweat are your metabolic rate, the amount and type of clothing worn, as well as environmental conditions such as temperature and humidity. Elevations in body temperature will generally cause you to sweat more. Exercising vigorously in hot weather can cause substantial sweat loss and because sweat evaporates, you may not even notice you are sweating as much as you really
are.

How to Monitor Hydration Status


Minimize those feelings of tiredness and maximize your performance for your next training session by making sure you are hydrated. Thirst alone isn’t a good indicator of your hydration status because feelings of thirst usually mean you’re already dehydrated. To avoid a decrease in performance as well as any negative changes in health status, try to keep weight fluctuations to a minimum.

Weighing yourself before and after exercise can help you stay on track. In addition to helping you determine your sweat rate, a quick weigh-in before an exercise session will give you a baseline to check with after you have completed the session. Weighing yourself after an exercise session can tell you how much sweat was lost during a physical activity session. Use this information to estimate fluid replacement needs. In general, you should strive to drink about 16 ounces or 2 cups of water for every pound of weight that you’ve lost after an exercise session.

Another method of monitoring your hydration status is by checking the color and quantity of your urine. It sounds unappealing, but this method is both simple and effective. A clear or pale yellow color typically indicates you’re hydrated. If you notice a yellow to dark yellow color, then you probably need to drink more water. Also, the amount of urine should be plentiful. If you notice a lack of, or are not going as much as you normally do, then you probably need to drink more water.

Over-Hydration


The benefits of hydration are many, however, it’s also possible to overhydrate. Overhydration is sometimes called water intoxication and can lead to a condition called hyponatremia. Hyponatremia simply means that an individual’s sodium levels become too low because of dehydration. You can lose too much salt through sweat or by over drinking fluids that do not contain enough sodium to replace what is lost.

Fortunately, consuming beverages that contain electrolytes can reduce the risk of falling victim to hyponatremia. Some fitness waters, sports drinks, and recovery drinks contain electrolytes that can help replenish lost sodium and potassium. Individuals who are relatively unfit, use diuretic medication for high blood pressure, are on a salt-free or low-sodium diet, or are exercising for more than one hour in hot and humid weather, should consider drinking fluids containing electrolytes.

What to Drink


Flavored drinks tend to be more palatable, and those with added salt will increase the likelihood of voluntary rehydration. This strategy is most beneficial for individuals who exercise in hot weather, for prolonged periods (longer than an hour). Studies have shown that adding moderate amounts of sodium to a beverage does make rehydration a lot easier. However, don’t forget to pay attention to the Nutrition Facts Label, especially the amount of calories in a single serving. Sports drinks, recovery drinks, energy drinks, and even some fitness waters do provide calories in small amounts, with many containing more than one serving per bottle. So, watch out, and try to keep the liquid calories to a minimum. Over time these calories do add up and can eventually hinder your weight and fat loss efforts.

Hydration Chart

Adapted from: McArdle WD, Katch FI, Katch VL. Sports and Exercise Nutrition. Lippincott Williams & Wilkins; 2005: 297.

General Recommendations for Fluid Replacement


According to the Institute of Medicine, sedentary men should strive to drink approximately 3 liters (about 13 cups) of liquids, and women should try to drink about 2 liters (about 9 cups) of liquids. As the level of physical activity and environmental temperature increases, the more you will probably need to drink to stay hydrated. Over the course of a day, these recommendations are very achievable. Make this task less daunting by carrying a marked bottle such as a one liter water bottle or other marked bottle. Remember that intake can include fluid from food, milk, tea, coffee, soup, fruit juice, and sports beverages.

For those of you engaging in physical activity, both the National Athletic Trainer’s Association and the American College of Sports Medicine have recommendations that coincide, such as rehydration before, during, as well as after exercise activity. So give your next training session 100 percent and maximize calorie burn by following these simple tips:

  • Before your exercise session begins, consume about 1.5 to 2.5 cups of fluids about 2 to 3 hours before your exercise session begins. This will give you more than enough time to absorb the fluids and to ensure adequate urine output.
  • During your exercise session, drink about 1 ounce (think of a couple of sips) of fluid for every 20 minutes of exercise. Communicate with your personal trainer and ask for a water break! If you are exercising for less than an hour, and in an air conditioned facility, you probably do not need to drink anything other than plain water.
  • After your exercise session, drink about 2 to 3 cups of fluid for each pound that has been lost. Electrolyte deficits can usually be replenished on their own through the consumption of normal meals and beverages. If you need to, beverages can be in the form of a sports
    drink and can include a blend of sodium, carbohydrates, and protein. This will help maximize your recovery.

Monitoring and drinking the right type of fluids is an essential component of a healthy lifestyle. Staying hydrated can help you keep your energy levels elevated and can help you avoid symptoms such as cramping and nausea. While sweating helps you regulate your body’s internal temperature it also contains water and essential electrolytes that need to be replaced, during and after prolonged, high intensity exercise, as well as during hot and humid weather. Get better at monitoring your hydration status by keeping track of your body weight before and after exercise with a quick weigh-in, and by observing the color and quantity of your urine output. Drinking fluids before, during, and after an exercise training session will help ensure a normal hydration status. Finally, pay attention to Nutrition Facts labels and watch out for unnecessary calories in fitness waters, sports drinks, recovery drinks, and energy drinks. Most of the time you will find that just drinking plain water will do the job.

References


1. McArdle WD, Katch FI, Katch VL. Sports and Exercise Nutrition. Lippincott Williams &
Wilkins; 2005.

5. Kenefick, RW and Cheuvront, SN. (2012), Hydration for recreational sport and physical
activity. Nutr Rev 2012, 70: S137–S142.

2. Mountain, SJ. Hydration Recommendations for Sport 2008. Curr Sports Med Rep. 2008; 7(4):
187-192.

3. Mayo Clinic website. http://www.mayoclinic.com/health/water/NU00283 Accessed, February
7, 2013.

4. Manore MM. Exercise and the Institute of Medicine recommendations for nutrition. Curr
Sports Med Rep 2005; 4(4):193-8.

6. Casa DJ, Armstrong LE, Montain SJ, Rich BS, Stone JA. National athletic trainers association
position statement: fluid replacement for athletes. J Athl Train. 2000; 35(2): 212-214.

– BY MICHAEL METCHIKIAN | IN NUTRITION | ON FEBRUARY 25, 2013