Coaching Corner: STAYING HYDRATED DURING EXERCISE

January has arrived.  The start of a new year often brings resolutions.  Hopefully, your resolutions involve stepping up your fitness program, which may have lagged during the busy holiday season, or even beginning fresh with a new program that may be long overdue.  There are a lot of components to consider when putting together your plan, but no matter what type of exercise regiment you decide on, make sure to incorporate proper hydration into your program.

Proper hydration is one of the most important aspects of healthy physical activity. Drinking the right amount of fluids before, during and after every physical activity is vital to providing your body the fluids it needs to perform properly.
There are several variables that determine how much water you need during a workout.  Below are some points to consider.  For purposes of this discussion we will be focusing on hydration during an average fitness workout of 60 minutes.  If you are performing workouts longer than 60-90 minutes in duration, training for a marathon, triathlon, or other special event, you will need to seek hydration guidelines for those specific situations.

Air Temperature and Humidity: The higher the temperature rises, the greater your sweat losses. In fact, during intense exercise in hot and humid conditions, we can sweat up to 3 liters, which is almost all of the water in the bloodstream. To replace the water that is lost from the bloodstream, the body takes water from its tissues or uses the fluids that you drink during and after exercise.  But in humid conditions, sweat takes longer to evaporate from the skin because the air already contains a lot of water. So, in these humid conditions, the body tries to cool itself by sweating even more. If you do not replenish the water that your body loses, you will become dehydrated.  The amount of water your body needs to stay hydrated depends on your body weight, body temperature, and the type of exercise you are doing. If you are dehydrated after an exercise session, it will take time to replenish the body's water. Drink several glasses of water spaced out throughout the day.

Intensity: The harder you work out, the more you perspire.

Body Size and Gender: Larger people sweat more. Men generally sweat more than women.

Duration: The longer the workout, the more fluid you lose.

Fitness Level: Well-trained athletes perspire more than less fit people.  The reason is that athletes cool their bodies through sweat more efficiently than most people because their bodies are used to the extra stress. As a result, fluid needs are higher for highly trained athletes than for less fit individuals.

Other Beverages: Do not drink juices or sodas during exercise, because these drinks contain more than 10% carbohydrates (sugar) and are not absorbed well during exercise.  Sports drinks usually contain less than 8% carbohydrates, but these can lead to too many calories if you drink too much of them. The best way to hydrate is simply water.  If you’re exercising for less than an hour, water is all you need to keep you hydrated. If you’re exercising for longer than an hour, sports drinks can provide extra fuel.

Hydration Pre-Exercise:

Drink about 16 ounces of water 1 to 2 hours before you exercise.

Drink about 8-12 ounces of water 15 minutes before you exercise.

Hydration During Exercise:  For workouts of less than 90 minutes the rule of thumb is to drink 8 ounces of water over each 20-minute period.  Drink cool water rather than cold water, because the body absorbs cool water faster.  Replace fluids regularly during exercise. Drinking water is the only way to rehydrate and cool your body from the inside out.

• Drink about 4-5 ounces water every 10 minutes during exercise.


• Have about 34 ounces (1 L) of water on hand per hour.

Remember that you need to be replacing the fluid you lose while you are exercising, do not wait until you finish. The sooner you start to replace the fluid the sooner you will recover.
Hydration Post-Exercise:

Drink about 16 ounces of water just after exercise.  Post-exercise hydration gets your fluid levels back to normal and can help with recovery.  Sports drinks that include sugar or salt in them will help you increase the fluid that goes into the body.  They also can replenish the salt and minerals lost through sweating, although a healthy diet is usually adequate for this.

*Do not take salt tablets. Salt tablets make dehydration worse because they drain the water from your body.

Dehydration can cause fatigue, headaches, muscle cramps, dizziness and lead to heat exhaustion or even heat stroke.  It also can raise your heart rate as the body works harder to stay cool.  Even if you’re just a little dehydrated, it can decrease your performance.  Dehydration can occur during any type of physical activity. It doesn't have to be hot. You don't have to have visible perspiration. You can become dehydrated indoors, in a pool or lake, or skiing on a winter day.

Since dehydration that exceeds 2 percent body weight loss reduces exercise performance, it is advised to begin exercise well hydrated, replenish fluids regularly during exercise and replace fluid losses after exercise.

Be alert for conditions that increase your fluid loss through sweat (high temperature, high humidity, very high intensity, for example).

Remember swimmers sweat, too. Like any athletic activity, when you swim, your body temperature rises and your body sweats to keep from overheating. You may not notice because you are in the water, but you can become dehydrated. Swimmers, athletic or recreational, need to drink fluids before, during and after swimming, even if you don't feel thirsty.