Race Fueling

Hydration Tips For Triathletes



Photo: Nils Nilsen


If you find that you’re dehydrated (see the simple tests below), increase your daily fluid intake using an assortment of beverages. It’s easier for your body to absorb fluid if your intake is spread throughout the day than if you try to gulp down too much at one time. Beverages to keep you well-hydrated include water (plain or flavored), milk, juice and fruit smoothies. Certain foods can help keep you hydrated such as fruits and vegetables which are high in water content. For better absorption, it’s important that the beverage you choose is cool, as opposed to warm or room temperature. Recent research has shown that low to moderate amounts of caffeine (less than 300 mg) do not cause dehydration or electrolyte imbalance. Drinking a cup of coffee or a few soft drinks is fine, but higher amounts may have a diuretic effect (they make your body lose water). Alcohol has a sustained diuretic effect, so it is not recommended to meet hydration needs.

At least four hours before a triathlon or other endurance activity, drink 1 ounce of fluid for every 10 pounds of body weight (or 5-7mL/kg) to start the event well-hydrated. Don’t experiment with new beverages before or during a competition; stick with the tried and true.

How do I know if I’m dehydrated?

To measure hydration status, check your urine concentration (indicated by color) and volume (amount of urine you make). Your urine should be pale yellow or straw colored. If urine is dark yellow, and there’s not much of it, chances are you’re dehydrated. (Remember that certain vitamin supplements and foods may also change the color of your urine.) A reduction in body weight of at least 2-3 percent of body mass at the end of vigorous exercise represents a loss of body water that needs to be replaced.

What should I drink during exercise?

If you train at a moderate intensity for less than an hour, water is sufficient to maintain normal fluid balance. However, if you’re exercising vigorously, or for longer than an hour, you will benefit from a sports drink. Why? Sports drinks are formulated to provide three important components:

• Fluid to maintain body water balance
• Electrolytes (particularly sodium and potassium) that help the body retain fluid and limit urine output. A good sports drink for exercise lasting longer than two hours should have about 0.5-0.7grams/liter of sodium and 0.8-2grams/liter of potassium.
• Carbohydrates to provide glucose to both the muscles and brain for optimal functioning. Sports drinks are formulated with 6-8 percent carbohydrate to promote fast absorption during activity. During prolonged exercise ingest about 30-60grams/hour of carbohydrates to maintain muscle fuel. This can be in the form of sports drink or snacks.

Every athlete is unique in what his/her ideal rate of fluid intake would be during an endurance event or sport activity. It can depend on many factors such as your sweat rate, gender, size/weight, speed, temperature, metabolism, muscle mass, etc. Fluid recommendations during exercise typically range from 14-27 ounces/hour (0.4 to 0.8 liters/hour), with the lower end of the spectrum applying to smaller and/or slower individuals, and the higher end of the spectrum applying to larger and/or faster individuals. Monitor your thirst and urine output (and weight if possible) to help you adjust the rate of hydration. Ask a sports nutritionist to help you determine exactly how much fluid is right for you.

What about after exercise?



What happens if you drink too much?



