The Importance of Water in Your Diet
Water is our most essential nutrient. We can live longer without food than we can without water. Water makes up 60 percent of our body weight (blood is 90 percent water). Lost fluids need to be replaced during the day to maintain body temperature and energy.
Our bodies keep cool during exercise by circulating blood to the skin, where water is lost in sweat. If you lose too much water, you dehydrate. In extreme cases, dehydration can lead to heart failure and even death.
What Can Happen When You Don’t Drink Enough Water
Most active people have experienced mild dehydration without knowing it. This is because the signs of mild dehydration can be subtle. To improve dehydration, tune in to your body’s warning signals:
- Loss of energy
- Loss of appetite
- Flushed skin
- Sensitivity to heat
- Small amount of dark yellow urine
What You Need
- Most adults need about two quarts of fluids per day to replace normal water loss.
- If you’re very active—marathon training or playing tennis every day—you will need more.
- To evaluate your fluid needs, weigh yourself before and after each workout. Every pound you lose equals approximately two cups of fluid.
- Drink enough fluids to make up for any weight loss, plus your normal daily requirement of two quarts.
Exercising in the Heat
When you exercise outside on hot days, it’s important to pay attention to your fluid needs to avoid dehydration or heat illnesses.
It’s best to avoid exercising in the heat. If you do exert yourself on hot days, whether working out or mowing the lawn, stay safe and follow these guidelines:
- Before exercising or strenuous physical activity, drink one to two cups of fluid.
- During activity, drink four to six ounces of water every 15 to 20 minutes.
- After exercise, drink plenty of fluids right away, even if you aren’t thirsty (thirst is a poor indicator of fluid needs).
- If your activity was particularly intense, you should increase that amount by one or two cups.