When you finish a workout, it may feel natural or necessary to reach for the nearest water bottle or sports drink to quench the thirst you worked up. While you know you are thirsty after exercising, you may not know why that cold glass of water sounds so appealing. This knowledge can help you determine how much water you should consume when you have finished an exercise session.
A Look at Thirst
Your body relies on balance to function at its best. This means you must have a balance of fluids, blood, vitamins, mineral, hormones and much more in check at any given time. Your body, especially your kidneys, has sensors that can tell your brain how much fluid you have. If you have excess amounts of fluid, your body signals its release via your urine. Having too little fluid means your brain gets the message you are thirsty. Thirst can be triggered from a number of causes, ranging from eating a spicy meal, loss of blood, or excessive loss of water and salts. The last option is where exercise can come in.
Exercise and Water Losses
When you exercise, your heart rate speeds up and your muscles work faster. These actions create a lot of heat in your body. To cool yourself off, you begin to sweat, which causes water and salts from your body to seep out of your pores. When the water and salts evaporate, the extra air cools you off. While this is a natural reaction, when you finish exercising, the sensors in your kidneys detect you have lost water. As a result, you may begin to feel thirsty.
Losing excess water and salts can upset the blood volume in your body and cause symptoms like mental confusion and dizziness. To prevent this from occurring, it’s important to drink plenty of fluids before, during and after exercise. The American College of Sports Medicine recommends consuming as much fluid as you lost through sweat during your exercise session. To determine how much water you need, weigh yourself before and after your exercise session. For every pound of weight lost, drink between 16 and 24 oz. If you are exercising longer than an hour, you may need a sports drink or other electrolyte-containing beverage to replace lost salts in addition to lost fluids. Taking these steps can help minimize exercise-related thirst.
While thirst after exercise is a normal occurrence, it is possible to experience excessive thirst that indicates the presence of an underlying medical problem. Examples include diabetes, a psychological disorder or diabetes insipidus, an imbalance of hormones that causes you to feel constantly thirsty. If your thirst is accompanied by unusual symptoms like blurry vision or fatigue, these can be signs you have an underlying condition and should seek medical attention.
- MedlinePlus; Thirst -- Excessive; January 2011
- "Nutrition: Science and Applications"; Water Loss and Exercise; Smolin/Grosvenor
- American College of Sports Medicine; Exercise and Fluid Replacement; Victor Convertino, Ph.D.; January 1996
- Go Ask Alice!; Best Thing to Drink Before a Workout? After?; September 2008