Adequate hydration is imperative when you’re physically active. Otherwise, you’re at risk for dehydration, the inability to replace lost fluid needed for normal body functioning. Dehydration not only impairs athletic performance, especially in a hot environment, but it can be life threatening if not properly managed.
Signs of Dehydration
- Difficulty concentrating
Both beginner and serious athletes should monitor the body fluid they lose. While small amounts are lost through functions like breathing, urination, and defecation, sweat-loss during exercise and sports is the most common cause of dehydration. Sweating varies widely depending on the individual, environment, clothing and equipment used. So keep an eye on fluid loss with these easy tips:
- Weigh yourself on a scale before and after athletic activity to measure sweat loss.
- Consume 16 ounces of fluid for each pound of sweat lost.
- Avoid losing greater than 2 percent body weight from fluid loss.
- Keep an eye on urine color. It should be pale in color. Dark urine may be a sign of dehydration.
Electrolytes like sodium, potassium and chloride, important for proper hydration, are also lost when sweating. Salt/sodium is the primary electrolyte lost and may range from 200 to 1,500 milligrams for every 2 pounds of sweat lost.
While other electrolytes are important and can be lost in sweat, they are lost in small amounts and typically do not require replacement during training.
For maximum benefit during training and competition, it’s best to consume fluids in small amounts every 10 to 20 minutes. Depending on whether or not you need electrolyte replacement, it’s easy to consume fluid by drinking water and sports drinks.
Water is a calorie and electrolyte-free form of fluid replacement, best consumed by itself for shorter duration, or less intense competitions such as a 5K run. For longer duration, higher intensity events, or when exercising in extreme heat, you may need to combine water with other energy and electrolyte sources.
Sports drinks provide a combination of fluid, electrolytes and carbohydrates. The sodium provided in sports drinks, assists in fluid absorption while also replacing sodium lost through sweat. Sports drinks are also helpful as they may promote drinking of additional fluids due to their sodium content and flavor profile.
A Cautionary Note
Watching fluid intake and loss is also important because drinking too much fluid can lead to a potentially dangerous condition called hyponatremia. Symptoms of this condition are similar to dehydration: confusion, fatigue, nausea and vomiting. The key difference is that hyponatremia will likely lead to weight gain, not weight loss. If you experience any of these symptoms with weight gain, you should reduce your fluid intake.