Importance of Hydration
September is the time of year when the weather begins to cool down and summer comes to an end. However, warmer weather may still be around for a couple of months, and with that comes an important consideration: staying hydrated.
Dehydration can occur by losing too much fluid (usually through sweating) or by not drinking enough fluid. You may recall from school that the human body is made up of approximately 70% water, so this fact alone illustrates how important this nutrient is for us!
The body has mechanisms in place to urge us to drink fluids, most notably the feeling of thirst. However, by the time you feel thirsty, you are actually already experiencing mild dehydration.
There are many other symptoms that can signal dehydration. According to Medline Plus, they include the following: thirst; dry mouth; decreased urination; dry, cool skin; headache; darker yellow urine; muscle cramps; dizziness; rapid heartbeat and/or rapid breathing.
Keeping an eye out for these signs are important for everyone, but they are particularly critical for two groups: older adults and athletes.
Older adults have a decreased response to thirst and are more likely to be on a diuretic. These factors make it important for this population to drink fluids constantly throughout the day, even when they may not feel thirsty. This is especially important during prolonged exposure to heat during physical activity, such as walking, gardening, mowing the lawn, etc.
Athletes exercising in the heat can lose an average of 2.0 L of water through sweat per hour! Not replacing the lost water can cause serious fluid imbalances and dangerous rises in core temperatures. Unfortunately, student athletes are often the victims of poor monitoring of hydration status. According to sports nutrition experts William McCardle and Frank and Victor Katch, "Hyperthermia (dangerously high body temperatures) has occurred more than 100 times over the past 30 years among football players who died from excessive heat stress during practice or competition." These situations are completely preventable by making sure to either have water or an electrolyte replacement beverage at all times during outdoor activity in the heat.
If dehydration does occur for any reason, there are several steps that can be taken:
- Sip water or suck on ice cubes (or an electrolyte sports drink)
- If heat exhaustion is also a problem, lie down somewhere cool and focus on breathing slowly
- For severe situations, go to a hospital immediately
Notice that the first suggestion is to sip water. Rehydrate slowly if you become dehydrated!
How much fluid should you be drinking? A good rule of thumb is 2 cups of water 20 minutes before being active in the heat. For athletes or anyone engaging in vigorous exercise, you can weigh yourself before and after activity takes place to gauge how much fluid you need to take in to replace losses. For example: If 2 lbs., or 32 oz., is lost during an hour of activity, 32 oz. (or 4 cups) of water or a sports drink should be ingested over the next hour. In terms of choosing between water and a sports drink, always choose the sports drink if activity is lasting longer than an hour. Below an hour, water is usually sufficient.
So whenever you leave the house, always bring a water bottle with you! Dehydration is 100% preventable, as long as you provide your body with the fluids it needs every day.
- McArdle W, Katch FI, Katch VL (2013). Exercise, Thermoregulation, Fluid Balance, and Rehydration (4th ed.). Sports and Exercise Nutrition (pg. 319-335). Baltimore, MD: Lippincott Williams and Wilkins.
- Popkin B, D'Anci KE, Rosenberg IH (2010). Water, Hydration, and Health. Nutrition Review; 68 (8): 439-458.
- U.S. National Library of Medicine (2013). Dehydration.
Prepared by Nicole Hindle, Dietetic Intern at Cedar Crest College, Allentown, PA.