Food & Fitness After 50: Beat the heat hydration tips

This post was written by Dr. Bob Murray, co-author of Food & Fitness After 50, and hydration and exercise expert.

satchel-paige-angie-villegasFamed baseball player Satchel Paige’s career spanned from 1924 to 1966, incredible longevity for any athlete.  In addition to being an amazing pitcher, Satchel’s unique perspective on life produced many memorable quotes, including “Age is a question of mind over matter.  If you don’t mind, it don’t  matter.”  Also, “How old would you be if you didn’t know how old you were?”  Both quotes speak to the importance of maintaining an optimistic, positive attitude about aging, although our bodies naturally change as we age.  Some of those changes influence our ability to stay well hydrated, especially so during the hot summer weather.

What does staying hydrated mean?

It is important to point out that staying hydrated—drinking enough each day to prevent significant dehydration and its consequences—is usually not a problem for the vast majority of older adults.  Although it is true that our thirst mechanism becomes less sensitive as we age, that change does not typically increase the risk of dehydration.  That may sound counterintuitive but it turns out that humans of any age do not rely solely on thirst as the primary gauge for when to drink.

Drinking at meals accounts for most of our daily fluid intake, along with the spontaneous drinking that occurs throughout the day—stopping at the water fountain and drinking coffee, tea, bottled water, and soft drinks at work or while watching TV are examples of spontaneous drinking.  The fact is that thirst plays a minor role in our daily fluid intake and that is especially true for those older adults who are inactive.  For those reasons, the reduced thirst sensitivity that occurs as we age does not have a major influence on our day-to-day hydration.  However, as with all things in life, there are exceptions.water

The dangers of dehydration

When older adults fall ill, suffer immobilizing injuries, or fight diseases, the loss of thirst sensitivity can contribute to dehydration because normal drinking at meals and spontaneously throughout the day is completely disrupted.  Age-related loss of thirst sensitivity can also be a problem during heat waves or with prolonged sweating during endurance exercise, long hikes, and yard work when sweating results in dehydration.

Periodic heat waves cause a disproportionate number of deaths among adults over age 50, deaths that occur mostly from heart failure, not from heat stroke.  Prolonged exposure to the heat creates enormous strain on the heart and blood vessels to deliver much more blood to the skin to aid in heat loss. Dehydration makes matters worse because the sweating and inadequate drinking that lead to dehydration reduce the total volume of blood, placing even greater strain on the heart.  For those with preexisting heart, lung, or kidney disease, that strain can simply be too much to handle, resulting in death.  Older adults who are ill, out of shape, lack air conditioning, and have limited access to fluids are at greatest risk during heat waves.

         On June 8, 1982, Leroy “Satchel” Paige died of heart failure and emphysema at age 75.  Satchel’s death occurred after a power failure at his home in Kansas City.  Although there was no heat wave at that time in Kansas City, the maximum temperature that day was 86 and the maximum relative humidity was 93%, a combination that would make it feel like 108.

Aging not only reduces our thirst sensitivity and prolongs the time it takes us to fully rehydrate after we become dehydrated as a result of physical activity or heat exposure, we also sweat less, our heart’s capacity to pump blood is less, we deliver less blood to the skin, and we are less able to divert blood from our internal organs into the main circulation, all of which makes it tougher to cope with the heat.

How to win at hydration

While that may sound like uniformly bad news, we can avoid the dire consequences by staying physically fit, acclimating to the heat, and reminding ourselves of the importance of drinking more, particularly whenever we sweat.  Getting outdoors in warm weather may initially feel uncomfortable, but our bodies will gradually acclimate over time.  That acclimation improves our sweating and our hydration because acclimation prompts us to drink more throughout the day.

Additional good news is that for maintaining hydration, virtually all fluids count.  Okay, that advice does not include shots of tequila or other liquors, but mixed drinks do count toward daily hydration, as do coffee, tea, colas, energy drinks, beer, and wine.  As with food, consuming a wide variety of fluids during the day is important for overall nutrition and for hydration, both of which are vital for good health. Summer fruits and veggies are high in water content, so snacking on grapes, watermelon, cantaloupe, berries, summer squash, tomatoes, and cucumbers deliver both water and nutrients.

For more on the importance of hydration and a guide to finding your individual hydration needs, see Dr. Murray’s chapter on hydration in Food & Fitness After 50.

 

 

Hydration Tips for Active Older Adults

As the temperatures soar, active 50+ exercisers (myself included!) need to pay special attention to hydration. There are some who say that thirst should be your only guide for hydration, but that advice could be dangerous as we age. When older adults exercise, especially in hot and humid climates, they have a diminished sensation of thirst. And we know that “normal” thirst kicks in after you are already thirsty so waiting for thirst may lead to heat illnesses.

Aging also brings about other changes in normal physiology that contribute to dehydration. Our sweat rate changes, our kidneys change the way they handle fluids and electrolytes, like sodium and potassium, and there is an altered blood flow response. All of these normal age changes mean that we need to be aware of hydration and adopt strategies to keep us hydrated during the physiological stress of exercise.

In addition, many 50+ take medications that contribute to loss of body water. Chief among the drugs are common blood pressure medications that act as diuretics which can increase water loss. When you add in other common drugs, caffeine and alcohol, both which are mild diuretics, hydration becomes even more important.

How do you know if you are dehydrated? This question is of great interest to researchers and unfortunately there is no single, easy test to assess hydration. Until there is an easy reliable and valid test, the best strategy is to weigh yourself before and after exercise. For every pound loss, drink 16-24 ounces for every pound loss during exercise. If you gain weight after exercise that means you are most likely overhydrated, but a loss of 1 pound or less means you are doing pretty well at hydrating. Another way to assess hydration is by monitoring urine volume and color. A dark colored urine usually means you are dehydrated (although some dietary supplements like vitamins with a high concentration of riboflavin can cause a bright colored urine) as well as infrequent urination.

Here are some tips to keep you hydrated:

  • Monitor body weight before and after exercise to gauge fluid loss
  • Monitor urine volume and color
  • Drink fluids before activity and during activity when exercising in hot, humid environments
  • Replace fluids after exercise
  • Eat foods with high water content (fruits and vegetables)
  • Consume fluids with meal
  • Use sport drinks if you are a heavy sweater and/or a salty sweater; if watching calories, try the “light” verisons that provide some carbohydrate but with the same electrolyte content as the regular sport drinks.

Coconut Water, Homemade Sports Drinks and Other Thoughts on Hydration

As college students make their way to campus, college athletes are taking the field and hitting the gym for sports training and competition. Two questions that I’m being asked are, “is coconut water better than sports drinks?” and “should I make my own sports drink to cut down on sugar?”

First, coconut water…although being marketed as “super-hydrating,” it isn’t better than sports drinks and for some athletes sports drinks still have the greater advantage. Coconut water is the liquid inside green coconuts and it not the same thing as coconut milk (which is made from pressing coconut meat). In a few studies coconut water has been shown to be an effective rehydration beverage compared to water but isn’t superior to sports drinks.

Here are the pros and cons of coconut water:

Pros

  • Similar in calories to sports drinks (46 calories vs. 50 calories per cup)
  • Slightly lower in sugar than sports drinks (about 2 teaspoons vs. 3 teaspoons of sugar per cup)
  • Contains some protein (about 2 grams per cup)
  • High in potassium…about the same as found in a large banana

Cons

  • Lower in sodium than most sports drinks and sodium is needed by athletes who sweat heavily and are “salty” sweaters
  • Can have a mild laxative effect when large amounts are consumed
  • Expensive…$1.75 to $2.50 per serving
  • Not all brands passed the Consumer Labs test to make sure that what is in the bottle is the same as what is stated on the label

Don’t be fooled by the claims of high potassium in coconut water….although it is a good source of potassium, athletes lose about ten times more sodium in sweat than potassium, so athletes need the sodium found in sports drinks.

And, what about the homemade sports drinks? First, carbohydrate in sports drinks is a good thing…the 14 or so grams of carbohydrate per cup help to replace muscle glycogen (carbohydrate) and makes the drink palatable. I’ve never been a big fan of homemade sports drinks because of the quality control….when you buy a bottle of Gatorade or PowerAde you know what you are getting. When you make your own sports drink and the recipe calls for a “pinch” of salt, how much sodium are you really getting? And, research shows that a beverage that tastes good will lead to greater consumption…and I’ve yet to taste a “homemade” brew that tastes good. I encourage athletes to stick to the tried and true sports drinks when exercising at high intensity, for long duration, or during hot and humid practices (think football, soccer, tennis, or cross country practice in August).

Enjoy coconut water if you want a light tasting refreshing drink (and can afford it), but athletes will still get great benefits from drinking sports drinks.