Hydration for Older Adults
By: Brad Hankins
What better month than July to explore hydration. The most common hydration question I am asked is how much fluid should I drink? The answer is it depends – on a lot of things. A basic rule of thumb https://www.ncoa.org/article/how-to-stay-hydrated-for-better-health/ is to divide your body weight by 1/3 and that will be the minimum number of ounces of fluid you should drink in a twenty-four-hour period. For me that is 68 ounces, 8.5 cups or a little over 2 liters per day. At age 51 and above The National Academy of Medicine recommends 13 cups (3 liters) of fluid per day for men and 9 cups (2.25 liters) for women every 24 hours. Again, these are minimum recommendations for a normally health older adult.
Please notice I am using the term “fluid” and not limiting fluid to just water. Most liquids and some foods count https://health.clevelandclinic.org/drink-up-dehydration-is-an-often-overlooked-health-risk-for-seniors toward your daily intake. The outliers are alcohol and high levels of caffeine which are diuretics and reduce fluid volume in the body. So, juice, milk, coffee (in moderation), soup and even popsicles count (keep an eye on sugars if you are diabetic or have other metabolic conditions). Foods such as cucumbers, tomatoes, apples, bell peppers, watermelon and celery are also high in fluids. And, both meat and fish are high in fluids as well. I get quizzical looks when adding meat to the fluid list but consider marine mammals such as seals cannot drink sea water and get their fluids through fish and other marine life they eat.
Having a few miles on the odometer means we can become dehydrated easier than in our 20’s and 30’s. There are many reasons for this, with a decline in total body fluid being toward the top of the list. If you recall from previous posts, our muscles are our water tank and as muscle mass declines with age our ability to store water literally shrinks. More muscle equals more stored water which equals more fluid reserves when challenged by heat, exertion, injury or acute health conditions – especially those resulting in vomiting and diarrhea. Yes, you need to lift weights.
Another age-related dehydration issue https://www.healthline.com/health/symptoms-of-dehydration-in-elderly is decreased thirst response. Simply put, with age we become more dehydrated before feeling thirsty. This is because our thirst center, located in our brain’s hypothalamus, becomes less responsive as we age. In turn this makes it important to drink/eat fluids over the course of the day – don’t wait until you are thirsty. We can balance our hydration level by being aware of the need for morning and mid-day drinks and taking in more fluids with meals and snacks. A suggestion is as soon as you are out of bed, before coffee or food, drink one or two cups of plain water. This is because as we sleep our brain dehydrates through our breathing, and as our brain is very fluid dependent the extra water first thing in the morning gives it a boost. Also consider a cup or two of water with your second cup of coffee in the morning and with your tea or soda in the afternoon.
Early signs of dehydration need to be responded to quickly by resting and drinking more water. These signs include dry or sticky mouth, dark yellow urine, decreased urination, headache, muscle cramps, dizziness and fatigue. Be especially aware of these symptoms during hot and/or humid weather and increase your fluid intake as temperatures and humidity rises to help prevent the symptoms from occurring.
When exercising, the best hydration plan is to be fully hydrated before stepping into the gym. This means drinking 15-20 ounces (2 to 2.5 cups or a half liter) of fluid in the hour prior to exercise. During exercise 10 ounces (approx. 1 cup) of fluid for every 20 minutes of exercise. And after exercise slowly drinking a liter (approx. 4 cups) of fluid with a fibrous snack such as a banana (to slow water absorption), will ensure you are fully rehydrated and ready for the day.
Sports drinks, or electrolyte replacements, are usually not necessary when exercising for an hour or less – water works exceptionally well https://extension.unh.edu/blog/2023/09/hydration-are-electrolyte-drinks-better-water . However, sports drinks do have a place such as after strenuous exercise in warm weather, e.g. 10k run or a day of summer mountain hiking. They are also beneficial during an illness when experiencing prolonged sweating, diarrhea or vomiting. People with hypertension need to be aware of the high levels of sodium and potassium in these drinks which can increase blood pressure. Electrolyte drinks are not meant to be consumed throughout the day as if they are water but do have their place in certain circumstances.
In summary:
- Rehydrate early each day and remind yourself to stay hydrated over the course of day (at least 2-3 liters over 24 hours).
- Ensure you are hydrated before exercise (1/2 liter), hydrate during exercise (1/2 to 1 liter) and slowly rehydrate after exercise (1 liter ).
- Be aware of the early signs of dehydration and respond quickly with additional fluids and rest as they appear.
I would enjoy hearing about your fitness journey, please feel free to email me at hankinsb@ssymca.net.
Brad Hankins RN, CPT
