Hydration in the Heat
It’s officially summer and the weather has been HOT, HOT, HOT! And that means more sweating, and fluid loss. Did you know that even mild dehydration means a deficit of 1 - 2 percent of your total body fluid?
That’s only 1 ½ - 3 pounds for a 150-pound person. Total body water comprises approximately 45 - 75% of a person’s body weight. Muscle mass is 70 - 75% water, while water in fat tissue can vary between 10 and 40%.
Water functions in the body to:
- Regulate body temperature
- Lubricate joints and organs
- Provide structure to cells
- Transport vitamins, minerals and nutrients through the body
- Preserve heart function (such as maintain a lower heart rate) In this hot weather,
if we’re not rehydrating adequately it is really easy to become dehydrated.
Our bodies are Amazing!
Maintaining constant water and mineral balance requires the coordination of sensitive detectors in our bodies. These detectors are precise; when there is a lack of water, fluid is pulled out of cells (intracellular) and pushed into the bloodstream (extracellular), causing the cells to shrink. Signals are then sent to our brain to tell us to hydrate, and hormones cause a decrease in urine output (helping us hold on to our water stores). This means, THIRST is a poor indicator of hydration. Because if you’re thirsty, your body is already adjusting to conserve its’ precious resource!
Signs of mild dehydration include:
- Moodiness (mood aspects particularly affect women, like issues such as happiness, fatigue & confusion)
- Decreased physical performance and slower reaction time
It’s worth noting that most studies on hydration and cognitive performance are short-term (i.e., hours, days) and it is not certain if there are longer-term cognitive declines resulting from dehydration.
Stay hydrated this summer!
A great way to tell if you’re adequately hydrated…look at your urine (that’s right, check out your pee). It should be mostly clear, with a tinge of yellow, anything darker and you’re dehydrated. An exception to this rule is if you’ve recently taken a multivitamin (which naturally turns your urine a bit of a neon yellow).
For those of you who are more methodical and would prefer a numerical target. You should aim to drink half of your body weight in ounces. For example, a 150-pound person would drink about 75 ounces per day. Adjust this number according to your activity level. The more active you are, and the heavier you sweat, the more you should drink. If you were to weigh yourself before exercise and post exercise, you would replete your body with 16 ounces for every 1-pound loss. For example, if you weighed 150 pounds pre-exercise, and 149 pounds post-exercise, you should consume 2 cups of water to reach euhydration (hydration homeostasis).
Tips to staying hydrated:
- Drink water! Our bodies are made of water, not soda, or juice.
- Although these beverages will help hydrate; in reference to soda they may cause an increased loss of calcium (which is concerning for both bones and kidneys). And the juice adds unnecessary sugar!
- Flavor your water; try lemon or lime juice, mint leaves, lemon balm, cucumber or berries.
- I do not recommend using commercial flavor enhancers as many use sugar substitutes like artificial sweeteners and sugar alcohols that studies show disrupt the microbiome (our healthy gut bacteria).
- Find what fits you: some people drink more when they have a straw, others less, some prefer ice water, others room temperate.
- Carry a glass or stainless-steel water bottle (if you need to, create challenges for yourself to consume “x” amount by 12, 4 and 8 pm, for example).
- Eat fruits and veggies! Fruits in particular are water dense; foods such as watermelon, grapes, lettuce and cucumber can offer some of your fluid needs.
- Drink smoothies, eat popsicles and enjoy frozen fruit as a refreshing summer snack!