Fitness Facts: The heat is on … hydrate!
By Dr. Maggie Sabay
Nurse Practitioner, Canyon Health and Wellness Clinic
The Phoenix heat is here. We are always reminded to use sunscreen, but now let’s talk about hydration.
Dehydration is defined as a reduction in total body water below the normal level without a proportional reduction in sodium and potassium, resulting in a rise in sodium concentration in the blood.
Now, what’s thirst and what causes thirst? Thirst is a signal that lets us know we are lacking fluids or there is an increased concentration of certain osmolytes (substances) in our body, such as sodium.
Water within our bodies moves from a low concentration gradient to a higher concentration gradient. When you eat foods that contain high levels of sodium or when you drink any concentrated drinks (even soda), they tend to worsen dehydration because the high concentration level in your gut pulls water from your cells.
When the water volume of the body falls below a certain threshold or when the concentration of it becomes too high, your brain will sense changes in blood constituents and signal thirst. By the time you feel thirsty, your total body water is quite low.
Although increased thirst at times may be related to medical conditions such as diabetes mellitus, diabetes insipidus, psychogenic polydipsia, hypernatremia, etc., thirst may just be the result of decreased water volume.
Increase your water intake. Always drink enough water. Do not wait until you feel thirsty. Coffee, soda, tea or alcohol are not dehydrants. The combination of these drinks and water can work against your body and cause dehydration.
So how much water should we drink per day? Here’s what the Mayo Clinic recommends:
“The U.S. National Academies of Sciences, Engineering and Medicine determined that an adequate daily fluid intake is about 15.5 cups (3.7 liters) of fluids a day for men and about 11.5 cups (2.7 liters) of fluids a day for women.”