It’s July and here in Texas it’s ridiculously hot — like stepping into an oven hot. Makeup melting off your face in 2.3 seconds flat hot. Why even bother with deodorant hot. But without a gym membership for running, walking, and lifting, I’ve had to pay special attention to my hydration strategy during these sweltering months.
One thing to note is that women and men experience dehydration and thirst differently. Estrogen and progesterone affect the hypothalamus (the part of the brain that regulates fatigue and fluid balance hormones). Fluctuating hormone levels affect thirst, the ability for the body to hold on to fluid instead of just peeing it out, and how the body responds to dehydration.
Also, women’s core temperature tends to get hotter than men’s during exercise, and our sweat rates can vary depending on where we are in our cycle and if we’re perimenopausal/menopausal or not.
As we get older, our thirst becomes a less reliable indicator of hydration levels and we become less tolerant of the heat. Low estrogen can hinder our normal cooling response, as well as thirst and sweat rate.
Women are more prone to hyponatremia, which is a dangerous condition when the level of sodium in the blood is too low. This makes *what* we drink as important as how much.
We need to be extra aware of our hydration needs when it’s hot. A tough workout on a hot day can make us feel a bit sick as opposed to thirsty, lessening our desire for food and water, exacerbating our dehydrated state.
General guidelines for hydration per Dr. Stacy Sims, female exercise physiologist and nutrition scientist:
0.12 oz per lb. of body weight (17 oz for a 140 lb. woman) in 75-degree temps or lower
0.16 oz per lb. of body weight (22 oz for a 140 lb. woman) in 80-degree temps or higher
Dr. Sims recommends a hydration drink containing:
3-4% carb solution (7-9.4 grams carb from glucose & sucrose per 8 oz water)
180-225 mg sodium
60-75 mg potassium
There aren’t a lot of premade sports drinks that fit this bill, unfortunately. The few that do include Osmo Nutrition Active Hydration for Women (which I have started drinking recently and like) and Infinit Isis Endurance (they do custom blends!). BioSteel is a good low-calorie option (add some kind of carb source for intense and/or long workouts).