Ask any fitness expert to list a couple of common workout roadblocks, and dehydration will likely always make the cut. It’s a killer! You need water to exercise—you thrive on it—yet so many women spend their days dehydrated. So, what gives? It could be because, when it comes down to it, you may not even know exactly when you’re dehydrated. To solve that problem, we asked Greg Justice, an exercise physiologist at AYC Fitness in Kansas City and author of Mind Your Own Fitness, to list the top signs you need to get way more H20 happy:
You Have a Headache
Unless you’re chugging water 24/7, your body is constantly losing fluid. That means you’re also losing essential salts like sodium and potassium because those are in the fluids you’re losing. Now get this: That salt loss actually changes the chemical makeup of your blood. Your brain, in turn, is super sensitive to that change—and it’s that sensitivity that triggers a headache. Make sense? The headaches get even worse, too, depending on how much water you lose. “The more water you lose, the more your blood volume drops, which causes less oxygen flow to the brain,” says Justice. “That causes your blood vessels to dilate, which can make your headache feel even worse.” Moral of the story: Not enough water equals headache central.