There’s nothing more refreshing than gulping down water—and then splashing it all over our red faces—during a hot and humid run in the summer. Having water on hand is a must to prevent dehydration. But what about during those winter workouts? Is it still possible to be at risk for dehydration?

Winter dehydration is real.

Cold Weather Dehydration: The Causes

There are a few reasons why dehydration can occur during winter runs or other outdoor workouts.

In the heat, we are more likely to drink water. But in the winter we often don’t feel thirsty. In the cold weather, the thirst response can decrease up to 40 percent as the blood vessels constrict to conserve heat. The body then is tricked into thinking it is hydrated.

This means we don’t have that thirst cue to remind us to hydrate.

But just because we aren’t thirsty doesn’t mean we shouldn’t be drinking water in the winter weather.

Another reason why there is a risk for dehydration is that sweat evaporates quickly in the cold. This means we think we aren’t sweating as much so that means we aren’t losing a lot of fluids.

This isn’t the case.

We also often work up a good sweat because those base layers and layers upon layers increase body temperature. Then we start the workout, so expect to still be sweating even though we don’t feel it as much.

Then there is the fact that the body uses more energy to move outdoors in the cold, while also working harder to keep warm.

Plus we lose fluids via the cloud of breath we see out in the cold. That cloud is moistures getting the cold air. The colder the temperature and more intense the workout, the more vapor is released.

Then there is the urge to use the bathroom that always hits during winter runs. This is called cold-induced diuresis, a very real condition. Frequent urination further adds to dehydration in cold.

Signs Of Dehydration

One of the clearest signs of dehydration is not having clear urine. The darker the urine the more dehydrated the runner is. Urine should be a light yellow color.

Signs of dehydration include dizziness, fatigue, headaches, very dry skin, increased heartbeat, and rapid breathing.

Dehydration can cause cramps—which can really affect performance when working out—along with a lack of coordination.

Prevention

When a runner is as little as two perfect dehydrated, performance can be negatively affected. This is why staying on top of fluid intake is important.

Drinking eight glasses of water a day is easy to remember, but it’s recommended to drink half an ounce to an ounce of your body weight. So if you weight 150 pounds, aims to drink at least 75 ounces of water daily.

Drink water before, during, and after the workout. This means wearing a hydration belt or vest for long runs or bringing a water bottle to that outdoor workout.

Avoid drinking too much coffee since caffeine is a diuretic, but a cup is fine and just make sure to continue to hydrate.

Eating fruits and vegetables is important for nutrition purposes, but it also aids in hydration. Watermelon, grapefruit, cucumber, celery, broccoli, green cabbage, spinach, eggplant, and zucchini are all options high in water content.

Even hot liquids count such as soup and hot tea. Warm liquids also help regular body temperature after a cold winter workout.

Sources:

8 Tips for Hydrating in Cold Weather, Felicia D. Stroler, Health
Kenefick RW, Hazzard MP, Mahood NV, and Castellani JW. Thirst sensations and AVP responses at restand during exercise-cold
exposure. Med Sci and Sports Exerc. 1528-1534 (2004).

Water and Your Diet: Staying Slim and Regular with H20, Gina Shaw, WebMD

Your Risk of Dehydration Increases in Winter, Dr. Thomas Bell, Performance Health Center