Here’s a news flash for you! You can get dehydrated running in cold weather. So, yes, you need electrolytes running in the winter. But why? And how much?
This past weekend for my long run, I actually planned my hydration. In the winter, hydration is usually an afterthought. The temps were only in the 20s, but I grabbed a couple of Huma +electrolyte gels and water. And lo and behold, my 22 miles (with a 10-mile progression) felt great! I had energy throughout the duration of the run and felt fresh when I completed it.
I truly think taking electrolytes running in the cold made the difference. It was something I wasn’t thinking about up to this point because after all, I haven’t been thirsty on my runs in the cold. And, I haven’t been dripping with sweat as I do in the summer.
But that’s the tricky part about winter hydration. Your body and the weather deceive you. Your body doesn’t give you the thirst cues in the winter as it does in the summer. It almost lies to you!
On top of that, the cold air sucks up your sweat (aka sweat evaporates) so that when you’re done running, you aren’t dripping. This leads you to believe you don’t need to hydrate in the winter.
But do not be fooled. You do!
In this article, I got with Megan Robinson, a registered sports dietitian, to answer the following:
- Can you get dehydrated in the winter?
- 5 reasons you need a winter hydration plan
- Signs of winter dehydration
- Do you need electrolytes running in cold weather?
- Signs of electrolyte imbalance
- Plus a winter hydration guide
So, let’s get moving!
Can you get dehydrated running in the winter?
Yes, you can get dehydrated in the winter, including when running in cold weather.
In fact, there may be an increased risk of becoming dehydrated in the winter because we don’t have the same psychological and physiological cues to drink water. We don’t get thirsty, we are still urinating a lot, and our sweat evaporates, so we don’t see that we are losing fluids.
If you don’t drink the recommended 16-24 ounces of fluid with electrolytes per hour of running, you run the risk of becoming dehydrated.
Specifically, here are 5 reasons why you need a winter hydration plan for your running.
Related: Hydration Tips for Runners
5 Reasons Why You Need to Hydrate in the Winter
Cold air is drier than warm air so your lungs have to actually moisturize the air every time you breathe in.“When we can see our breath on a cold day, that is actually water vapor,” explains Megan. This means you lose water with every breath.
As a whole, cold air is drying—and so is heated air. Whether you’re spending time outdoors, or indoors in heated buildings, your body is fighting against dry air. This is why your skin gts flaky and itchy in the winter. Your body must work harder from the inside and out to get the fluids it needs.
Running in the heat often means running in humidity. There is more moisture in the air and so your sweat evaporates less. But running in the cold, dry air sucks up your sweat quickly so that you can’t tell that you lost a lot of fluids, even though you have.
Sweat evaporates quickly in the cold. Try weighing yourself before and after a long run in the cold. You may be surprised by how much weight you lose from sweating.
Related: Benefits of Running in Hot Weather
Increased sweat rate.
On top of sweat evaporating quickly, you may actually sweat more running in the winter.
“Contrary to what you may think, you lose a significant amount of sweat in cold weather when running longer than 60 minutes,” says Megan. Wearing extra layers and increasing metabolic rates to keep you warm outside contribute to higher sweat rates to help regulate your core body temperature, she explains.
Your blood flow is constricted in the winter, and this can raise your blood pressure. To counteract this, your body tries to rid itself of some of the water in your blood by increasing urine output. This process can lead to dehydration.
And, it can also confuse you because you may think—“hey, I’m peeing a lot, so I must be good.” Pay attention to the color of your urine. It should be a pale yellow. Darker than that is a sign of dehydration.
Another change to our urine is caused by the body redirecting blood from our extremities to our core. Typically, when we sweat a lot, an antidiuretic hormone called AVP signals the body to slow urine production to conserve fluid loss, but this doesn’t happen in the cold because the brain doesn’t detect the blood flow change. Therefore, increased urination can lead to further dehydration.
Related: The 10 Best Supplements for Runners
Thirst is misleading.
Many runners use thirst as a guide when running in hot weather, but your thirst is not a reliable source running in the cold. Studies show that being in the cold can actually reduce your thirst sensations by as much as 40 percent at rest and during moderate-intensity exercise.
This is because of the aforementioned blood vessel constriction, which leads to increased central blood volume and stimulation of central blood receptors. This tricks your body into thinking it is well-hydrated.
Related: Hydration Guide for Runners
How can you tell if you are dehydrated in the winter?
Your body will give you signs that you are dehydrated in the winter such as:
- Slower reaction
- Lack of coordination
- Mental confusion
- Slower reaction time
Do you need electrolytes running in the cold?
Yes, you need electrolytes running in the cold. Most of us remember to get in fluids and sodium when it’s hot. But we can’t take a vacation from our hydration in the winter.
You still sweat when you run in cold weather—possibly more. And in that sweat, you lose electrolytes needed for critical body functions such as:
- nerve signaling
- muscle contractions
- bone health
- pH level balance
- water balance in your body
- the elimination of waste from your cells
- and make sure your nerves, muscles, heart, and brain function correctly.
How many electrolytes do I need to drink running in cold weather?
In an hour of running, the average person loses about:
- 800-1,000 mg of sodium
- 195 mg of potassium
- 20 mg of calcium, and
- 10 mg ofmagnesium per hour
For running in the cold, hydrate with electrolytes about the same as you would running in the heat:
- Aim to drink about 400 mg of sodium to help recover these losses.
- Factors like genetics, weight, and weather will affect how many electrolytes you need, but this is a good starting point.
- Hydration with electrolytes is most crucial for runs over an hour. Runs under an hour require less focus on hydration.
- It’s always helpful to weigh yourself before and after your run to know how much liquid you lose so you know how much to hydrate with. If you lose a two pounds in two hours of running, for example—then you should aim to drink at least 16 ounces in that two hour run time.
When should runners drink electrolytes?
If you are going to run for over an hour, aim to drink a sports drink with electrolytes with you. If you are running for more than 90 minutes, prehydrate with a sports drink and bring an electrolyte drink with you to replenish your electrolytes during your run.
Related: Best Electrolyte Drinks for Runners
What are electrolyte imbalance symptoms?
If you become low on electrolytes, you risk a fluid imbalance in your body leading to a condition called hypovolemia. Just a two percent drop in body weight due to fluid loss can negatively impact performance, and more can be a health risk.
Here are the symptoms of an electrolyte imbalance:
- headaches, and
- fast heart rate
Related: How to Carbo-load for a Marathon
Winter Hydration Tips for Runners
According to Megan, here are hydration tips for running in cold weather. Basically, hydrate as you would if it was hot outside! Bear in mind these winter hydration tips are appropriate for runs longer than an hour.
- Pre-hydrate: consider drinking 16 oz fluid 2 hours before and 8 oz 30 minutes before a long run.
- Have a hydration plan: take small sips (2-3) every mile during long runs even when not thirsty.
- Take electrolytes on your runs: suggest using products with 200-400 mg sodium per hour.
- Drink warm fluids: start runs with warmer liquids to help regulate body temps (this will also help prevent fluids from freezing).
- Limit alcohol: alcohol is dehydrating, so avoid it the night before long runs.
- Monitor your urine: pale yellow urine indicates being well-hydrated. If it’s darker than pale yellow after long runs, drink more fluids.
Hydration in the winter for runs longer than an hour will keep you safe and help you run your best!
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