Do you exercise outside in cold weather? If so, then you should ask yourself, are my hydration needs being met in the winter? Because when you exercise outside in the winter, although your sweat is less noticeable and your thirst sensation can decrease by 40%, you still lose water all day long through evaporation and aspiration.

This is why you can see your breath in cold weather – it’s the moisture in your breath hitting the cold air. This doesn’t happen in warm weather because warm air holds more moisture. For the same reason, the recirculated heated air inside your home in winter is typically drier than when the heat is turned off in warmer weather – hence the “cotton mouth” when you wake up. It’s the cold, dry air and some level of dehydration that makes your lips crack and gives you that scaly and itchy skin, too.

Cold weather can also change what’s going on inside your body.  Do you ever notice that you have the sensation of needing to urinate more often in the cold weather? This sensation even has a name – it’s called cold-induced diuresis. The vasoconstriction that occurs in your blood vessels to keep your blood closer to the inside of your body so less heat escapes through your skin contributes to this sensation.

In addition, your metabolic system revs up to help keep you warm. Getting the “chills” or “goosebumps” is your body’s way of both vasoconstricting and burning energy to keep you warm. But one of the byproducts is more water lost through urination, which can further contribute to dehydration. 

Cold weather contributes to dehydration in several ways:

  • Increased urine production and urination
  • Increased metabolic rate leads to greater respiratory water loss
  • Sweating brought on by wearing heavier clothing and the accompanying dampness
  • Greater expenditure of energy for movement outdoors
  • Reduced sensation of thirst

What about cold weather clothing?

Cold weather clothing also contributes – if you aren’t wearing the right kind. Wearing extra layers causes your body to work harder to do the same thing because the clothes are heavier and they inhibit movement. When these clothes get even slightly damp from sweat, your body has to work harder to stay warm. So try to wear wool against your skin and then a layer of goose down. If needed, put a water and/or wind resistant layer on top. This combination will allow your skin to “breathe” but still keep you warm.

How does cold weather dehydration affect performance?

You can experience different physiological effects to your performance when you become dehydrated in cold weather. An athlete can experience decreases in blood volume, skin blood flow, and sweat rate/heat dissipation, as well as an increase in core body temperature and greater use of muscle glycogen.

Exercise ability can be hindered with as little as 2% body weight dehydration; and much research has been conducted on athletes who experience up to 5% dehydration, which can decrease work capacity (the amount of work the body can do) by as much as 30%. And for rapid and high intensity movements, as little as 2.5% dehydration can decrease high-intensity exercise by up to 45%.

Because of the nature of their movements, these athletes typically don’t lose much water while exercising, but it’s still important to start hydrated and stay hydrated. Even low-intensity exercise (like walking or working outside) can be affected with 3% or more dehydration. For a more in-depth explanation on how cold weather affects physical performance, I recommend this review.

What’s the best cold-weather hydration strategy?

So what should you drink? Cold beverages feel good in the summer and will hydrate quickly; but in the winter, a warm or room temperature beverage is better for keeping your internal temperature regulated. So keep making your Catalyte mixture in your insulated bottle during the winter months. You might need to replace close to 150% of the sweat you lost during an outside workout to compensate for the weather.

Use a Thorne shaker bottle with a measuring amount on the side to show how much you have consumed. Soup, broth, tea, or fruit- or vegetable-infused water are also good options to keep you drinking more. And despite what you think about drinking alcohol to stay warm, alcohol actually has the opposite effect. Alcohol is a vasodilator and contributes to the loss of body heat through your skin, which causes a drinker’s well-known “red cheeks.”

How do I know if I’m hydrated? 

As you age, you are more likely to become chronically dehydrated. We have a few quick things you can do to check your hydration status. First, monitor your urine color (the stream, not what’s in the bowl). Compare that to a urine color chart and keep track of how much you’re drinking and what color your urine is. The darker the color, the more dehydrated you most likely are, so try to maintain a light-yellow color – think lemonade not apple juice or tea.

Second, take a mental note of your urine volume. Have you urinated a few times today or only once? Does it seem like what you drank is what you urinated out? If your volume is low, then your body is holding onto fluids, which could be because you’re dehydrated or because of dietary factors like eating salty foods.

Third, weigh yourself regularly and at the same time of day – first thing in the morning, for example. This will help you monitor whether you are retaining water or slightly dehydrated. Do the same thing pre- and post-exercise – a quick check of body weight provides insight into how much you sweat and how much fluid you need to replace. For every pound of weight you lose during cold weather, try to consume 16-24 ounces to replace it.

Tips to guide you: 

  • In cold weather, drink as much or more than you would in warm weather; you might not know you’re thirsty, but your body does.
  • Room temperature or warm beverages will help keep you warm – but avoid alcohol.
  • Insulate your Catalyte in an insulated bottle.
  • Insulate your body with appropriate winter clothing.
  • Monitor your hydration status and adjust your fluid intake to meet your needs.