Runners don’t think as much about hydration during the winter. There are, for instance, fewer acute indicators (“I am so thirsty!”) urging one to drink during this season. Winter hydration is trickier than it might appear, though, so it’s important to to have a season-specific hydration plan.
It should go without saying that drinking adequate amounts of water is a Good Thing. Beyond the ordinary advantages to runner health that it confers, water is particularly good for you during the wintertime because it can give your immune system a boost during cold and flu season. However, winter running has its own set of considerations regarding hydration that makes determining “how much is enough” a little complicated.
If the air is very dry, your lungs actually need to work harder to humidify cold, dry air. This problem is further exacerbated at higher altitudes. If your body is working harder, you need to drink more. We can also be fooled into thinking that we’re not sweating because it’s cold outside –– that’s just not true. The body’s sweat rate doesn’t actually change because of a drop in temperature. Sweat rate is largely independent of weather conditions and is largely determined by fitness level and pace. It might feel like you aren’t sweating as much in cold weather because moisture more quickly evaporates, but you are still losing the same amount of fluids on a cold day as you are on a hot one. Therefore, if you aren’t drinking enough during cold-weather runs, you are probably at risk from cumulative dehydration.
You might not be overheating in these conditions, but you are still losing fluids
General wisdom about hydration amounts still applies during the winter. Athletes can experience the performance-limiting effects of dehydration after losing as little as one percent of their body weight. You need to drink about half your body weight in fluid ounces during the course of a day. If you weigh 120 lbs., for example, you would need to drink 60 oz. of water throughout the day. Prepare for a workout by consuming 16 oz. of water two hours before you plan to exercise and 8-12 oz. of liquids ten minutes before your workout. Remember to drink even when your body is not signalling thirst; your fascia will thank you for it.
Bring water along with you to drink while on your run and try to keep it at room temp. Room temperature liquids are more slowly absorbed by the body, but they keep you hydrated longer and maintain your body at a more optimal hydration level. To keep the water in your bottle from turning into a slushy, try using an insulated water bottle. You can also add a little salt or sugar to water to lower its freezing point. This is also the time when a sports drink –– avoid sugar-free varieties –– can be useful.
Remember, hydration is just as important during the winter as it is in the summer: have a plan, stick to it, and drink up!