Hydration is complex and dynamic, especially for runners and endurance athletes. Drinking when the weather is hot outside can be more intuitive, but not necessarily during cold weather running.
Picture this: It’s a hot summer day in mid-July and you break a sweat just stepping outside. You begin your run, and 10 minutes in, your shirt is soaked, and sweat is burning your eyes. Thirst kicks in, and you already know that as soon as you return home, you need to get plenty of fluids in to replenish all that was lost.
Now, picture a crisp fall morning. It’s 45 degrees, the sun is shining, and you head out in your favorite running tights and long-sleeved shirt. You strip your ear warmer and gloves 20 minutes in but return from the run with minimal sweat stains. You drink a glass of water when you come in to coat your dry mouth, but don’t think twice about how much fluid you may have lost.
With winter weather rolling in, it’s important to understand that whether it’s 90 degrees or 40 degrees, maintaining good hydration is critical in feeling and performing at your best.
Hi! My name is Sarah Katz. I am a registered dietitian and heavy sweater who struggles to stay hydrated while running in cold weather.
In this blog, you will learn four steps to help you stay hydrated during cold weather running.
Step 1: Understand Fluid Loss
Step 2: Monitor Signs & Symptoms of Dehydration
Step 3: Create a Hydration Plan
Step 4: Make Hydrating Fun
First, let’s discuss how to understand fluid loss.
Step 1: Understand Fluid Loss in Cold Weather Running
One of the most common reasons for dehydration in cold weather is lack of awareness. When it’s hot outside, and you are sweating heavily, it’s easy to see sweat rolling off your skin or dripping on the ground. When it’s cold, the visual losses may not be as noticeable. Though sweat rates may be lower, you still lose plenty of fluids from breathing and bathroom breaks!
Another common reason for dehydration in the cold is reduced thirst sensations. Your body works hard to keep your core organs warm when it is cold. Because of this, you may notice that your hands and feet get cold first. When blood rushes to the core to keep the body warm, the body may mistake this extra blood for water, mitigating the need for a thirst response. (1) Though thirst is not a great indicator of hydration needs, it is a major factor influencing when and why athletes choose to drink.
Wondering how much fluid you lose during training?
Try weighing yourself before and after! This simple calculation can be used to determine your sweat rate and fluid needs in various conditions:
Sweat Rate = 16 x (Pre-Exercise Bodyweight – Post-Exercise Bodyweight) + Fluid Intake (fluid ounces) – Urine Volume (fluid ounces) / Exercise Time (hours)
Example: A runner begins a 2-hour run at 150 pounds and ends at 148 pounds and drinks 16 oz of fluid throughout the run with no bathroom breaks.
Sweat Rate = 16 x (150 lbs – 148 lbs) + 16 fl oz – 0 oz / 2 hours = 24 oz per hour
Sweat loss varies significantly between athletes, ranging from less than 1 liter to over 3 liters per hour. If you are a heavy sweater, you may also want to consider sweat sodium testing to determine your individual electrolyte replacement needs.
Understanding fluid loss, or sweat rate, is the first step in determining your hydration needs.
Next, let’s discuss some signs and symptoms of dehydration to look out for during cold weather running.
Step 2: Monitor Signs & Symptoms of Dehydration
Knowing the signs and symptoms of dehydration helps you to monitor how well you’re hydrating! As an athlete, fluid needs change depending on your training, environment, fitness level, and so much more.
If you are training in cold weather, look for these signs and symptoms that may indicate dehydration:
- Dry skin and chapped lips
- Early fatigue
- Dark-colored urine
- Elevated heart rate
Keeping note of how much fluid you drink throughout the day can also be a great way to assess your hydration status and help you develop a hydration plan.
Monitoring signs and symptoms is a practical way to gauge hydration. Next, let’s take a step further and discuss creating a hydration plan.
Step 3: Create a Hydration Plan
Now that you know what influences fluid needs and signs to look out for, you can create a hydration plan. Having a plan can help you feel better during your run and recover faster and avoid relying on unreliable measures, such as thirst, to indicate the need to hydrate.
Develop a plan based on your individual needs and how much to drink before, during, and after training sessions. You can also set a daily goal to maintain consistent hydration throughout the day and not just around training.
If you need help creating an individualized hydration plan, meet with one of our team dietitians. You can also consider a sweat sodium test to determine how much sodium you lose per liter of sweat. This is a great tool to individualize how much fluid you need and how much sodium you need per hour during training and racing.
Creating a plan is a great tool, but sticking to it isn’t always so easy. Finally, let’s discuss some ways to make hydration fun!
Step 4: Make Hydration Fun
It’s no secret that plain water can be boring. Water tastes great when you are hot and thirsty, but a cold glass of water doesn’t always do the trick when it’s cold outside. Try some of these strategies to add some variety and make hydrating more fun, especially during cold weather running.
Strategies to Make Hydrating Fun During Cold Weather Running
- Add fresh fruit to your water.
- Warm your water with lemon and honey and carry it in an insulated flask during runs.
- Hydrate with water-rich foods like soups.
- Sip on flavored teas throughout the day.
Hydration is complex and individualized but essential to your health and performance during cold and warm weather. Let’s bundle up these tips!
Bundle Up Hydration for Cold Weather Running
Understanding that hydration is just as important during cold weather running as it is in hot weather will help you all year. Remember these four steps to help you stay hydrated during your cold weather running:
- Understand Fluid Loss
- Monitor Signs & Symptoms of Dehydration
- Create a Hydration Plan
- Make Hydrating Fun
As always, our team is here to help with your fueling and hydration needs. Sign up today for a free 15-minute consultation to chat about how we can help you reach your goals!
Reviewed by: Jena Brown, RD, CSSD, LD
