Race Day Nutrition Plan: How to Adjust Fueling for the Weather

You are incessantly tied to the weather channel app which is signaling that race day is finally approaching and so are less-than-ideal weather conditions. Beyond the 25 mile per hour wind gusts, you are likely dealing with wet and humid conditions throughout the race. While you cannot control the weather, you can adjust your race day nutrition plan to help conquer mother nature. Review the following race day nutrition strategies so you feel confident even in the harshest weather conditions.

Importance of Proper Nutrition on Race Day

Nutrition can make or break a race, even for the best-intentioned athletes. Throughout your training cycle, you fueled well and also executed your carb load effectively heading into race day. In addition, your pre-race morning meal is spot on. However, given the less-than-ideal weather forecast, it is important to recognize that your race day nutrition plan may need a few tweaks. Weather conditions including extreme heat and humidity and frigid temperatures can lend itself to nutritional challenges which may precipitate underfueling and poor performance.

Effects of underfueling due to subpar race conditions can be severe. Dehydration, poor recovery post race, and even an unwanted trip to the medical tent to name a few. Your race day nutrition plan needs to account for all factors, including impending weather conditions to ensure best case scenario for you. Adequately fueling even during the harshest weather condition can help to:

• Reduce fluid losses
• Delay the onset of fatigue
• Prevent dehydration-associated injuries
• Lessen the risk of heat stroke, stress, or illness
• Improve cardiovascular outcomes such as a decrease in heart rate and maintenance of blood volume

Adjusting Fueling for Race Day- The Basics

Before crossing your fingers and hoping for the best, be sure to review the basics below so that you feel confident in your race day nutrition plan. A few important considerations to start with:

Stay adequately hydrated at baseline day in and day out.

This can be much more challenging in cooler weather environments when thirst signals are not as strong. According to the National Academy of Sports Medicine, the recommended fluid intake for men is 125-130 oz/day (approx. 16 cups) and 91-95 oz/day (approx. 12 cups) for women. Remember that this number can increase depending on your baseline training duration and intensity. Start tracking your water intake in an app or journal over the course of a few days and training sessions. This will give you a good starting point to go off of to make sure you are staying well-hydrated heading into the race

Reference our hydration guidelines article to calculate sweat rate so you can better estimate fluid and sodium needs during the race. Typically we encourage most endurance athletes to calculate their sweat rate in varying weather conditions, including hot and cold weather. This ensures you can troubleshoot and are well-prepared for what mother nature may bring come race day

Practice and prepare on repeat.

Ideally practice your race day nutrition plan on most, if not every, long run or ride throughout your training cycle. For most endurance athletes the general recommendations are to aim for:

• 60-90 g of carbohydrates per hour,
• 200-500 mg of sodium per hour, though potentially more if you’re a salty sweater. Your electrolyte needs will vary based on your body size, intensity, duration of the race, and the weather of course
• At least 5-10 oz of fluids every 15 minutes during the race 
• Simple carbohydrates such as energy gels and sports drink beverages are the most convenient options for hitting these nutrition goals. Consider experimenting with a wide range of sports nutrition products to see what your body tolerates in varying weather conditions. Flavor fatigue is common amongst athletes so be sure to experiment with varying flavors of the same brand
• Ensure you have the right storage gear for the race. For cyclists, this may warrant an investment in a front hydration system for the bike. For runners, this may be an extra bottle (or two) and for trail runners, this may imply an extra bottle (or two) tucked away in your hydration vest. As any mother runner will tell you, “It is far better to be over prepared than underprepared!”

Adjusting Nutrition for Hot and Dry Weather

Research shows that in dry climates, sweat generally evaporates without wetting the skin surface by the heat supplied by the skin surface. No cooling effect is achieved and the body temperature rises steeply. Furthermore, your sweat rate will likely be increased in hot and dry weather conditions therefore fluids and electrolytes are imperative.

Preparation strategies heading into hot and dry weather:

• Emphasize hydration throughout race week. Remember that non-alcoholic and non-caffeinated beverages typically “count” as hydrating beverages. So be sure to include fruit juice, sports drinks, milk or milk alternatives and even fruit smoothies heading into race day. Furthermore, these options provide you with much-needed electrolytes including potassium, calcium, and magnesium. Consider adding an electrolyte mix to your water bottle to sip on during your carb load and also race day morning
• Increase your intake of salty foods and snacks prior to race day, including in your carb loading plan. Pretzels, crackers, bagels, pancakes, and high-salt condiments such as soy sauce and teriyaki sauce to name a few. It is also okay to be extra generous with the salt shaker at meal times
• Sip on an electrolyte-rich sports drink throughout race day morning. Reference our guide to various electrolyte mixes for a few ideas
• Throughout the race, incorporate higher-salt sports nutrition products including gels or sports drinks. Reference our marathon nutrition post for fueling your body best on race day
• Dry conditions may imply that you are headed to higher elevation, in which your fluid and electrolyte needs are even greater. Low humidity at most altitude locations and increased respiratory losses can predispose athletes to greater dehydration risks. If this is the case, ideally you want to aim for at least 25-50% more fluids than you would normally drink

Fueling Strategies for Humid Weather

The hotter and more humid the weather, the more electrolytes you will lose through sweat. Preparation strategies heading into humid weather:

• As with hot and dry weather, stay adequately hydrated at baseline. In addition to bumping up your fluid intake, consider including more hydrating foods such as fruits and smoothies in your carb loading plan prior to race day
• Your sweat rate is likely increased and for some individuals, may be double the sweat rate in normal weather conditions. Fluids and salt will need to be a priority throughout the race
• Opt for high-carb, high-salt energy gels and sports drinks in your race day nutrition plan. Salt tabs or capsules are also an easy and portable way to boost your sodium intake during the race. These can be easily stored in a bike jersey, fuel belt while running, or hydration vest if on the trails

Adjusting Nutrition for Rainy and Wet Conditions

That sneaky humidity will likely increase your sweat rate and need for fluids and sodium replenishment. The wet conditions can make the logistics of carrying fluids and solids a tad more challenging.

Preparation strategies for heading into rainy and wet conditions:

• Prepare similar to humid weather and be sure to optimize hydrating beverages– and solids
• Carrying your fluids poses a challenge and may make the logistics a tad more slippery. If you are on the bike, you may consider sticking with mostly liquid nutrition and investing in a front hydration system. If using bottles, opt for bottles that are easier to grip or utilize extra sticky tape on the outside of the bottle. For runners, be sure to opt for a hydration vest, handheld water bottle with wrist strap, and fuel belt to store your extra gels. If your energy gels are difficult to open in wet conditions, consider carrying your solids in a plastic or reusable bag. Dried fruit, fruit leather, trail mix, and pretzels are a few options
• Avoid salt tabs as these easily dissolve in wet conditions and stick with higher-salt sports drinks and gels or salt capsules

Adapting to Cold Weather 

During cold-weather races, the warm clothes you wear may contribute to a rise in body temperature that increases your sweat rate. Furthermore, your hydration can become compromised in cold weather through physiological mechanisms including cold-induced diuresis and fluid losses from your lungs. 

Preparation strategies heading into cold weather:

• Fluids may be less readily available at cold weather events. Even if fluids are available, when the temperature is below 32℉ the liquid will begin to freeze. Drinking in colder weather may also be uncomfortable due to the logistics of keeping your hands from freezing (though disposable hand warmers can certainly help with this). Thirst cues are often decreased in the cold weather and you may not so readily crave fluids. Though optimal hydration can be a challenge in cold weather, you can follow a few warming strategies. Consider warming your sports drinks before racing and placing the liquid inside of an insulated bottle. Experiment with a variety of warm drinks and flavors that appeal to you and rotate through flavors to avoid fatigue
• For trail runners, if you are using a hydration vest, opt for one with an insulated hose as well as bite valves covered with insulated caps. In weather below 32℉ make sure that you fill the fluid reservoir with warm fluid. You should also blow back into the drink tube after you have taken a hydrating gulp to prevent the fluid from sitting and freezing in the drink tube
• Very little information is available on sodium losses when training in cold weather though it is beneficial to know your estimated sweat rate in cooler weather conditions. Consider measuring this heading into race day 
• If you are packing solid food options, be sure to pack a few snacks that won’t freeze. These options are great if you are on the bike or hitting the trails: turkey and cheese bagel sandwich, almond butter and jelly sandwich, blueberry muffin with dried banana chips or even breakfast bars such as Belvita

Fine-tuning your race day nutrition plan

Repeat after me- “On race day, I will avoid any new foods and beverages that I have not tried in training.” Adequate practice and preparation are key for what to eat during a race. Ideally you have practiced this on most, if not every, long run or ride throughout your training cycle. Experimenting with new sports nutrition products and foods on race day can result in unwanted consequences such as gastrointestinal issues and underfueling. It is important to practice your race day nutrition plan on repeat. Be sure to also review our tips for traveling to races, altitude, and race day fuel plan.

Ready, Set, Go!

As athletes, we harness the ability to maintain flexibility with our race day nutrition plans. Each individual has very unique nutrition needs and it is important that you feel just as confident in your fueling plan as you do with your training and racing plan. Nailing down your race day fuel and nutrition plan requires consistent practice and patience. Consider working with a sports dietitian so that you can better tailor a race day fuel plan that works well for you!