Race Day Nutrition

What’s Included?

  • DO:
    • Hydrate
    • Fuel
    • Find a bathroom
  • DO NOT:
    • Try anything new on race day

You’ve spent weeks preparing for your race, and now you don’t want to let your pre-race nutrition mess it up… But HOW do you make sure you’re ready on race day when it comes to fuel and nutrition? Nailing your pre-race nutrition can help you feel strong throughout your race and prevent any unwanted GI issues on race day. While everyone is unique and may have different needs, there are a few general DO’S and DO NOT’S that can help you prepare for your best race day experience.


Hydration is important all the time, but especially for athletes! Adequate hydration is water plus electrolytes (particularly sodium and chloride).

As little as 2-3% of fluid losses through sweat during a race can significantly decrease performance, increase perceived effort and core temperature. These determinants are most notable during events in the summer when it’s hot out and at elevation, mildly noticeable in temperate conditions, and are less noticeable when competing in cold or cooler weather climates.

Electrolytes like sodium are important as these help your body hold on to water. You can also lose small amounts of potassium, magnesium, iron, and calcium through sweat losses. Dehydration can also contribute to GI upset and issues on the run.


Make sure you wake up early enough to eat something you know sits well for you. By the time race day rolls around, you should have been practicing your pre-run nutrition on your long runs. As you approach race day, you should decrease fiber and higher fat foods and increase carbohydrates.

Pre-exercise/race: 45 min – 2 hours (top off your glycogen stores!)

  • Limit fat and fiber containing foods. Foods high in fat and fiber (think nut butters, avocado, butter, whole fat dairy, fruits/veggies, whole grains etc) take longer to digest and may not sit as well and cause GI issues.. Depending on the length and purpose of your run, and how much time you have to eat and digest before your run, some of these things may not bother you, but choosing easy to digest carbohydrates should be a priority and is more likely to be well tolerated.
  • Easy to digest Carbohydrate: half to full bagel, 1-2 slices toast, fig bar, poptart, applesauce pouch, pretzels, low fiber grains, cereal
  • Depending on how far out you are from your run (time wise) may determine serving sizes or amount. You want to choose something that sits well with you.

Check out https://www.teamusa.org/nutrition “athlete plates” to see a visual of what your plate should look like as you’re preparing for a hard effort.


It’s always a good idea to give your body enough time to wake up and digest your pre-race meal/snack. Give yourself some time to go to the bathroom before your race, whether that’s at home, or arriving early to the race. This can hopefully help decrease any bathroom emergencies once the race has started.


You’ve probably heard it before, but it’s important to not try anything new on race day, and that goes for your nutrition too!

What we eat the night before and the morning of can both impact how we feel during our race. Especially for those that have a history of GI issues on the run, it’s important that fueling strategies are practiced before race day so that you can go into your race morning knowing what to expect and knowing that everything will be well tolerated.

Struggling with your nutrition on the run? Find a sports dietitian that can help you work through your fueling and identifying areas that could be negatively impacting you!

Amy Haas
Run with Aim, LLC
UESCA Certified Running Coach
NASM Certified Personal Trainer
NASM Certified Nutrition Coach

Information written & verified by:
Katelyn Biros
Registered Dietitian