A dietitian’s tips for fuelling before and during your race

By Courtney Berg

As a Registered Dietitian, I know fuelling for race day is crucial for optimal performance but getting this right can be complicated. Below are some of the dietitian-approved nutrition strategies I talk to clients about utilizing before and during their races.

Note that experimenting with anything on race day is never ideal. It is recommended to practice day-of and in-race fuelling in race-effort workouts before your race. For instance, look up when your race is scheduled to start and do one or more race-effort workouts at that time where you practice what you will eat for breakfast and when. This should include thinking about race-morning hydration and caffeine consumption. For races longer than 60 minutes, it is recommended to consume fluids, carbohydrates, and electrolytes during the race. Look up what will be available on the course or plan to bring your own fuel and practice consuming these in race-effort workouts.

The Day Before The Race

  • Consume carbohydrates: Include carbohydrate sources in meals and snacks the day before the event (and up to two days for events >90 minutes). The purpose of including carbohydrates is to replenish muscle and liver glycogen stores, which serve as a primary source of energy during endurance activities. If your event is >90 minutes, you may benefit from carbohydrate loading whereby you considerably increase your carbohydrate intake up to 48 hours before the event. Some examples of carbohydrate sources include potatoes, oats, rice, rice cakes, quinoa, whole grain bread, sourdough bread, fruits, and more.
  • Focus on hydration: Drink plenty of water the day before to maintain hydration status. In addition to water, you may choose to consume fluid and electrolyte-rich foods like smoothies, soups, vegetables, fruits, and milk or milk alternatives. Hydration from both fluid and electrolytes is important to consider the day before the race to maintain hydration and circulate nutrients to the muscles!
  • Avoid excess fiber: While fiber is an essential nutrient for overall health and digestion, consuming excessive fiber before a race can lead to gastrointestinal issues during the event that can compromise performance. This is especially relevant for individuals increasing carbohydrate intake the day before the event. Registered Dietitians consider a very high fiber food to be one that has >5g of fiber per serving. For example: it may be beneficial to avoid fiber-added granola bars or protein bars, fiber-added candies, beans and lentils, some fruits like berries and apples, sprouted grain breads, chia seeds, or fiber-added breads, cereals, and wraps.
  • Stick to familiar foods: Resist the temptation to try new foods or meals the day before race day. Consume foods that you are familiar with to reduce the risk of unexpected digestive issues before or during the race. A familiar pre-race meal can boost confidence as you can better predict how your body will feel and perform!

Race Day

  • Optimize your pre-race meal: A pre-race meal should provide sources of carbohydrates alongside small amounts of protein, fiber, and healthy fats. The amount of carbohydrate included in the pre-race meal will depend on the individual. Some examples of pre-race breakfast include:
    • A bagel with a thin smear of peanut butter and topped with sliced banana and a drizzle of honey.
    • Overnight oats with oats, honey, milk, protein powder, Greek yogurt, and fruit.
    • An egg-white omelette with sourdough bread and fruit
    • Oatmeal prepared with a higher protein milk and topped with banana, maple syrup, and a few walnuts
  • Consider the timing of breakfast: The amount of time you have to digest your meal before the start of the race will influence how much you eat as well as the amount of protein, fiber, and fat in the meal. Protein, fiber, and fat significantly slow digestion, which is not optimal leading into an endurance event! If you have <60-90 minutes to digest the pre-race meal then it is recommended to reduce protein, fiber, and fat in the meal. For example, instead of having overnight oats that include fat and protein sources such as nuts or seeds, protein powder and Greek yogurt, you may instead prepare plain oatmeal with simple carbohydrates toppings such as banana and honey.
  • Consider a pre-race top-up: Some athletes choose to have a pre-race carbohydrate top-up immediately before the start of the event. Experiment with this strategy in training to determine if it is a good fit for you! For example, a carbohydrate gel or simple carbohydrate source like honey, dried fruit, or a fruit bar consumed up to 15 minutes before the start of the race.
  • Focus on hydration: Hydrate immediately upon waking by drinking water and/or electrolytes. Continue to drink fluids with your pre-race meal and before the start of the race!
  • Consider caffeine: Ingesting caffeine 30-60 minutes before a race can offer performance benefits for many athletes. It is important to understand your personal tolerance as too much caffeine can lead to jitters, anxiety, or gastrointestinal discomfort. Avoid experimentation on race day and stick to caffeine sources and amounts you’ve tested during training!

During The Race

  • Fuel sources during the race including carbohydrates, electrolytes, and fluid depends on the duration of the race. Before planning for intra-race nutrition, consider the approximate duration of your event!
    • For races <60 minutes: You do not require fluids, carbohydrates, or electrolytes during the race. Your pre-race meal and fluids will provide the energy and hydration needed for the event. While intra-race nutrition is not required, you may choose to consume fluids and electrolytes if you prefer or if they are offered along the course.
    • If your race is >60 minutes: Fluids, carbohydrates, and electrolytes are recommended during the race. Individual needs for intra-race nutrition vary based on intensity, duration, and individual sweat rate and composition. Speak to a Registered Dietitian to refine your strategy! Consider the recommendations below as a starting point and practice your intra-race fuelling strategy during training:
      • Fluids: 400-800mL per hour
      • Carbohydrates: 30-60g per hour (up to 90g per hour in some scenarios)
      • Electrolytes: 300-700 mg of sodium per hour (“salty sweaters” may require additional sodium)
  • If you have a high sweat rate, are a “salty sweater” (ie. excess sodium losses in sweat) or are running in hot and humid environments you may experience increased losses of fluid and electrolytes. In these scenarios, you may benefit from consuming the higher end of the range for fluids and electrolytes. Speak with a Registered Dietitian to create a personalized intra-race fuelling strategy!


Having a fuelling strategy for race day is important to optimize performance. In review, the key nutrition principles to consider to optimize your race performance include:

  • The Day Before: Consume adequate carbohydrates and fluids the day before the race. Limit excess fiber consumption and stick with familiar foods to avoid gastrointestinal discomfort leading into race day. If your event is >90 minutes you may benefit from carbohydrate loading.
  • The Day Of: Consume a carbohydrate-rich meal 60 minutes or more before the event. If you have <60-90 minutes to digest your pre-race meal you may benefit from limiting sources of fiber, fat, and protein as these nutrients can slow digestion and lead to gastrointestinal issues during the day. Maintain hydration status leading into the event by consuming fluids before the event. Consider caffeine 30-60 minutes before the race and a pre-race carbohydrate top-off if these strategies worked well for you during training!
  • During The Race: Intra-race nutrition including carbohydrates, fluids, and electrolytes is not required for events <60 minutes. If your event is >60 minutes, you will benefit from supplementing with fluid, carbohydrate, and electrolytes during the race! The duration, intensity, weather conditions, and personal sweat rate will influence recommended amounts of fluid, electrolytes, and carbohydrate supplementation.

Race day nutrition is highly individual and requires experimentation to determine the best approach for you. Consider the recommendations in this article as general principles for race day nutrition and consult with a Registered Dietitian to customize your fuelling strategy!


Courtney Berg is a Registered Dietitian and the owner of Vitality Nutrition, a collective of Registered Dietitians supporting clients in-person in Saskatoon and Regina and virtually across Saskatchewan. Courtney and her team of nutritionists incorporate a unique and meaningful approach to food, fitness, and performance that empowers their clients to build life-long habits and create lasting results.