Fueling Your Run on Race Day

by Tanis Smith, Road-racer, B.H.K., B.Ed., CanFit Pro PTS

From my own racing experiences over the years, I know that race day nutrition can play an integral role in performance. Too much, too little, too soon, or too late are all issues that can drastically slow you down on race day. There are so many facets to nutrition that one could focus on even up to a week before the big race. For simplicity sake, I will be focusing on race day itself.


When it comes to race morning, the best thing you can do is stick to your routine. This is not the day to try that new superfood smoothie. Race day nerves are going to make it hard enough to digest food properly as it is, so try to stick to carbohydrate rich foods (e.g. toast, muffins, bagels, oatmeal) that are easy on the stomach. Aim for a 300-400 calorie meal when you wake. Timing is important as well - try not to have your breakfast any later than 2 hours before the race. If you normally drink coffee then have your morning cup of joe!

Foods to avoid:

  • Dairy
  • High-fat foods
  • High-fiber foods (vegetables)
  • Spicy foods
  • Pears
  • Apples

If you become hungry close to your race, try half a banana or a granola bar. Try not to eat within the hour before a race. Interestingly enough, if you eat within the hour you will trigger an insulin response in your body. What that means is that your body will start to shift the blood flow in favor of digestion instead of to the exercising muscles, which can negatively impact your performance on race day.

Don’t forget about your fluid intake! Just as any other day, you should be taking in fluids consistently throughout the day. Remember, we aren’t camels, so there’s no need to excessively consume water race day. If you’re like me then you will probably have multiple bathroom stops before the race due to race day nerves. If you are chugging water you will waste your morning in the line-ups. My best advice is to consistently drink water and stop about one hour before the race with only taking small sips to wet your mouth.


When exercising, your body will use two main sources of fuel – fats and carbohydrates. The problem with fat metabolism is that it’s a slow process, which makes it inefficient to use when working at intensities over 60-70% of our VO2max. This means that when racing, the primary fuel source is carbohydrates (CHOs). In fact, research shows that carbohydrates are the dominant fuel at exercise intensities over 75% of VO2max and can become a limiting factor after 90 minutes of exercise. A great take away point here is after 90 minutes – therefore, mid-race fueling for your 5 or 10-kilometer race isn’t necessary. Fueling will become a factor in distances of half-marathon (21.1km) or further.

If you are racing these distances and want to fuel there are many options: gels (with and without caffeine), sports drinks, sport beans, gel chews, etc. Research recommends that you take in 30-60g of CHO per hour during racing. Most gels have about 20g per package so approximately 1 gel per hour. However, excessive consumption of fluids and CHOs may result in GI problems. I highly recommend testing your planned race day nutrition routine during multiple workouts beforehand so that you can see what types of fueling work best for you and in what combination. For myself, I usually will ingest half a gel, 2 chews, or 1 cup of Honeymaxx starting at the 7 kilometer mark and every 3 kilometers after that.

Besides performance, fueling properly during a race is important for your health. There have been several cases of people having serious health issues and dying during races due to a condition called hyponatremia. Hyponatremia is when the sodium concentration in the blood stream is too low. Drinking too much pure water causes sodium to leave the cells and water to rush into them, causing swelling in places there shouldn’t be (i.e. the brain). Signs and symptoms of hyponatremia include: nausea and vomiting, headache, confusion, fatigue, muscle weakness, spasms or cramps, seizures, and possibly coma. Luckily there’s an easy way to avoid this. People who often fall into this trap are inexperienced runners who take pure water from most water stations during a marathon. Instead of grabbing the diluted water, grab the sports drink instead to avoid overhydrating. This is why products like Honeymaxx are great; you will balance your intake of water with electrolytes and the carbohydrates will provide energy for working muscles to enhance performance and help speed recovery.

Tanis Smith is an aspiring national runner from Oshawa, Ontario.   She holds a Human Kinetics degree from the University of Windsor and is a CanFit Pro certified personal trainer.   She's also fast...with a half marathon personal best of 1:22.  You can follow Tanis at tanissmith.com.