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By: Paul Wilkinson

How To Fuel Your Energy During a Triathlon

Properly fueling (taking in calories) before and after a training session or race can be fairly simple if done correctly, but what about fueling during a race? In the following I will explain exactly how to fuel for endurance performance.

Fueling workouts or races an hour or less in duration:

For an event lasting an hour or less such as a sprint triathlon,  if you had a good meal before your training session or event, you don’t need any additional fuel (calories) besides water. In fact, intermediate to advanced level athletes can even go as long as 90 minutes of exercise without any fuel and they perform just fine. The only time I recommend an athlete consume fuel during events an hour or less in duration is: A. They didn’t consume any food before their training session or race or B. As a mental boost to get to them to finish.

Fueling workouts or races 2.5 hours or less in duration:

For an event lasting 2.5 hours or less, such as an olympic triathlon, I do recommend taking in some calories during the event to fuel your performance. For most triathletes a water bottle filled with 200-300 calories of a sports drink like HEED or GU Brew,  or 2-3 energy gels works just fine on the bike portion of an olympic triathlon. For the run portion of an olympic triathlon If your total 10k time will be under an hour you don’t necessarily need to take in any calories. However, I would bring a gel or prepare to use one provided on the course just in case. If your total 10k run time will be over an hour then I definitely recommend taking in 100-200 more calories on the run in the form of gels or liquids.

Fueling workouts or races over 4 hours in duration:

For an event lasting over 4 hours such as a half ironman or ironman triathlon, proper fueling is very important for performance. I recommend athletes take in anywhere from 250-450 calories per hour on the bike portion, and 200-300 calories per hour on the run portion of a half ironman or ironman triathlon.

The fuel you take in on the bike can be either from energy bars, gels, liquids, or a combination of these. I personally stick with gels because liquids can be rather heavy. I still like to stick with just 2 water bottles on the bike. To mentally break things up I will have a bar or some other solid food at the end of every hour.

When fueling on the run portion of a triathlon I recommend avoiding solid foods, as these are hard to chew as your running. Also the stomach sloshing running can cause makes liquids or gels a much better option. If you can, try to use the fuel provided on the course so you don’t have to carry gels or other fuel with you.


The following is an exact race day meal plan for a Half-Ironman Triathlete:

Pre-race meal: 1 banana, 2 rice cakes with almond butter

During Race:

1 Gu Roctane gel right before the Swim

3 Gu Roctane gels every hour on the bike with a few honey stinger chews at the end of each hour.

1 gel every 30 minutes on the run (using the gels on the course).

Post-race meal: Sweet potato fries and some grilled chicken.

About Brad Haag

Brad is a certified USAT triathlon coach, a certified USAC cycling coach, and a certified NCSF personal trainer. Brad specializes in coaching endurance and warrior class athletes to peak performance. He can be found at HaagsAthletics.com.

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