How To Properly Fuel for a Full-Distance Triathlon


Nutrition in any race is key for a successful outcome. For a full-distance triathlon (2.4 mile swim, 112 mile bike, 26.2 mile run), it’s just as important as the physical training. Just like one’s prep for a great swim, bike and run, fueling for a race has to be practiced, the gut trained and done in training. A key for any athlete is to make sure they’re getting enough fluid and sodium. These two areas of focus are usually underestimated and can make or break a race. This blog will break down how to properly fuel for a full distance (Ironman) triathlon.

Make a Plan

While running-specific, a study (2013 Hansen et al.) found that marathon runners who followed a scientifically based nutritional strategy were approximately 5 percent faster than runners who self-selected their nutritional strategy.

While having a fueling game plan is extremely important regardless of the distance of a triathlon or training session, the longer the duration is, the more important having a fueling strategy is. The specific types of drinks and foods ingested during a race need to be tried and evaluated during training.

When I first got into triathlon, I didn’t know much about nutrition. I saw the sports drinks and the gels, and took in a gel here or there in training when I felt I was hungry. Often times, I would go out like a hero on the bike for an hour, and crawl back home. It wasn’t pacing, it was because I wasn’t fueling. I thought, like many, if I didn’t eat in training, I would get leaner.

One of my first long distance triathlons was a horrendous experience. I flew to Australia for the Ironman. Pre-race I felt I was doing everything right. I had carbohydrates – including watermelon (for the water content of course!), rice, crackers and everything I thought would be simple before the race.  During the race I had water on the bike, a few gels and grabbed a Coke halfway through the bike. Unbeknownst to me, I would be CRAWLING my way to the finish line on the run.  At about mile 8, I really had to go to the bathroom and quite literally lost the ability to hold it. It was terrible. I ended up running/walking the remainder of the 26.2 miles soiled. My stomach couldn’t take in food either. I was a mess. It was this race that got me to research and find someone to help me with my nutrition.  

Working with my current coach, Jesse Kropelnicki of QT2systems, I have found the applications below to be sound and work for me. The key is you have to train your gut, just like you would train for swim-bike-run. You have to fuel in training as you would in your races – day in and day out.

Using a sports drink as a main source of hydration, with appropriate caloric and sodium content, will fulfill the needs for appropriate hydration and sodium.  Appropriate sodium content is roughly 600mg per 24 oz water bottle, along with roughly 50g of carbohydrate in the mix. PowerBar Perform at full strength is one such product.  Many athletes make the mistake of not drinking enough and therefore become dehydrated on the run. Another mistake that many athletes make is they drink plain water on the bike which supplies zero nutrition you need (carbohydrates and sodium). As a coach and professional athlete, I don’t drink water in races and training. As noted in UESCA coach certifications, many sport drinks have the right amount of sodium content and carbohydrate for adequate digestion and limits GI distress. When using just water, you are really playing with unknowns, since your blood sugar will go up and down, and sodium content is null.  You want to know that you’re fueling your body adequately throughout the entire race.


In the days leading up to a race, I stay away from large amounts of fat and fiber. I usually have a large pasta dinner or rice with chicken two nights before the race, leaning toward more carbohydrates than normal. The day before the race I opt for a large breakfast – pancakes, syrup, 2 eggs, and toast. My largest meal is always this breakfast where I then taper my intake of food from there. I snack on pretzels for carbohydrates and sodium content. I stick to very plain foods.

I eat 3 to 3.5 hours before the start of the race and ingest simple carbohydrates. Before the swim, I eat a PowerGel that has 25g of carbohydrates. During the race, I like to keep things simple. I use my own nutrition and rely on what is on course for hydration.

Days Leading Up To The Race

Two days prior to the race, below are some foods/drinks that I’ll consume.

  • 1 veggie wrap
  • 1 pear
  • Chicken breast (small)
  • A few cashews
  • PowerBar
  • Sports drink 50g
  • Greek yogurt cup
  • A few crackers
  • Sourdough bun
  • Turkey slices and pesto sauce
  • Rice crackers – handful
  • 2 pieces homemade banana bread
  • 3oz pretzels
  • 3oz rice crackers
  • Salmon packet

Below are the things that I will typically eat the day before the race:

  • PowerBar
  • Almond milk 1.5c
  • 2 servings of nutrigrain waffles (low-fat)
  • 2 eggs
  • 3 tbsp syrup
  • 1 gluten free waffle
  • Sports drink 50g
  • 40 rice crackers
  • 3 oz pretzels

— all before 11am

  • Powerbar
  • Sourdough bun
  • 18 rice crackers

Dinner at 4pm:

  • Cup of rice and small chicken breast

Race Day!

The morning of the race, I’ll have the following:

  • Applesauce, scoop of whey protein
  • 1 sports drink
  • 1/2 bagel
  • 1 banana
  • Sip on sports drink up to the race start
  • 15 minutes prior to the start – 1 gel

During the race, I’ll consume the following:

Bike: 8 to 11 gels with sports drink throughout

Run: 3 to 5 gels, 1 every 30 minutes, use the on-course fluids


Any plan should be focused on energy and hydration. Aiming to eat/drink every 10-15 minutes is a good starting point, looking to consume 25g carbohydrates every 30 to 60minutes – depending on practice and body weight.

I can’t stress enough the importance of practice before race day. Performance issues usually are from nutrition intake, improper fuels, and/or not pacing correctly. My recommendation is to really try products that are made for racing already. SIMPLE is key.  Sports drink and gels like PowerBar Perform and PowerGels have an appropriate amount of carbohydrates and sodium. 

Train The Gut

I often hear from athletes that they can’t stomach or use gels. I was the same. If you don’t ingest these on a regular basis, eating one for race day or sporadically will not work for most people. After dialing in my nutrition and slowly building up the amount of carbohydrates I could ingest in an hour, I was able to follow the above nutrition plan in a race. The gut is very adaptable but you need to give it time to adapt! This takes daily nutrition and fueling that replicates what you will do on race day. If ingesting this many carbohydrates is new, I recommend starting slow. Have only sport drinks only for your first few rides. Then, slowly add a gel every hour. From there, work your way to 30-60g of carbohydrates an hour.


A note on caffeine. Yes, I’m a habitual user and love it! During a race, I typically consume more of this during the last half of the bike and into the run. I usually max out on 350-500mg for the day. I use gels that have caffeine in them. This is also something to practice and utilize in training. Caffeine is a great tool to keep alert and focused in a race. It also helps stimulate you when you start to fade – typically the latter part of the race. To maximize its effectiveness, I try to limit my caffeine intake leading into a race, about 3-5 days before.

I wouldn’t recommend stopping cold turkey, but slowly dropping your caffeine intake starting around five days prior to a race may be helpful.  Focus on more sleep and recovery. I typically go from a few cups of coffee to 2 cups and decaf, to one cup and decaf, to none. This tapering, limits any withdrawal effects for me.


After the race and during my training, I focus on eating within 30 minutes of finishing. A recovery drink and fuel that has carbohydrates and protein helps with the recovery process. I typically ingest a recovery drink made with 4:1 ratio of carbohydrates to protein (at least 15g of protein). I like fluid form because it’s very easy to get down, even when you think you can’t ingest any more food. Post race food is typically pizza – which I definitely eat. The more fuel you can get in post-race and ideally within a few hours will help with your recovery process. Splurge, eat and relish in what you just accomplished!

NOTE: Nutrition and hydration are very individualistic in respect to what works best for a particular person. Therefore, any specific diet and/or fueling strategy must be determined on an individual-basis.


Angela Naeth is a professional triathlete, cyclist, coach and partner at United Endurance Sports Coaching Academy (UESCA), a science-based endurance sports education company. UESCA educates and certifies running, ultrarunning and triathlon coaches (cycling coming soon!) worldwide on a 100% online platform.

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Hansen, Ernst & Emanuelsen, Anders & Gertsen, Robert & S, S. (2014). Improved Marathon Performance by In-Race Nutritional Strategy Intervention. International journal of sport nutrition and exercise metabolism. 24. 10.1123/ijsnem.2013-0130.

Rick Prince

Rick Prince

Founder/Director of United Endurance Sports Coaching Academy (UESCA).

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