Race Day Fueling Guide for the Beginner Triathlete

As committed triathletes we spend substantial amounts of money and time training our bodies to perform on race day. Months, even years, of blood, sweat and tears bring us to that finish line. However, one important and often overlooked element keeps many athletes from finishing on top: poor race day nutrition. 

The dreaded BONK. It’s real and it can ruin your race. Don’t let improper fuel be the thing that stops you dead in your tracks. 

What is Bonking?

Bonking is a condition of sudden fatigue and energy loss that is caused by depletion of glycogen stores in the liver and muscles. Studies have shown an immediate 14 percent drop in average power when stores are depleted. Simply put, you did not supplement enough fuel during the race and your body has used up all its reserves. 

The symptoms of bonking can vary. Commonly, athletes will feel extremely weak, tired and hungry. Some shake, sweat excessively and experience dizziness or light-headedness. Others report having heart palpitations. 

Avoiding the Bonk

Nutrition is often considered the fourth discipline of triathlon – it’s that important. A fueling strategy should focus on replenishing the three core elements that are depleted by your body during a race: water, electrolytes and carbohydrates. Each athlete needs to determine the right “recipe,” or mix, amount and mode to satisfy each element.

Here is what AgeGrouper Carley Gross (F25-29, WA) has to say about her nutrition and hydration strategy: “I have learned that solids are easier to take in on the bike while your core is in a fairly steady position and your heart rate is lower. On the run, more “liquid” solids (e.g., gels) are easier to digest because of the higher heart rate and the bouncing from the impact.”

One way to approach it is to create a “one-hour recipe” that can be repeated throughout a race or workout. The “recipe” might be unique to each discipline, but the concept is to have a repeatable plan as duration increases.

Fueling Recipes

Water: Most guidelines suggest drinking eight to ten ounces of water every 10 to 15 minutes of exercise. Athletes completing a full distance Ironman or ride in excess of five hours, must plan ahead since the bike cannot carry enough fluid. Make sure to plot out stops on training rides and pre plan water pick ups at aid stations on race day. Be sure to adjust water intake for excessive heat, humidity or if you are a heavy sweater. In those scenarios, plan to increase that recipe by a quarter or half a bottle to start. 

Carbohydrates: The average athlete needs nutrition to support 60 to 90 grams of carbohydrates per hour. Portable nutrition options are available in a variety of forms, from bars and blocks to liquids and gels. What you choose is up to you, but the more liquid it is, the easier it is to digest. Powdered mix options allow you to adjust all aspects of the fuel to your needs. 

It’s easiest to fuel on the bike since you are in a fixed, stable position and have storage options. To supplement nutrition on the run, most athletes prefer gels. Whatever brand you choose, remember to continue with your one-hour recipe. If your plan calls for 75 grams of carbs per hour, then make sure you have the right number of gels for your full run. Example: if you are using Hammer Gel, this would be three gels per hour. 

Protein: For longer course races or workouts over three hours, athletes need carbohydrates AND protein. In these scenarios, you can switch to a fuel that has protein added or include a protein bar, like Clif Bars, in your recipe. Remember to check the carbohydrate levels of any additional fuel to make sure you hit your hourly target. If you do choose bars over protein powders, make sure to chew it really well to avoid digestive issues. It’s a good idea to divide the bar into four pieces and eat one piece every 15 minutes. 

Electrolytes: These are absolutely imperative and athletes require them to keep muscles firing. They are depleted when you sweat and too great a loss can result in muscle cramping. The essential electrolytes are: sodium, potassium, magnesium, and calcium. Athletes should target 500 to 1000 mg of sodium per hour depending on size, sweat rate and temperature.

AgeGrouper Yale Glazer (M45-49, NJ) bonked due to lack of electrolytes. He thought he was taking in enough electrolytes but began to experience intense cramping. He had his sweat tested and discovered he was extremely low on electrolytes. Once he knew the actual numbers, he adjusted his nutrition accordingly and said it was a game changer. The results gleaned from a sweat test can then be used to personalize fluid and electrolyte replacement strategies.

You can add electrolytes in a number of ways. Some nutrition powders such as infinit Nutrition offer the ability to adjust individual elements of the mix and you can set your electrolytes to your desired amount. Another popular option are individual electrolyte supplements such as capsules and lickable salts such as Base Performance. 

Practice, Practice, Practice 

The adage “nothing new on race day” holds true for fueling. A race day nutrition plan needs to be practiced. Use training time to figure out the right combination for your stomach and energy needs. Rehearse all parts of the process.

AgeGrouper and triathlon coach Keith Putnam (M45-49, MA) said, “Racing fuel strategy is [determined] by trial and error, specific to what one can stomach and handle and still perform well. I always stick to what works for me in training sessions and I don’t stray from it on race day.”

Race Day Nutrition Plan

Depending on the distance of your race, sprint, Olympic, 70.3 half Ironman or full Ironman, you can adjust your one hour plan accordingly. This sample nutrition plan is for an Ironman 70.3, with a planned bike duration of three and a half hours and a planned run duration of two and a half hours. Temperature is in the low 70’s with low humidity. See our full infographic here.

Plan Ahead For Things To Go Wrong

Always have a back up plan. AgeGrouper Sabrina Somarribas (F30-34, NM) knows this all too well. “The most recent event that I bonked at was Ironman Arizona. A few miles into the ride, a huge part of my nutrition fell off of my bike. There were so many people that it was not safe to stop [and retrieve the nutrition]. It was a three loop bike course and by the second loop, I was already feeling the effects of not having my planned nutrition. Luckily, Gatorade Endurance was on the course and it is something that I have on race day and train with all the time. So I made sure to up my intake which helped my power through,” she said. Somarribas last piece of advice is, “Have your nutrition plan dialed in BEFORE race day, and nothing new on race day!”