Carbs, electrolytes, and how to perfect race-day nutrition during training.

Learning to set up your nutrition plan can be one of the most difficult things you do as you prepare for race day. It’s also one of the most important. There are so many things to consider. How many Carbohydrates and electrolytes do you need per hour? Should you worry about Caffeine? Will liquids, solids, or gels work best for you? How do you carry everything on the bike and run? Should you use special needs?

Figuring out where to start is often the hardest part, so I wrote a quick overview of my own approach to fueling for races, and I put together a step-by-step guide explaining how I dialed my nutritional needs to help you dial your own.

How I fuel with First Endurance

First Endurance has 3 main carbohydrate/electrolyte methods: EFS-PRO, which has a blend of fast burning complex and simple carbohydrates and higher in electrolytes, EFS, which is a higher carbohydrate and lower electrolyte blend, and Liquid Shot, the fast fuel and anti-cramping emergency option.

My “base” plan that I used in relatively benign weather conditions is about a 50/50 mix of EFS-PRO and EFS as well as a Liquid Shot every 90 minutes on the bike. If the weather is hotter and more humid, I’ll take a Liquid shot every hour and rely more on EFS-PRO in my bottles since it is higher in electrolytes. In Kona-like conditions I’ll bump Liquid Shot frequency up to every 45 minutes!

For cooler races, I’ll switch and rely more on EFS as my sweat rate will be much lower. That is the great thing about the way these First Endurance products have been designed – they’re scaleable, so it is quite easy to alter the amounts you take of each to be able to hit your desired carbohydrate and electrolyte levels while still maintaining optimal osmolality in the gut for proper digestion and fewer catastrophic bowel issues.

Of course, what I’ve just described is my fueling regimen, unique to my body, my needs, and my abilities. Yours will be different. I’ve refined my approach through testing, training, and – occasionally – getting it wrong. Ideally, you’ll only get it wrong on training days, though, and those days will ensure you get it right on race day.

Training to fuel

One thing I always stress with the athletes I coach is the need to develop a plan that is set up to meet the specific demands of the course, the event, and your body. In order to do this properly, you need to practice your plan over and over again on your bigger workout days.

The goal as you develop your plan isn’t to necessarily get through your workouts feeling good, because long-course triathletes aren’t covering the entire race distance at race intensity until race day. If you only fuel to finish the workout, then you won’t be prepared to fuel for the entire event on race day.

In training, instead of just fueling on the bike to finish the training ride, you want to practice fueling on the bike as though you have a long run in front of you, like you will on race day. This helps ensure you know what you need and what your limits are, which can be just as important. Trying to run with your sports nutrition trying to exit both ends of you is never fun – although it is one way to ensure the crowd notices you!

Here are a few tips I’ve developed through my own practice to help you dial in your fueling plan with the First Endurance suite of products.

Track sodium loss

Step one is to figure out your sodium loss per pound of sweat. This can be difficult to do on your own, but there are a few devices on the market that will help you figure this out, and there are a number of bike shops that have a unit that can help you test to get a good idea of where things are at. Of course, this number will change slightly depending on your diet and sweat rate, but it is a starting point.

Track sweat rate

Next you want to try to figure out roughly what your sweat rate will be in the conditions of the race. If the environment you are training in is similar to the race, then this is pretty easy. (If it’s not, then you may need to try to set up your indoor training environment to try to mimic the environment.)

Workout for an hour or two, weigh yourself pre- and post-workout, then subtract the weight of the fluids you consumed. Sometimes the simple solutions are still the best!

Track calories burned

Finally, you need to figure out the calories per hour you need to/can consume! This requires a good deal of practice, and I suggest planning to use all of your big workouts leading into race day to work to dial this in. I’d much rather have something go wrong in a workout than on race day, so be willing to push the limits, experiment here, and also learn to listen to the body. For more details on calculating carb consumption – and for training your gut to handle increased carb loads while exercising – check out Dr. Luke Bucci’s all-about-carbs blog post.


Once these steps are complete, you can work on dialing in the plan with the specific products you intend to use as well as the logistics of carrying/accessing them on race day.

In closing, I’ll remind you of the cliché “practice makes perfect.” I’m continually amazed by the people who will spend $15,000 on their bike, then make a number of $1,000 upgrades to save a watt on race day, but then say that it’s too expensive to practice with the nutrition they intend to use on race day. I’d argue that a proper nutrition plan will give you a much bigger return on your investment!

April 20, 2023 — Matt Hanson
Tags: coaching

Leave a comment

Please note: comments must be approved before they are published.

Did you find this post interesting and valuable or was it a waste of your time? Do you have a topic you’d like us to cover or a question you’d like answered? If so, leave a comment below and we'll get back to you right away.

    1 out of ...