Race Day Fueling

By Kara Dudley

With so many different types of fuel available these days, it can be overwhelming to know what to choose, how much and when to consume, and which options are suitable for your specific purposes. So I sat down with Starla Garcia of The Healthy Shine to chat about nutrition for runners on race day.


Fueling During the Race

Starla Garcia is an Olympic Marathon Trials qualifier and a dietician. The main ethos of her company, The Healthy Shine, is to help endurance athletes feel and fuel better. As a runner herself, she understands what it takes to educate oneself and get to know the body well enough to figure out what works best for you when fueling for races. I spoke with Starla about some basic nutrition questions that everyday runners may have around the topic.


How Much Fuel Do You Really Need During a Race?

The first thing to know is that when you’re looking at a nutrition label on any type of fuel, it’s important to look at the grams of carbohydrates, not the grams of sugar. The second thing to emphasize is that you are looking at how many grams of carbs you need per hour of running. This number is time on your feet-based, and is not dependent upon your pace per mile, although obviously correlated. Starla says everyone should consume a minimum of 30 grams of carbs hourly, all the way up to 90 grams of carbohydrate hourly if someone is able to tolerate that much. For example, if you’re looking to fuel for a 2-hour half marathon, that means you’ll need a minimum 60 grams of carbs total for the race and a max of 180 grams. This range is quite broad, which can be confusing for runners. When Starla is working with an athlete, she starts them at the lowest requirement and has them work their way up to what is effectively a fuel tolerance threshold. Contrary to what you may think, height and weight are not necessarily a factor when figuring out how many carbs per hour are right for you. In general, everyone should abide by these same simple rules, no matter who you are or how you are built.


Fuel Timing and Logistics

Starla says that you should never wait until you feel like taking fuel, you should begin taking your fuel early in the race, getting ahead of the actual need. Aim to take your gels (or fuel, generally) every 30 minutes. If you’re doing anything north of a 2 hour half marathon for example, you should take your gel at 30, 60, 90, and at the 2-hour mark to be safe. If you are taking a combination of liquid and gel fuel, you have to figure out a way to have that liquid on the course with -or offered to- you.



Liquid Fuel vs. Gels

Now that you know how many carbs you need per hour, it’s time to look at your products. If you’re using liquid fuel like Maurten Drink Mix 320, it has 79 grams of carbs in it. Per the instructions on the label, the suggestion is to drink it with about 18 ounces of water. If you want to use that as fuel, you have to make sure you can drink that full bottle of water without causing intestinal distress. To put it into perspective, if you’re running a four-hour marathon, you need to make sure you can drink a total of four of those bottles throughout the course of the race: one each hour. 

Aside from liquid fueling, another popular choice is gels. Most gels have 20-25 grams of carbohydrates in them. Reminder: you need at least 30 grams of carbs per hour, so if you think you can only tolerate one gel per hour, you can do a combination of gel and liquid fuel to get you to the right amount. Gu gels, for example, have about 22 grams of carbs per gel, so you’ll need more than one of those per hour or combine with liquid fuel to get you to at least 30 grams per hour. When it comes to liquids vs. gels, there really is no one option that works best, but an advantage of taking liquid fuel is that there typically will be electrolytes in the mix as well, although some gels also contain these. Starla encourages runners to go with whatever works for you and whatever you know you can be consistent with and tolerate best. “It’s a gray area and not a one-size-fits-all. I’ve coached 150-200 clients in the past year and I would say no two people have the exact same fueling strategy.” 




“Don’t wait; you should be grabbing fluid at the first table, especially if it’s a hot race”, says Starla. Taking in a cup at every hydration station on the course is ideal, but don’t put too much pressure on it. Over-drinking can also cause stomach cramps so you need to find a balance. If you miss a table or if you can’t get all the water from a cup into your mouth, it’s okay. “Research shows that even if you don’t want to take Gatorade on the course or if you don’t want to take a full water cup, you can simply do a mouth rinse. It may not get you all the benefits as it would if you were taking it in, but it will get you some increased energy and hydration.” A rinse is when you take water or a carb-filled drink into your mouth, swish it around, and then spit it out if you don’t have the tolerance to swallow it in the middle of a race, or if you haven’t practiced with it. If you are someone that’s having GI issues relating to your gels, you want to make sure you are taking in water at the same time as your gels. If you don’t, the gel can get stuck in your stomach and start fermenting, so it’s very important to get both in at the same time. One of the most important things is to remember to hydrate early on in the race even if you don’t feel like you need to. You don’t want to play catch-up on hydration as you near the end of a race and you’re starting to lose steam. Starla says, “It’s very hard to make up for hydration in a marathon during the last 10k.” 



Starla stresses the importance of using electrolytes regularly and paying attention to them in your fueling strategy. ”If you’re just using water on a race course and you’re not using liquid electrolytes, you need to make sure your gels have electrolytes in them”, she says. She suggests trying out gels that are higher in sodium or adding in salt tabs to their fueling strategy. Taking notes of each run on how you feel when taking in more sodium can be eye-opening in noticing how it can help you feel better on a training run or during the race. There’s not one suggested amount of sodium you should take in during a race, although most runners need somewhere between 500-1,000mg per hour. You can do a Sweat Rate calculation online by measuring your weight before and after a long run to see how much your body needs. 


Practice, practice, practice

When it comes to fueling, practice makes perfect. Trying out different types of fuel, different fueling strategies, and figuring out what works best for you, is a process. The more you can practice, the more your body will get used to fueling, and the greater chance you have of figuring out what works right for you. Starla urges, “Lean into the messiness of it. Some people want it to work out perfectly, but that’s not how it works. If you miss a cup on the course or get a little messy, that’s okay. All you have to do is stay calm and keep going.”

And most important of all, DO NOT experiment on race day! Visit Brooklyn Running Company in Park Slope, Williamsburg or online for all of your fueling needs.