How Much Fuel Do You Need During a Race?
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. In terms of fueling your run, you should calculate how many grams of carbs you need per hour of running.
This number depends on time on your feet, rather than pace per mile. You should consume a minimum of 30 grams of carbs hourly, all the way up to 90 grams of carbohydrate hourly if you can tolerate it.
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.
In general, everyone should abide by these same simple rules, no matter who you are or how you are built.
Fuel Timing and Logistics
You should begin taking your fuel early in the race, getting ahead of the actual need. Aim to take your gels (or fuel) 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're taking a combination of liquid and gel fuel, plan ahead to have a way to have that liquid on the course with -or offered to- you.
Liquid Fuel vs. Gels
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, 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 drink a total of four of those bottles throughout the course of the race: one each hour.
Aside from liquid fueling, the popular choice is gels. Most gels have 20-25 grams of carbohydrates in them, although many brands now offer high-carb gels. 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 combined 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.
Go with whatever works best you and whatever you know you can be consistent with.
Hydration
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. This is true for all races, but especially in warmer conditions. 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. It’s very hard to make up for hydration in a marathon during the last 10k.
You should be grabbing fluid at the first table. Taking in a cup at every hydration station on the course is ideal, but don’t put too much pressure on yourself if you miss one. Over-drinking may 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 take a full water cup, you can simply do a mouth rinse. A rinse is when you take water or a carb-filled drink into your mouth, swish it around, and then spit it out mid-race. It may not give you all the benefits, but it will give you some increased energy and hydration.
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.
Electrolytes
It's important to use electrolytes regularly and to pay attention to them in your fueling strategy.
If you’re just using water on a race course and you’re not using liquid electrolytes, look for gels with electrolytes, gels that are higher in sodium and/or salt tabs.
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. Most importantly, DO NOT experiment on race day.
Stock up on fuel and hydration supplies for your next race HERE