First-time marathoners, if your training program is overwhelming you (and, if you’re anything like I was during training for my first 26.2, it is), I’m here to make one particular part of your marathon journey significantly less complicated and confusing: fuel. Specifically how to go about it when your runs get long.
When training for a marathon, people tend to focus on (and stress about) the obvious: running long and often. However, an overlooked—yet super important—component of crossing the finish line and staying healthy throughout your entire training cycle is midrun nutrition.
For some, it might seem simple: Can’t I just chomp down on half a banana during a long run? For others, it might be confusing: Is eating lots of sugar OK? What about GI issues, cramping, or bloating?
Use this as your guide to eating and drinking on the run, which is necessary for anyone training for a marathon. From gels to chews, hydration tabs to caffeine, here’s the deal, not only with what to consume while running, but why it’s one of the most important things to think about when it comes to crossing the finish line.
Note: This is specifically for athletes tackling a road marathon. Trail running—which typically equates to slower running with more elevation variation—usually means stomachs can handle different types of food and therefore follows a different race-day nutrition plan.
Midrun fueling—Why bother?
Before we dive into the what, let’s look at the why. Why the heck is it important to eat during a run? What’s going on inside our bodies?
“We only have so much glycogen stored, which is what the body uses for energy while running,” explains Kelly Hogan, M.S., R.D., who works with athletes and has run 11 marathons herself. “We can use up all of those stores in about two hours. That’s when people start feeling like they’re going to bonk.” (The bonk, by the way, is the point at which your body, brain, or both feel like they can't take another step and it typically happens to endurance athletes especially when they're not properly fueled.)
It’s important to start fueling well before our bodies are close to using up all our glycogen stores. For most runners, that’s 30 to 45 minutes into a long run. Still, every body is different, and it’s essential to practice fueling during your training runs so you don’t introduce something your stomach can’t handle on race day.
“The biggest mistake I see—by far—is people doing something different in their race versus training,” says Douglas Casa, Ph.D., professor of kinesiology at the University of Connecticut. He, too, has worked with athletes for years and is an avid trail runner. He continues: “Regardless of exact amounts—those are nitpicky things—a lot of ranges [for food and drink consumption] can be successful. Instead, it’s a matter of asking: Is your body ready for it? The crux of it is you have to rehearse.”
OK, I’m ready for rehearsal! Can I grab a Snickers?
Actually, yes! (Well, OK, maybe a mini Snickers.) The main rule of thumb for midrun food is to find something that will give you energy and is easy to digest, and kid-sized candy is actually something that many runners stick in their pockets before heading out the door. As a rule, the body needs fast-absorbing carbohydrates that will boost blood glucose levels and send sugars through the bloodstream and into the muscles.
It doesn’t have to be a candy bar, though. Most runners get their quick-digesting carbs from gel packets or sports chews (GU, Hammer, and Clif are great options), which are easy to slurp down while running. Other examples of easy-to-eat simple sugars include sports beans, fruit drops, and even thin, cookielike waffles. (In my opinion the Honey Stinger honey waffle will get anyone out the door for a long run.) You can also get sugars from a sports drink, like Gatorade or Maurten, a drink mix that's an alternative to mainstream sports drinks and that's used by many elite runners.
“I think GU and gels are getting knocked since they are processed sugar,” explains Hogan. “But it’s only sugar for a reason—we need it for running.”
That said, not everyone can tolerate the same types of foods. “It’s important to test different foods to see what your body can handle,” Hogan reiterates. If highly processed foods aren’t your thing, she recommends trying a less processed option, like dried fruit or pretzels. My personal go-to is Spring Energy gels, which use whole ingredients like rice, banana, and peanut butter, blended into a gel-like substance. As long as you can get over the fact is has the consistency of baby food, you’ll be set.
For coffee lovers, there are caffeinated fuel options! Certain energy gels also include caffeine; the amount typically ranges from 20 to 40 milligrams, though some are packed with up to 150 mg. (In comparison, a grande Starbucks coffee has 100 to 120 mg of caffeine.) While caffeine can give runners a nice jolt of energy, it isn’t a necessary additive to your fueling regimen. “Caffeine intake during the run is meant to give a bit of an energy boost, but is different in how it affects various individuals,” Hogan explains. “Starting out at the lower end of caffeine—that’s 20 to 30 mg—is a good idea to see how the body reacts, as opposed to going for a gel with 75 to 100 mg of caffeine right at the start.” Hogan also suggests alternating between noncaffeinated and caffeinated gels just to stay on the safe side. Unlike sugar in gels, caffeine stays in our system longer. “We don’t want to be up all night after a long run or race, or having lingering feelings of the jitters, nerves, or anxiety.”
So, what should I avoid?
As far as what should be on the “do not eat” list, foods that are too heavy on protein and fat might do more harm than help.
“Save the protein for after the race," advises Hogan. “Calories from protein and fat won’t do much for your body. Fat especially can be the culprit of GI issues since we digest it the slowest.” Fiber could cause tummy trouble, too, since it also takes a toll on our digestive system.
For this reason, avoid foods like leafy greens, cruciferous vegetables (like broccoli and cabbage), and beans, along with red meats, fish, and cheese 12 hours before a long run or your race. Aim to have your prerace meal be about 75 percent carbohydrates, and stick to mainly carb consumption when you’re out on the course.
When should I eat? And also, how much should I eat?
Now that you know what to eat, when should you eat it? And how much is enough?
“The general idea is to start with consuming 30 to 60 grams of carbohydrates per hour,” says Hogan, which is the range our bodies can absorb glucose and varies slightly depending on how big you are, how fast you’re running, and how quickly you're burning through your calories. This amount of carbs per hour could include two 1-ounce bags of sport beans or two energy gels. “For most people, start to fuel 30 to 45 minutes into the run to get a head start on your glycogen storage.”
If two gels seem too hard to stomach, go for a combo: a mixture of chews, beans, or a gel will also do the trick. Keep in mind that sports drinks, though they're liquid, provide carbs, so you should factor that in when calculating your carb intake.
What's the deal with water?
Hydration is another critical component of your fueling strategy. Casa recommends carrying water with you—whether in a hydration pack, fuel belt, or handheld water bottle—so you can sip water throughout your run versus relying on aid stations, where people tend to gather to chug down fluids.
“This allows you to drink whenever you want and you avoid the rush of people at the aid stations,” he explains. (I will vouch for him here; while aid stations volunteers are super helpful, and the tables are always stocked with food and drink, they sometimes can get overwhelmingly crowded.)
Just like calorie consumption, there isn’t a one-size-fits-all amount when it comes to hydration. In general, your fluid intake should depend on your sweat rate, which is the amount of fluid you’re losing through sweat while exerting energy. Sweat rates vary depending on body size, activity intensity, and environmental conditions. For example, a larger person who is running 7-minute miles in 80-degree heat might need 2 liters of water an hour, versus a smaller person running 10-minute miles in mild conditions might suffice with a half liter.
Luckily, there’s a foolproof method for figuring out your sweat rate at home. Simply urinate, get naked, and weigh yourself in kilograms. Then head out on an hour-long run without consuming any water or food. Once you return, weigh yourself again. The difference will show you how many liters you sweat per hour. For example, if you weighed 60 kg before your run and 59 kg after, you sweated 1 liter per hour. This is the amount of water you should drink every 60 minutes. That said, you definitely don’t have to use this strategy. The trial-and-error method is just fine, too.
Calculating this sweat rate not only ensures you’re drinking enough but protects you from drinking too much.
“Pay attention if your body feels super full and you have a sloshy feeling in your stomach,” Hogan says. “This is one of the first warning signs of hyponatremia.”
Hyponatremia is a rare and dangerous medical condition that occurs when the concentration of sodium in your blood is abnormally low, which can happen if you drink too much water. While Hogan notes that hyponatremia is rare, it’s important to understand the warning signs. When you’re drinking, make sure your body feels satisfied but not overly full. If you feel extra bloated and start to become dizzy and disoriented, it’s critical you pump the breaks and get medical attention. Casa echoes this sentiment; if you’re aiming for a five-hour finish time and the race conditions are mild, it’s easy to overcompensate and think you need to be drinking a ton. Figuring out your sweat rate will give you peace of mind and more confidence when you toe the line, because of course, you still do need to hydrate adequately throughout the race to avoid dehydration, another dangerous (and more common) condition.
A guideline I like to follow is taking in 3 or 4 long sips of water every 15 or so minutes. On long runs, I’ll often fill my hydration pack with water that has a hydration tab mixed in it, called Nuun, which has added electrolytes, like sodium. Electrolytes are minerals that keep our systems functioning and, in the case of extensive sweat loss, will need to be replenished. It’s easy to add electrolytes—especially sodium—into your running diet; sipping on Gatorade, using Nuun tablets, or even munching on some pretzels will help restore the electrolytes that become depleted in the body.
“Sodium is extremely helpful in a beverage,” notes Casa. “It keeps the thirst mechanism on longer so you replace the fluids you need, conserve urine, and replenish the sodium you’re losing in sweat.” Everyone loses different levels of sodium in their sweat. Casa says a gram of sodium per liter is generally a good amount, which is the serving size found in products like Nuun and Gatorade Endurance Formula.
Now that you know the why, what, and when of eating on the run, here are some handy tips to keep in your (running shorts) back pocket.
1. Practice your fueling and hydration strategy until you perfect it
Let’s be real. No matter what the guidelines say, it’s nearly impossible for anyone besides you to know exactly what your body needs. That’s why practicing your fueling techniques on long runs prior to your race is so, so important. Figure out what your stomach can handle, what you personally like to eat and drink, and how it makes you feel. Use your long runs as trial workouts before your marathon. You don’t want to introduce anything new to your body when you toe the line, so get it used to the exact things you’ll consume.
2. Find out what will be provided on the course and after you finish.
Check the race website or contact the race host to see what food and drink will be available on the course. Many races supply water, Gatorade, and gels at different aid stations, but it really depends on the race. See if there’s a course map that tells you what’s available and where, so you can figure out what you need to carry with you versus what you can snag at the aid table.
3. Figure out how to carry your fuel.
Speaking of carrying fuel, it’s important to decide how you’re going to do that. Embarrassingly, for my first marathon I stuffed a few Gu gels in my sports bra, and after the race, I had cuts on my breasts from the hard plastic poking into my skin. Nowadays, there is running apparel with plenty of pocket options for small snacks, or you can choose to run with a hydration belt, handheld water bottle, or even a hydration pack. As Casa reminded me, carrying water and sipping it throughout has its benefits, and most packs are designed so you don’t even feel like you’re carrying extra weight.
4. Get comfortable with the idea that you really do need more carbs (usually in the form of sugar), to keep running long and hard.
The most important takeaway is simply that your body needs calories while you’re running long, especially if you're a new marathoner, which means it's your first time putting your body through a 26.2-mile race. Trying to run long with too few calories will likely make it tough (if not miserable) to finish the race without bonking. Plus, it will make it much harder to recover from the race, says Hogan.
For your first marathon, remember what Hogan told me: “Carbohydrates are your friend, sugar is your friend.” Don’t be afraid to consume sugar on the course, drink moderate amounts of fluids throughout, and pay attention to how your body reacts to it. Although staying fueled while running can get complex, it really comes down to tuning into your energy levels, checking in on your stomach, and getting used to the types of foods your body really craves while hitting the pavement. Whether that’s an energy gel, handful of raisins, or Snickers bar is up to you and your gut.