Nutrition / Food

Common Marathon Nutrition Mistakes and How to Avoid Them

Nutrition plays a bigger role in hitting that PR than you may realize.

When preparing for a half or full marathon, there’s more to training than just running. There are other important factors that come into play when preparing for a big race, and that includes nutrition. What you eat prior to, and on, race day is crucial in preparing you to perform your best. We asked two running coaches to help point out common marathon nutrition mistakes that they see people make, plus what to do instead.

Have you tried Aaptiv’s half marathon training program? 

How important is nutrition when it comes to running big races?

Running Coach Heather Tolford explains, “Nutrition is extremely important, not only for big races but [also for] the training that leads up to them. You can find the perfect pre-race meal, but if you have not consistently been fueling your body well, it’s not going to do much good.”

Ensuring that you are eating properly leading up to the race, and during your training, is paramount. Find a healthy balance of your macronutrients—that is, carbohydrates, protein, and healthy fats.

3 Common Marathon Nutrition Mistakes

1. Being Too Concerned With Losing Weight

We get it, weight loss is a common goal for many people. However, this can actually interfere with your goal of running a big race and cause you to undereat.

Even when you’re training, not eating enough can cause your body to enter starvation mode. This means that your body isn’t receiving the fuel it needs to recover from the running. Tolford highlights a common syndrome known as Female Athlete Triad. This “is a condition that occurs when one is overly concerned with maintaining a low body weight to be thinner, lighter, and faster. Eating disorders can develop, and [then] physical and mental health suffers,” she explains.

Remember that training for a big race puts your body under stress. You need to eat well enough to fuel it and prevent the risk of injury, such as stress fractures. Just remember, men are also susceptible to the same problems. Tolford recommends practicing moderation when it comes to empty-calorie snacks and treats. “A varied diet with lots of fruits and vegetables is always a good idea,” she adds.

2. Not Testing Out Energy Gels and Other Supplements

You’ve probably seen marathoners snack on energy gels during big races. It makes sense for you to do so as well, right? This is true, except, some people make the mistake of not testing these gels out beforehand.

“If you want to use the products you find at running shoe stores or race expos, it’s a good idea to test them before the big day on a long training run to see how your body responds,” says Tolford. There are also other supplements nowadays that can help. Tolford uses multivitamins and extra vitamin D and C. She even uses caffeine chewing gum to give herself energy while racing.

If you don’t test these products prior to the race, you might find that it doesn’t mix well with your stomach, which is the last thing that you’d want. So, make sure that you try and test a few different brands to see which ones work best for you.

3. Not eating the morning of the race

Maybe it’s the nerves, but one of the common marathon nutrition mistakes that people make is not eating before the race. Coach Sean Fortune, USATF level II coach and former NCAA distance coach, 3x New York Road Runners race winner, says, “In order to run to your potential on the day, you have to be adequately fueled for the demands and distance of the race— 5K to marathon, hilly, or flat.”

There are some worries about eating too soon before a race in case of a stitch, so Tolford says, “A pre-race meal should be tested well in advance of a big race. Practice different foods before hard training runs, or other races leading up to your big event.” Practicing in advance is crucial. This is because what you eat and how much you eat greatly depends on what kind of race you’re participating in.

Pick a meal that’s easily digestible.

“For a 5K, a small bowl of oatmeal with honey and bananas works well for me with a glass of water. For a marathon, I’ll have the same and then a granola bar or two a little bit later,” Fortune explains. He also makes sure that he leaves “enough time to digest the food so it’s accessible and not diverting precious blood to my stomach to break down and process the food instead of going to my legs where it’s needed. A good rule of thumb is to finish your meal of easily digestible carbs two hours before the race.”

If you’re finding it hard to eat food before the race, you’re not alone. “I had to practice eating something in the morning before races. For years, I was guilty of not really being a breakfast person,” admits Toldford. But, it’s important that you do. “Research has shown that after fasting during the night when you are sleeping, your cortisol levels can rise. Without something in you to make your body not think that it’s starving, you could be at greater risk for injury when you go out to pound the pavement.” She suggests trying to get down a bagel, banana, or even yogurt.

What to Eat in the Days Leading Up to the Race

It isn’t just what you eat on the big race day that’s important. It’s also crucial to make sure that you’re eating properly in the days leading up to the race.

Carb loading is a thing, and you certainly need to increase the proportion of carbohydrates in the days before a long distance event to ensure that you have the maximum level of glycogen in your muscles,” says Tolford. “But, I caution runners not to go crazy with the carbs the day before the race.” Instead, “Eat a big meal a couple of days before and then eat more normal portions the day before to avoid stomach problems during the race. Don’t forget to drink lots of water. You want to be well hydrated!”

Fortune agrees. He enjoys digestible carbs the night before the race (as well as the morning of the race). “Oatmeal, rice, and vegetables with a little protein—everyone should experiment to see what works for them.”

What To Eat After the Race

Fortune suggests a similar meal after the big finish, as well. However, he advises upping your protein intake for the post-race meal.

Tolford also adds, “You will typically be given a bagel or piece of fruit once you cross the finish line at many races. Enjoy the snack, but then make sure [that] you have a good solid meal as soon as you can. Have something you really enjoy and celebrate your finish!

Just remember, the best way to avoid common marathon nutrition mistakes is to plan. Not only is planning what to eat important, but also when and how much to eat. Eating too little can leave you with hunger pains while eating too much can give you a stitch.

Fortune says, “I learned by trial and error what worked for me. And that wasn’t always the same as for other runners. Getting the right food and calorie amount for you and the demands of the race and the timing down is the tricky part.”

So, find out what works for you. It will leave you feeling stronger and faster for your big day. And, of course, don’t forget to hydrate, hydrate, hydrate! “Make sure each and every day [that] you drink enough water,” Fortune adds. “It’s an everyday thing.”

Food Nutrition


Welcome to the guidebook to your healthiest life. Aaptiv delivers the highest quality fitness and health information from personal trainers and industry experts. Subscribe now for a weekly dose of inspiration and education.

I would like to receive weekly fitness articles and inspiration from Aaptiv Magazine.

Please click the checkbox to subscribe.