Just In: What to Eat When Training for a Marathon

Updated 06/19/19

Jess Barron is the vice president and general manager of Livestrong.com. A longtime foodie, she particularly loves heirloom tomatoes, fresh figs with burrata cheese, and anything with pumpkin in it. Her love for food fuels her desire to exercise daily. In this month's column, she shares her recent experience training for the famous Boston Marathon.

What to Eat When Training for a Marathon
Calla in Motion

This past April, I accomplished a bucket-list goal that a limited number of competitive runners are able to achieve—I crossed the Boston Marathon finish line. Thanks to an invitation from the Clif Bar, I was able to join the brand's team for this historic run. The 2017 race marks the 50th anniversary of the first time a female runner registered for and completed the Boston Marathon: Kathrine Switzer in 1967. In the 1960s, women were told they were too fragile to run marathon distances, so the race was for male runners only.

Not only that, but rules at that time forbade women from competing in races longer than a mile and a half.

Switzer, who was 20 years old in 1967, got into the race by registering under her gender-neutral initials K.V. Switzer. The officials tried to eject her from the race when they realized she was a woman, but fortunately, she was able to outrun them (with some help from her friends, including her boyfriend and running coach) and go on to complete the race. Today, the percentage of female marathoners is getting much closer to 50%. Inspired to give it a try one day? Ahead, I share my timeline in preparation for this historic run, along with what to eat when training for a marathon. It's a commitment but totally worth the effort.

Week 1: Get It on the Calendar

If you're inspired to run a marathon, first choose your marathon (here are 22 of the world’s best marathons for inspiration), and officially register. Keep in mind that for the Boston Marathon, you need to have a qualifying time from a previous certified marathon distance race. Next, you'll need a good training plan. My training took two and a half months, but most people aim for three or four months. 

Another important aspect of your training is motivation. Think of why you want to train for and run this race. It could be to get fit, to lose some weight, or as a dedication to a cause or person. I dedicated my Boston Marathon to my brother James who died 15 years earlier to suicide, and I made it a goal of mine to raise $5000 in his name for the American Foundation for Suicide Prevention. My brother and I grew up in the Boston area, in a town right next to Hopkinton where the marathon starts. It’s helpful to have someone in mind when you race to help you through those points where you might want to give up and stop.


You will also need a great eating plan because, trust me, when you're running 30 to 45 miles per week, there will be many times when you're hungry—incredibly hungry! You need to fuel your body for training and recovery. Luckily, I was able to get some marathon training nutrition advice from Clif Bar registered dietitian Tara DelloIacono-Thies.

11 to 16 Weeks Before the Marathon

In the first weeks of your marathon training (when your mileage is lower than 20 to 25 total miles per week), it's recommended you eat higher protein and lower carbs since your body isn't demanding as much carbohydrate during this time of lower mileage. According to the plan DelloIacono-Thies provided me, an endurance athlete's protein needs are greater than the U.S. Recommended Dietary Allowance for protein, which is only a modest 0.8 grams of protein per kilogram of body weight.

The actual protein needs of endurance athletes have been estimated to be in the range of 1 to 1.6g/kg of body weight per day. This means that a 125-pound woman training for a marathon would want to consume between 56 and 90 grams of protein per day. I aimed for at least 20 grams of protein at each meal and 5 to 10 additional grams in my snacks. After a run or other vigorous exercise, it's essential to eat something within the 30- to 45-minute "recovery window" immediately afterward, because during this time, your blood is still pumping faster than normal, which enables your body to replenish glycogen stores faster and stimulates the repair of muscles damaged during exercise.

One of my favorite post-run snacks was a sliced organic apple coated in Nuttzo organic nut and seed butter. I also loved organic sprouted-grain toast coated with nut butter and sliced bananas. In addition, I made my own two-minute gluten-free blueberry microwave muffins and protein berry oatmeal. I use Sun Warrior Vanilla Protein powder because it's made from organic pea protein. (You can incorporate protein powder to kick up the protein in a lot of different dishes and snacks from hummus to soup.) Before my early morning runs, I would eat an orange or a banana to get something into my stomach for an energy boost.

BONUS: How to Get Enough Protein

I don't eat meat, so I wanted to give some food suggestions for vegetarian runners to make sure they're consuming enough protein. Two of my (almost) daily go-to sources were either a Sun Warrior vegan protein shake or a Clif Builder's Protein Bar, each of which contains 20 grams of protein per serving. I would often consume these post-run. For other high-protein meals and snacks, I'd eat eggs (two eggs contain 12 grams of protein), Siggi's Icelandic Skyr whole-milk yogurt (12 grams of protein), organic cottage cheese, organic sprouted tofu, and organic hummus.

3 to 10 Weeks Before the Marathon

When your weekend distance training runs become longer than 8 to 10 miles, you'll want to start carrying water in a hydration pack and consuming food during your run. I don't enjoy the consistency of eating gels and goos, so I was thrilled when DelloIacono-Thies introduced me to Clif Shot Bloks. They're just like gummy bears in squares but are USDA organic and do not contain gelatin, so they're vegan-friendly, too. The sodium content helps you retain key hydration.

The recommendation is to consume 30 to 60 grams of carbs per hour while training. For me, this meant one to two Shot Bloks per hour. DelloIacono-Thies's nutrition plan makes an important point: "Long training runs are your best opportunity to practice how and what you will eat and drink on your race day—use long runs to figure out which foods and sports nutrition products you will use during your race, when you will consume them, and how you will carry them."

Keep track of which foods and drinks feel good in your stomach while running and which don't. This will prevent any mishaps on race day.

When your total weekly training mileage increases to above 30 miles per week, you'll want to eat more carbohydrates. During this time, I stuck with all of my original foods, but I added in a lot more fruits and grains. I usually ate at least three to four pieces of fruit per day: bananas, apples, and oranges. I ate oatmeal, which I made into protein oatmeal by adding a tablespoon of protein powder, frozen blueberries, honey, and a tablespoon of nut butter. I also ate the new Clif Bars that are filled with nut butter.

Last 2 Weeks Before the Marathon

Courtesy of Matt Trappe

Two weeks before your marathon, you begin tapering your training mileage. During this time, DelloIacono-Thies advises decreasing the portion sizes of your meals and snacks to make sure you don't overdo it (especially since you are running fewer miles in these last weeks). Believe it or not, there is no need to "carb load" the night before the race if you maintain proper levels throughout the week prior to your race.

The Day of the Marathon

On the morning of your marathon, eat a bowl of oatmeal mixed with banana slices and salted peanut butter before heading to the race. If you don't have time for oatmeal, eat a protein bar that your body is accustomed to consuming. Also, have some coffee, if that is part of your regular routine. On the ride or walk to the start line, keep consuming electrolyte drink and water as well as have another snack of salted almonds or banana.

During the race, it's essential to keep your energy up and consistent. If you forget to take in fuel, hydration, and electrolytes or salt at regular intervals during your race, you could get too exhausted by mile 18, which is typically the toughest part of any race. You could also risk getting dehydrated.

Pack your fuel/snacks to bring with you, and carry them in your pockets or hydration pack. DelloIacono-Thies recommends consuming 30 to 90 grams of carbs per hour while running your marathon. During the Boston Marathon, I ate two to four Clif Bloks every hour. It’s essential to eat them with water. A tip: You can set an alarm on your phone to go off at 30-minute intervals to remind you to eat and hydrate. The Boston Marathon has a half-mile-long hill at mile 20 called Heartbreak Hill. It is a challenging physical and mental feat to push yourself up against it at that point in the race.

I will always attribute getting up Heartbreak Hill and completing my marathon to the perfect trifecta of 1) the photo of my brother that I was carrying, 2) the positive energy from the Boston Marathon spectators cheering, and 3) the essential energy boost I got from eating the Clif Energy Gel at mile 18. So keep those in mind as a secret weapon!

When You Finish the Marathon

Courtesy of Matt Trappe

I was so dazed from the heat and exhaustion at the end of the Boston Marathon that after I crossed the finish line, I nearly missed my opportunity to get a medal. One of the professional race photographers saw me in the post-finish-line chute without a medal around my neck, and he said, "You don't have a medal! Go back and get one!" I had walked past all the people handing out medals and didn't even realize it. When I walked backward against the flow of runners a few hundred feet and saw the people handing out medals, they asked me, "Didn't you already get one?!" And when I told them no, they trusted me and handed one to me.

I will always be so thankful that I turned back to get my medal.

After the marathon, DelloIacono-Thies advises runners to consume a meal containing 60 to 95 grams of carbs and 10 to 20 grams of protein within two hours of completing the marathon. She recommends you drink chocolate milk and eat a turkey sandwich. With my medal in hand, I walked a few blocks and found my husband, my mom, and my dad, and they took me out to a post-race dinner where I ate a whole flatbread pizza and a whole basket of warm pretzel bites with beer cheese. I also enjoyed a celebratory bourbon cocktail.

Here's to your marathon! Contact me on Twitter (@jessdandy) or Instagram (@jessbfoodie) if you have any marathon training questions, or post them in the comment section below.

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