Marathon Training Diet + What I Eat in a Day

When you train for a marathon, you have a training plan, right? But do you have a plan for your diet? You can’t overlook nutrition, especially as the miles ramp up!

When training for a marathon, you may be running 40-80 miles a week on on top of a full-time job, full-time parenting, or both! You may be so focused on getting in the miles that you just grab whatever food is convenient and quick throughout the day. But focusing on your marathon training diet is just as important as logging the miles. And while I’m not training for a marathon right now, I many people are planning to do fall races, so I wanted to share some tips on fueling since training and race day nutrition is SO important.

Marathon Training Diet + What I Eat in a Day

When I’m logging serious miles, I often get asked what I eat in a day. And, to be honest, it’s not very exciting. When I was training for the 2018 Boston Marathon and then again, for the 2019 race, I ate pretty simply for a few reasons:

Convenience

I don’t mind eating the same thing over and over because it’s less thinking. 🙂 Plus, when I was training in 2019, I was working a LOT on top of a pretty intense training schedule, so convenience was key!

Time

It’s faster to eat simple things! Tossing things with olive oil, salt and pepper — which is how I serve basically everything — is faster than following a recipe.

Marathon Training Nutrition

When my mileage ramps up, my stomach often gets more sensitive. Heavily processed carbs (e.g. white bread, crackers, etc.) and dairy wreck me. As a result I tend to eat the same things that I know work for me.

When you’re training for a marathon, it’s easy to overlook your diet and sleep. But both are crucial to your success. Plus, most of us know too well that awful feeling on a run when your gut gets MAD and you immediately think back to what you ate the night before. And stomach aches aside, how you fuel your body contributes to how you perform. It can contribute in a positive manner or undermine your running. And wouldn’t you rather have your food add to your success?

You simply can’t ignore nutrition when you’re going after a PR or tackling a hard distance.

While I use a training plan or a coach for my marathon training, I don’t use a true “meal plan”. I just eat things I know will make me feel great, agree with my stomach, and keep me full. Oh, and I eat LOTS of carbs and I eat all day long (especially when running and breastfeeding!). But if you really don’t know much about nutrition, it may be worth working with a registered dietician who specializes in athletic performance to help you identify where you may need to make some adjustments.

InsideTracker is a great tool to help you identify gaps in your nutrition as well. I also have a lesson in my running course about what to eat before, during and after a run.

What to Eat When Training for a Marathon

What a marathon runner eats will differ from person to person. We all have different preferences, mileage levels, goals, body weight, and food sensitivities (or lack there of). What’s consistent is that carbs are super important for all runners. A good rule of thumb is to aim for 4 grams of carbohydrate for every pound of body weight. If you like to look at percentages, endurance athletes (which is most runners who run 4+ times a week) should get 55-65% of their calories from carbs. Some elite runners have shared that they even get 70% or more of their calories from carbs. The general consensus for runners among those who study the data around marathon running is that low carb diets do NOT work.

Some of my favorite resources for runners dietary needs are linked below:

• Run Fast Eat Slow
• Run Fast Cook Fast Eat Slow
• Cook Eat Run
• Nutrition Timing for Peak Performance

The first three have recipes, as well as information about the various aspects critical to runners’ diets. The last one talks about the importance of timing certain macronutrients for performance and recovery. This post about the importance of carbs is also a must read.

A simple thing to analyze is simply paying attention to any neglected food groups. Do you eat a LOT of protein but not many carbs, e.g. keto? If you’re relying solely on vegetarian protein sources, make sure you are getting enough protein to help your muscles rebuild and recover.

Or maybe you love fat (e.g. nuts and nut butters), but neglect protein.  Ask yourself if the fats you’re eating are healthy fats (from nuts and healthy oils) or if they are coming from trans fats and fried foods. Or maybe you get 99% of your calories from carbs? And what types of carbs are you eating? Are they mostly processed (e.g. crackers, pretzels, cereal) or do you have some non-processed carbs as well (e.g. potatoes, fruit, rice, whole-grain bread, etc.)

There is definitely a time and place for processed carbs (the Nutrient Timing book explains that well) but you should also make sure you focus on getting high-quality, slow digesting carbs too!

A Typical Day of Snacks and Meals For Marathon Training

Pre-run

I’ll eat a couple energy balls or a couple pieces of toast with honey. Other times I’ll do a sliced banana with peanut butter. And I also have a water with LMNT, my favorite electrolytes. If I’m doing toast, I like Dave’s Killer Bread, which I get at Costco but most stores carry it. During my run, I’ll also sip on LMNT and possibly have an energy gel if it’s a long run.

Breakfast

My breakfast is never anything really glamorous – just some kind of eggs and toast, steel cut oats with peanut butter and berries, a bagel with dairy free cream cheese or a smoothie bowl. Sometimes I’ll break my breakfast into two meals about an hour apart if I really can’t stomach eating too much right after training sessions. (I almost always run in the morning.)

But, I do make sure to have some toast or a small bowl of oatmeal within 30 minutes of finish to help replenish my glycogen stores. Then, I’ll eat another round of breakfast about an hour later. This apple oatmeal bake is a go-to once it cools down since I can make a batch on Sunday and eat it all week.

Lunch

I make lunch at home most days, usually a salad with protein, like chicken or tuna, with a side of toast and/or an apple. I don’t spend a ton of time on putting together the salad, since I usually have meat already grilled or I’m just popping open a can of tuna or salmon. If I’m craving a sandwich or wrap, I’ll stuff it with deli turkey, cucumbers, avocado and lettuce. Other times I make an open-face tuna sandwich.

Dinner

Most of our dinners are pretty simple. It’s sort of protein (beef, chicken, salmon or lentils) + sweet potatoes or brown rice + whatever veggies are in season. I don’t love pasta but Tommy does so we typically have a pasta-based meal at least once a week as well.

Snacks

I have 3-5 snacks a day, sometimes more. I eat when I’m hungry! So I have a snack between breakfast and lunch, and 2-3 snacks between lunch and dinner. And sometimes I eat a snack right before bed. My go-to snacks include:

• trail mix
• apple or banana with peanut butter
• hard boiled eggs with a piece of fruit
• RX Bars
• spoonfuls of nut butters (usually with dark chocolate!)
• homemade muffins (I keep a bag in the freezer)
• homemade energy balls – this recipe is my all-time favorite, followed closely by this s’more coffee one!
• toast with peanut butter

And at least two of my snacks involve toast. Toast is my favorite food and it’s a great way to get in some carbs without leaving me feeling overly full. Typically, one of my afternoon snacks is buttered toast with a handful of trail mix and my evening snack is toast with peanut butter. (I like Dave’s Killer Bread, Ezekiel sprouted english muffins or Silver Hills sprouted bread. Or homemade wheat bread if I have that around!)

I can eat toast 20 minutes before a run but anything heavier than that, I need about 30 minutes for food to digest!

Gaining weight during marathon training

It’s not uncommon for runners to gain weight while training for a marathon. Sometimes it’s because they overestimate how many calories they burned and underestimate how much they are eating. The “I earned this!” mindset can also lead to not so great choices. Yes, eat dessert and enjoy your favorite foods. But training for a marathon isn’t a free pass to eat anything you want all time.

Conversely, many marathon runners don’t eat enough during training — I’ve run into this issue myself. That will make your runs miserable, prevent you from recovering well, and also may lead to metabolic issues that could impact your weight. And for females, underfueling can lead to the female athlete triad which has many more serious implications than a number on the scale.

I’m not a registered dietician so if you think you’re dealing with a calorie imbalance, work with a registered dietitian to identify and address the issue.

Dealing with food sensitivities 

One of the biggest things to figure out in marathon training is what foods work for you and what don’t. In the last few weeks leading up to race day, your marathon training diet and nutrition plan should be pretty honed in!

During high periods of stress — physical and/or emotional — my sensitivity to certain foods gets worse and I have more severe GI issues. When that happens, I have to be very intentional with eating food that isn’t overly processed and sometimes eliminating some gluten-rich foods and dairy. Sometimes even gluten-free but processed foods will upset my stomach, will you’ll see noted below.

For any training run where I have gut issues, I note in my Strava training log what happened and what I’d eaten 1-2 days before that I thought may be triggers. (It can take a couple days for food to work through your system and rear it’s angry head. Other times, it’s an immediate gut upset.) Taking food notes along with the training notes helped me pinpoint that dairy was a major trigger, as well as anything too processed with gluten. I do MUCH better with sprouted bread products than I do white flours or anything super processed.

Okay, onto specifics! Here are two sample days of meals. Remember that the exact portions that you eat will be dependent on your mileage, intensity gender and body size! Don’t follow exactly what I eat since we probably don’t train at the same intensity, run the same distances everyday or weigh the same. Note that I’m not training for a marathon right now, but I am currently running 5-7 miles, 5x a week, so hitting about 25-35 miles a week currently.

What I eat in a day on a 5 mile run day.

• pre-run snack: banana + spoonful of almond butter + energy ball + water + black coffee. I eat this at least 30 minutes before I run so that I have a little time to digest.
• post workout breakfast: water bottle with LMNT while driving home from run + coffee with 2 scoops collagen  + 2 eggs + avocado + tomatoes + two slices of bread
• AM snack: smoothie with protein powder, banana, strawberries, almond milk, spinach and peanut butter
• lunch: salad with arugula, sweet potato, chicken breast, walnuts, apple and dried cherries + homemade tahini dressing + toast with Earth Balance + kombucha
• afternoon snack: apple with peanut butter + a few pieces dark chocolate
• dinner: halibut + fried plantains + rice and a side salad
• post dinner: handful of trail mix + dried apricots

You can see another example of what I eat in a day (on a 7 mile day) here.

What I ate on a 11-mile run day

• pre-run snack: 2 pieces Trader Joe’s gluten-free toast with honey, peanut butter and sliced banana, water with LMNT and black coffee.
• Mid-run: vanilla GU + LMNT
• post run breakfast: Ucan Protein Powder mixed with almond milk (stashed in my car in a shaker bottle) while driving home from run. Once I got home, I had coffee, a bowl of oatmeal (I like the Picky Bar Performance Oatmeal)with a big spoonful of peanut butter mixed it and topped with blueberries.
• Lunch: 2 rolls of sushi + 2 avocado lettuce rolls + kombucha
• afternoon snacks: dark chocolate dipped in almond butter x 3 (ha! I always go back for more!) with decaf coffee. Superhero muffin. Toast with peanut butter. An orange with a handful of mixed nuts. (These were spread out, not eaten all at once!)
• dinner: beef burger with hummus + simple arugula & tomato salad + roasted sweet potato
• 9pm snack:  energy ball + chamomile tea

Tips For Marathon Training Diet

• Keep it simple. We want to make sure our pre marathon nutrition is sustainable!
• Make it fun! Find recipes you’re excited to eat. There’s nothing worse than feeling bored and sick of the foods you’re eating.
• Be patient with yourself. If you notice that you’re starting to feel more sensitive to certain foods, remind yourself that it’s NORMAL when you’re training for something like a marathon! Keep track of what you’re eating so that you can start to pinpoint the issues.
• Order some LMNT and thank me later 😉

Bottom Line

You can’t ignore your diet if you want to see improvements in your running, especially when running a marathon. Educate yourself on the basics of sports nutrition and then start to pay attention to what you eat. And remember, figuring out what foods work well for you may take some trial and error. So practice is as part of your training and not in the final days before your big race!

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