Fuel for Endurance Running

A balanced diet will go far in helping you feel your best, but endurance runners have some special dietary needs to consider. Consuming enough calcium, iron, magnesium, and zinc is essential for maintaining healthy bones, muscles, and immune system. I wrote a guest post on Nutrients for Marathon Training awhile back – check it out for more details!

If you run 3 miles or so a few times a week, you probably don’t need to do anything out of the ordinary. Just make sure you’re eating a balanced breakfast, drinking enough water, and including veggies, whole grains, and lean protein/dairy whenever you can. You certainly don’t need to carbo-load for a 5K 🙂 If, however, you are training for an endurance race such as a triathlon, half-marathon, or marathon you’re going to need to really focus on fueling properly.

How Many Calories Should I Eat?

First things first, everyone’s body is different. What works for me, might not work for you. Eating enough to fuel your running takes a lot of trial and error – I’ve been running for 10 years and I still haven’t figured it all out yet! To get a base line calorie goal, check out the Mayo Clinic’s interactive tool. I don’t count calories everyday, but sometimes on long run days I will estimate to make sure that I’m eating enough to maintain my weight. For me, that could mean close to 3,000 calories. It can be tough to eat that much without feeling overstuffed, so I try to focus on energy-dense, low-volume foods such as: peanut butter, trail mix, homemade granola, olive oil, whole grain, seed bread, avocado, Clif bars, 2% greek yogurt, whole grain banana pancakes, etc. These foods are packed with nutrients AND the calories you need.

Peanut Butter!

If, on the other hand, you are trying to lose weight, you might want to fill up on low-calorie, high volume foods such as melon, berries, apples, raw veggies, salsa, soup, high fiber cereal, fruit & yogurt smoothies, etc.

Raspberries and yogurt

However, I would not recommend trying to lose weight while training for a marathon. It can be done, but the high amounts of mileage you’ll need to complete will require a lot of energy. Doing a long run when you’re hungry and cranky is a recipe for disaster! In fact, many marathoners actually gain a few pounds during their highest mileage weeks – it happened to me! Some researchers theorize that this uptick in body weight comes from the muscles retaining glycogen/extra water while others attribute it to the increase in appetite. In any case, asking your body to run 26.2 miles (or even 13.1!) is intense. Please don’t hesitate to give it what it wants – FUEL.

Fueling Before/After Exercise

Although I still haven’t figured out the perfect formula, I’ve noticed that I feel a lot better when I have a small snack before an early morning run. Ideally, I’d eat a light meal 2-3 hours before running, but on days when I can’t do that I try to eat a 100-150 calorie snack about 20-30 minutes before heading out the door. Food that is low in fiber/fat and high in carbs while minimize tummy troubles. Some of my fav pre-run options:

  • slice of toast with nut butter
  • 1/2 luna or clif bar
  • small bowl of cereal and soymilk
  • handful of raisins
  • banana
  • 1/2 cup plain yogurt with honey


After you finish running, try to drink some water ASAP and have a combo of protein + carbs within an hour (preferably 30 minutes).

Some examples of post-run food:

  • smoothie made with yogurt, frozen fruit, spinach, almond butter, and ice
  • bagel with banana, peanut butter, and honey
  • turkey and hummus sammie on whole wheat
  • veggie soup (perfect for replacing sodium) and whole grain crackers
  • oatmeal with chopped apple and cinnamon
  • hot latte or hot chocolate (it has protein + carbs!) and trail mix
  • homemade pita pizza

Stove top apple oats

Fueling During Long Runs and Races

If you have a big race coming up, you’ll want to try out your breakfast and mid-run snacks in advance. Nothing worse than finding out your scrambled eggs aren’t going to agree with a 10 mile long run. Ugh.

Pre-Race Breakfast

Before both the New York City and Boston marathons, I had basically the same pre-race breakfast: coffee, banana with 2 Tbs peanut butter, cinnamon raisin bagel, and gatorade. I started eating my breakfast about 4 hours before the race start – next time I would add a small snack (1/2 an energy bar) about 30-45 minutes before the gun goes off. If you’re worried about having to use the porta-potties during the race, stop drinking water/gatorade at least an hour before the start. The time buffer will allow your kidneys to empty before you start running. Inside tip: I chew gum while running to keep my mouth from getting too dry.

During the race, a good rule of thumb is to consume 100 calories for every 60 minutes of running. I personally like powergels (chocolate flavor!) and clif shot bloks, but jelly beans, fig newtons, and gummie candy could also work. The key is to get simple sugars into your body ASAP. Most gels are concentrated carbs, so make sure to have a few sips of water or diluted gatorade with your mid-run fuel. As always, practice-practice-practice with this kind of stuff before the big day!  When I was training for Boston, I had no problem digesting gels/shot bloks during slower-paced long runs. However, since my race pace was a minute faster than long run pace, I had a MUCH harder time with fueling during the marathon (think: low blood sugar, nausea, etc). Practice eating gels/drinking gatorade while running your projected race pace – it will prevent any unwanted surprises!

Snickers Marathon Protein Bars & Clif Shot Bloks

Happy Running!

Disclaimer: I’m not a doctor or registered dietitian, just a runner interested in nutrition! The tips provided above are things I’ve learned from personal experiences.

  • Great post! I’ve noticed since I have started running and training for a half I am needing a lot more “fuel”. My consumption of fruit has skyrocketed! I also tend to consumer a lot of Larabars, they are a bit more expensive than Cliff Bars, but most of them are raw and well worth it in my opinion. Plus i Just like the taste better.

  • Lizzy

    This was such a wonderful and helpful post. I’m gearing up for my first half in october, and have been asking anyone and everyone on tips on what works for them! I”ll be for sure referencing this post again and again for my race! 🙂


  • Awesome post Megan! These are all things we should know, but tend to forget haha. Thanks for the great advice!

  • I love your running tips! I feel like your last several posts have got me really over excited – they are very timely for me so thanks!!
    I am still in a conundrum about how to fuel for my 10 miler. Normally for long runs I will have half (or whole) a plain bagel with half a banana smooshed on about an hour to 1.5 hours beforehand. But my race starts at 7am and so I am contemplating not eating anything since I don’t normally eat before my early morning “tempo” runs…but I don’t know if eating nothing is foolish…I am basically going round in circles in my head about what is best! Gah!

    But thank you for awesome advice. You rock!

  • FABULOUS POST – just the good amount of info i needed before the big marathon day (almost two weeks away!). i sometimes run with gum too – keeps my mind busy and my mouth busy!

    i haven’t weighed myself, but my legs definitely feel more muscular, so i wouldn’t be surprised if i have gained a few pounds of muscle.

    thanks for the post lady – have a good friday!

  • Evan Thomas

    Great post! Fueling’s obviously a big thing for me, what with my blog being Food Makes Fun Fuel and all. I tihnk you’re right in that it’s important we all recognize we’re a little different on fueling and no one set plan is best for everyone. I usually eat nothing right before running in the morning, but a ton right before bed, which works for me but definitely not everyone

  • Great suggestions on pre-workout snacks! I usually have a small bowl of cereal. I sometimes see people drinking coffee at the gym before a spinning class or on their way to the gym, and I wonder how they do it. I usually have to go to the bathroom 10 min. after drinking coffee! Ok, TMI, sorry! I guess everyone really is different.


  • Ellen, I hear Yerba Matte is a great energy boost to drink before a run, it’s naturally caffeinated and has less than coffee. It also has other energy boosting properties as well.

  • Ellen – I always leave a 30 minute window between coffee drinking and exercise. A bathroom break before running is very necessary 🙂 Perhaps TMI, but so true…

  • balanceinbites

    This is a really nice write up. I trained for and ran in the new york city marathon a few years ago, and I don’t think I took the good advice you give here. Now, I’m gearing up to start training for another marathon in the spring, and I’ll be checking back on this post as I up my mileage. =)

  • balanceinbites

    Bah, I always forget that these comments don’t link to blogs. My blog is http://www.balanceinbites.com =)

  • Just what I needed to read before Sunday! YAY!

  • Thanks for all of the great insight on what runners should eat. That’s great advice about “testing” out your prerun snacks/meals BEFORE the big day. Otherwise the consequences could be awful!

  • Jennifer

    Just read your comments on Tina’s blog and I’m glad you have to come to LOVE living in NYC! I’m a native and now a DC resident and it just can’t compare!

  • Great post! I’m finding that figuring out what to eat before a run is tough – sometimes I eat too much too close to the run, and it makes for an awful run! But if I don’t eat anything, I feel weak.

    Tricky stuff!

  • caitlin

    wonderful post!

    I was wondering if you could address the “gum” issue a bit more? I also chew gum when I run, and was hoping to hear more about your experience with it.

    I am so used to running with gum, I feel strange and dry-mouthed without it. I usually go through 1 piece ever 20-30 minutes. do you swap for a fresh piece during your runs?

    also, after years of running, I’ve gradually begun to worry about the effects this has on my jaw. Have you noticed any jaw pains?


  • Sheila

    Thank you for this post! This is very helpful and is exactly what I needed! 🙂

    I’m training for my first marathon on Oct. 18. So far I have practiced drinking only drink sports drinks during my LSDs (three Powerades/Gatorades for 3:45 30Ks) and for my recovery drink, a glass of chocolate milk. 🙂

  • Jessica

    Before and after my runs, (when I remember), I drink homemade Chai…. adding extra ginger to help with my digestion. Also eat lots of turkey sandwiches, no mayo, and bananas with peanut butter.