Marathon Nutrition with Mark Kennedy, creator of “Fuel My Run”

Before my first attempt at the marathon I bragged to my friends and former coach about how I’d negative split the final miles in Central Park.

After the race, I got the biggest “I told ya so!” of my life from runners who knew better.Marathon Nutrition

See, I hit the wall – hard. My pace through 20 miles was 6:06 but soon I was painfully shuffling along, even considering a stop around mile 23 when each step felt like a hammer crushing my quadriceps.

Soon I clipped off a 6:34 mile. Then a 6:44. My slowest was 7:09. Ouch.

Hindsight is 20/20 and looking back, I missed a crucial piece of the puzzle: I didn’t take marathon nutrition seriously.

Before racing 26.2 miles it was never a priority to worry about calories or carbohydrates. A normal breakfast of toast and a banana was all I needed.

And I paid the price with a dramatic bonk that left me nearly crippled with IT band syndrome and a bruised ego. I doubted I’d race another marathon ever again (and considered retiring from competitive running altogether).

But after I finally got healthy and built up the courage to tackle my second marathon, I knew I needed to take nutrition and carbohydrate loading more seriously.

I made significant changes to how I prepared, particularly nutrition, and ran the 2011 Philadelphia Marathon in 2:39:32 – a personal best by over five minutes.

What’s fascinating is that my 20-mile split at NYC (2:01:58) and Philly (2:01:16) were almost the same. The real improvement came during the last 6.2 miles when I was able to continue running strong. It’s never easy, but a sound fueling strategy can make those last miles much more bearable.

How to Plan Marathon Nutrition Like a Pro

To learn more about how to plan your race day fueling, I got on the phone with Mark Kennedy, a former kinesiologist who recently created the Fuel My Run app.

The app helps you make a nutrition plan for your marathon or half marathon using current products and the latest science on optimal fueling.

In this 35+ minute interview, we discuss:

  • Our eerily similar debut marathons – and personal details about how we suffered from hitting the wall
  • The other reason why Mark ran a marathon in Dublin, Ireland…
  • The steps we took to refine our marathon nutrition approach (and how it resulted in big PR’s for both of us)
  • How many carbs you need for a “meaningful performance” every hour for a marathon or half marathon
  • The top resources for marathon fueling that Mark recommends
  • Healthy eating vs. performance fueling
  • How runners who have bonked can use this new app to avoid the wall and finish strong

This is a more personal interview – in fact, it’s more like a conversation about how two runners failed, learned from their mistakes, and came back stronger than ever.

Click the grey player below to listen now. Or you can click here to open the interview in a new tab (right click to save).


I hope you enjoy our chat and find it helpful as you plan your marathon nutrition for your next race. Good luck!

To learn more about the Fuel My Run app, you can check it out on iTunes here.

Here’s my favorite quote from the interview (yes, I realize I’m quoting myself, but I’m ok with that):

You can’t take advantage of good training during the last 10k of a marathon if you don’t have enough fuel to do so.

Before we finish, let’s hear about your marathon fueling story in the comments below. What was your big failure? Were you able to turn it around and succeed the next time?

What questions about marathon nutrition do you have that we didn’t cover in the interview?

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  1. So – to get the minimum of 60 grams of carbs per hour, a runner should take in a gel every half hour with drinks of Gatorade in between to get closer to the 60 grams? I took in gels every half hour of my lady marathon – without the sports drinks and felt I could have used a little more. This time around all my gels (Gu’s, specifically the Chocolate Outburst flavor) have caffeine. This definitely helps. My 2nd marathon is in just 3 days : )

  2. Darn auto correct – *last marathon, not lady marathon. Sorry!

  3. Hi Laura,

    Yes, taking in gels and a sport drink will make it much easier to get to 60 grams CHO per hour.

    I am sure you know this, but important to take your gels with a couple of sips of water.

    Best of luck in your 2nd marathon. Let me know how you get on!


    • Hi Mark,

      I should be standing in my coral getting ready to run my marathon, but unfortunately the race has been cancelled : (

      I will remember for my next one about the 60 CHO per hour. Thanks Jason and Mark for this great podcast.

  4. I just did my second marathon three weeks ago. I pr’d at 3:35 from 3:43 which I’m very well pleased. However, my pace went from a strong 8:00 min/mile at 20 miles in to hitting up to a 9:00 min/mile during the last 10k. The last 10k was incredibly tough. Once I finished I experienced calf cramps, dehydration, a blood sugar drop (I’m diabetic) and spent a half hour in the medical aid tent to get my levels right. I drank at every water station (every 2 miles) and used several gu packs and cliff shot blocks. It wasn’t enough and it cost me probably 5:00 on my time. This audio link was great timing! I’m running my third marathon in february and I’m going to take the advice learned here today to help prep. Thanks Jason…good stuff!

  5. Congrats David!

    I have actually received emails from two diabetic runners since releasing my app. It sounds like it could come in handy to help manage carb intake to avoid low blood sugar.

    Best of luck in your next race.