Sunday, August 12, 2012

Fueling Plan

If any of you follow me on Daily Mile, you'd know that my Saturday long runs on July 28th and August 4th did not go very well for me. Those runs were 13 and 14 miles, respectively, and in addition to the oppressive humidity on both days, I also "hit the wall" around mile 10 in both runs. After examining all of my data from those runs, I came to the conclusion that my fueling plan for my long runs was woefully inadequate.

Since I'm part of the Runner's World Challenge for the Marine Corps Marathon, I decided to ask the question on the discussion board about fueling and hydration. The response I got back from the RW nutritionist, Pamela Nisevich, instantly set off the light bulb above my head. The carbo loading can begin the day before my long run at lunch, which would be Friday. High carbs, low fat, low fiber, but not so much food that you're weighed down. Dinner that night would be the same, but the lunch carb load was in case I didn't get the chance to do a nice carb intake at dinner. Lunch on Friday was a baked potato (plain), with some pasta & sauce, some fruits & veggies, and some Chobani. Dinner was pancakes. Lots of pancakes.

On my long run day (Saturday), Pam's advice was to take your weight, and at breakfast:
multiply this number by the hours you have until your run begins.
For example, say you weigh 190 lbs and you roll out of bed an hour before the run (or race) is to begin.  
190lb/2 = 95
95 x 1hr = 95
This means that you need 95 grams of carbs for breakfast.

I'm 207 lbs. right now, and I eat an hour or so before my run, so I need about 103 grams of carbs. OK, that seems like a lot of food, but this is how I divided it out: 1 serving of Trader Joe's steel-cut oats (25 grams), one sesame bagel (46 grams), one banana (20 grams), a glass of orange juice (22 grams), and one cup of black coffee. That's 113 grams of carbs, and I didn't feel weighed down.

Pam also suggested that since I take GU during my runs, to make sure that I took 2 GU's per hour, washed down with water. I was taking only one per hour previously. Pam said that I needed to aim for about 45 grams of carbs per hour.

So, all carbed up, with my Nathan hydration vest filled with lemon-lime Gatorade (the on-course beverage of choice for the Marine Corps Marathon) and 4 GU packets, I set out for my 15 mile run. Luckily, the weather was not as heinous as it had been the previous 2 weeks. I started out more conservatively than I had before, running the first 4 miles in exactly 40 minutes. I try to run by effort, using my Garmin to track my heart rate; this week's run was a combination goal of a heart rate below 75% and a 10-minute/mile pace.

The results were astonishing. I didn't bonk at mile 10, like before. In fact, I actually had enough energy stored to where I ran my fastest mile of the day in mile 14 (9:41 pace). My final totals were 15 miles in 2:29:43 (9:58 pace) and an average heart rate of 143 (73%), both figures right on target.

It's exactly what I was looking for: smart advice about how to properly carb load for a long run to prevent the dreaded "bonk". Combined with a conservative running strategy, it made for a very successful run. I plan to use this going forward through October 28th, in hopes of a very successful first marathon experience.


  1. Dave,

    Thanks so much for the information and formula. I have been wondering how to figure this into my nutrition plan and you just provided the solution.

    Best wishes my friend,


  2. I like Pam's equation. I'm going to have to try that for my next long run. I also just discovered this fueling calculator. Very interesting!

  3. Dave an interesting post I have also been giving the whole fuel thing some thought for my forthcoming half and full marathon as I felt that on reflection my fuelling prep has not been as it should have been.