After the nutrition fail I experienced during my 17 mile run last weekend, I decided I needed to research proper fueling and come up with a plan. I still have time to work this out before the marathon.
On Active.com I found an article called "4 Steps to Perfect Marathon Fueling". It gives a series of formulas to determine how many calories you should consume during the marathon.
1- Determine running calorie expenditure per mile
0.63 x body weight in pounds (for me 0.63 x 130 = 81.9)
2- Determine goal race pace, or how many miles per hour you'll cover
My marathon has a 6 hour cutoff. Based on the comfort level of my 17 mile run, I think I may be able to run faster, but that's not my goal and I'm not pressuring myself to do so. So, I'll just take the cutoff numbers of 13:44 pace/mile, which is 4.37 miles per hour.
3- Calculate hourly expenditure based on goal race pace
goal race pace in mph x the figure from step 1 (for me 4.37mph x 81.9 = 357.903)
4- Determine hourly calorie replacement
Research shows runners can physically absorb 30% of what they expend, so 0.3 x figure from step 3
(for me 0.3 x 357.903 = 107.3709)
The article recommends starting calorie replacement after the initial 60-90 minutes. This would be a little over 3 Honey Stinger waffles if I stick with that fuel. I could also do 3 waffles plus some Honey Stinger chews.
This is something for me to practice on my 20 miler next weekend.
Do you have trouble fueling on long runs? What kind of fuel do you like? How much and how frequently?