Fueling for your Fall Marathon (or Half!) Part 1 of 3

It seems like every year more and more folks sign up for fall half-marathons and marathons. For the uninitiated, a marathon is a full 26.2 miles (that’s 42.2 kilometers for my metric friends), which means that the brave souls undertaking a full or half-marathon have many, many weeks—months, even—of training.

I’m tackling my seventh marathon this fall, but they truly don’t get easier!

Really effective training for an endurance event (and believe me, a marathon is quite a thing to endure!) requires runners to complete different types of runs most days of the week for 16-20 weeks: A long slow run one day a week followed by a slow recovery run the next; hill workouts (my mortal nemesis the hill and I spend a lot of time together in the summer); runs with intervals of speed and recovery…you get the idea.

The Baltimore Running Festival is coming up in October, and I gave a talk to a fantastic group of runners at Charm City Run this past week. We covered a lot of ground, including some great questions…

Q: What is the goal of all this flippin’ training and careful eating? Why can’t we just do some runs here and there, eat whatever, and show up in a cute outfit at the start line?

A: You’re working to condition your muscles to work at an intense and long effort, and conditioning your body to burn fat at a high rate during running.

Follow up Q: Why is it important to burn fat when I’m running?

Follow up A: Slightly more complicated answer. Let’s dig in to how our body provides energy for running…

We draw on two sources of stored fuel in our bodies for energy:

1. Stored Carbohydrates (aka glycogen)
I like to imagine my stored carbohydrates as a tiny vial of rocket fuel that powers hard effort, like sprinting away from a bear or dropping and doing 20 push-ups. You store enough carbs to fuel about 1-2 hours of exercise at a hard effort. When you run out of carbs for fuel, your body shuts down and you hit “The Wall:” Extraordinary pain, confusion, general freaked-outed-ness, and the potential for serious problems, like conking out right on the course.

2. Stored Fat 
I like to imagine stored fats in my body as a ginormous jug of fuel with a lid. Fat is great fuel for exercise at a less intense effort where you can breathe easily, like an easy bike ride or a slow run. We have hours and hours of fat fuel to burn (even the slimmest of you!). The only catch is that turning fat into energy takes a lot of oxygen aka breathing (here's where I imagine popping off the lid of the jug to get oxygen to that fantastic fat fuel).

Because you have so much more fat available for fuel than carbs, it’s ideal to use as much fat as possible and to conserve and replenish your carb stores. You'll desperately need those carbs at, say, mile 18 or 20 (or 21 or 22 or 23 or 24...you follow me).

That means that you have to carefully pace yourself in your race, making sure that you don't go out to fast and burn up all of your carbs. The less effort it takes to run, the easier it is to breathe, the more oxygen is getting to your cells, the more fat can be converted to energy and the more stored carbohydrate (aka rocket fuel) you can conserve.

So now the big question: What is the best way to eat so I have a full store of carbs and I'm not setting myself up to go crashing head first into The Wall?

Great question! Check back for answers in Part 2 coming later in the week, or get in touch with me at lauren@live-full.com to schedule a one-on-one conversation.