Maintaining Mileage with some Thermodynamics

Since my 22nd birthday, I've run just over 1200 miles with my first marathon last November included in that somewhere. I've noticed that various treadmills and my GPS watch tell me that I use about 110 Calories per mile. That means I've used around 100,000 dietary calories which roughly translates into 500 megajoules of energy over those 1200 miles. That (according to Wolfram Alpha) is over 10 times the amount of food energy Michael Phelps consumed per day while training for the Olympics.

It's also 42 times the kinetic energy of a 40 ton semi-trailer truck moving at 60mph. My favorite comparison I found while doing this is that for an instant, that 40 ton truck has the same amount of energy as my iPhone will use in one year.

 I promise I have a life and didn't spend more than 30 minutes doing this...

I wonder how much of the energy I used actually went into moving my arms and legs and how much went into heat. As I wonder that, I'll be slowly increasing my weekly mileage in preparation for another marathon sometime this fall.

:^)