Search:

And yet when Lance ran the NYC Marathon, he said it was brutal (because of the leg pounding).

This thread delivers

30 degrees outward

Heart rate monitors are for the most part accurate, but there will be times my hr monitor has jumped to 220+, from seeing how you walked and it was 157 take it as a glitch in the matrix.

Tabata's:
20 seconds of all out running:10 seconds resting (walking or resting)
--
Springting up a hill than fast walking down
--
Run 1min on, 1 min off, 1 min on, 50 sec off, 1 min on, 40 sec...

If you can deal with the intensity:

www.crossfitendurance.com