Iowa Girl Eats, Peanut Butter Fingers or Fitnessista for some butt-kicking inspiration. I'm telling you, these girls know how to put together a great workout that has you huffing and puffing without taking forever.
After following their routines for quite a while now, I thought it was high time I shared a workout or two of my own. On the days that I don't have to do one of my longer training runs, I like to mix up my cross training days with some speed work to rev up my metabolism and keep things interesting.
Next time you get a little bored, give this workout a try!