Source: http://www.bornfitness.com/the-david-beckham-cardio-workout-that-will-make-you-drop/
For more than 10 years, my job has been observing, following, and sharing the stories of some of the fittest people in the world. The one problem: most of their workouts have been edited by magazines to make them more “doable” for the average person.
It makes sense, but also can be a little deceiving. Year after year people ask me, “What are the hardest workouts you’ve seen?”
If you’re looking for an abs workout, sprints are the secret weapon of all…