When "X marks the spot" you know you're going to have to do a lot cardio and the X Marks the Spot workout doesn't disappoint. This is one for those who hate running but like cardio, or who know they need cardio but don't want to hit the road or simply have a little time on their hands the need to push their aerobic performance levels up a notch. Take it in any combination you want, you know what it works: your legs, your arms, your lungs, your heart.
Extra Credit: 30 seconds rest between sets.
