If you want to seriously improve your upper-body strength, sculpt your shoulders, and chisel your core with just one single move, it’s time you start doing the pushup. I don’t just say this because I’m a fitness editor and by default a true believer in functional, fundamental exercises, particularly the hard ones that most of us put off. Credit: http://www.womenshealthmag.com/fitness/how-to-do-a-pushup-challenge/