Scrolling aimlessly through YouTube videos one afternoon in search of some exercise inspiration, I stumbled across ... body warm-up to get my shoulders, arms and chest ready. Are you fed up with ...

benefitting other upper-body exercises like your bench press. I decided to try for 70 reps of weighted push-ups each day for a week, placing a barbell plate across my mid-upper back and repping it ...

How doing 100 push-ups a day for 21 days straight can transform your body and change your mind about this classic bodyweight ...

Think you're strong? These advanced push-up variations will challenge your chest, shoulders, triceps, and core—only the elite can master all six.

Knee push-ups also allow you to get lazy with your lower body positioning. In short, knee pushups ask less of your glutes and core, making them more of an upper-body than a full-body exercise.

There are other ways to make a push-up easier or harder. "When you drop to the knees, you completely eliminate half of your body weight and train improper body mechanics," said Atkins.

The push-up ... Lift knees off the floor, and maintain hand, arm and shoulder alignment. Keep a neutral spine (no sagging hips or head) and create tension and stiffness throughout your body.

"They enable you to get a full body workout with no equipment ... or elevate their midsection too high when performing a knee push up, which puts an awkward amount of weight on your knees ...