Enter any gym, and you’ll see the same core workout: crunches, situps, ab machines, and endless twisting exercises. The logic ...

According to experts, it takes just four core workouts to absolutely rip your top half to shreds, so you can get stronger.

Core training has always been part of military PT and fitness testing. From crunches to sit-ups, flutter kicks, leg tucks and plank poses, the U.S. military uses many exercises to test core strength.

These are the moves that will build the upper body strength and size you want.

It’s only six moves and you do each one lying on your back ...