You may think doing a pushup is all about arm strength, but doing one correctly depends a lot on your core strength.

You can change the focus of the exercise by adjusting the angle of your upper arms, or by moving your hands. In a traditional ...

For example, try lowering into a push-up for a slow count of three to five seconds, then press up quickly on a one-second count. Pro tip: If you want to make a bodyweight arm workout even harder ...