Plank tap ||| h3
You can do this one just about anywhere—all you need is a sturdy support, such as a chair or park bench.
HOW TO DO IT
Get into an incline push-up position with your hands shoulder-width apart on the seat of a sturdy chair or the edge of a counter. Extend your legs behind you, feet hip-width apart. Touch your left shoulder with your right hand, then return your hand to the starting position and repeat on the opposite side. Continue, alternating sides.