Press your hands into the floor to lift your torso ... you gain — but be sure to still safely maintain proper form. Plank jacks get your heart pumping during your strength routine.

Put your hands on the floor below your shoulders ... Repeat 10 times per knee. The plank jack falls in between plank and mountain climbers in terms of intensity, making for a perfect stepping ...

Plank jacks combine core engagement with cardio ... Lift your legs and upper body, reaching your hands toward your toes.