The plank can do it all — besides sculpting arms, the move challenges your balance and engages the core muscles for an extremely effective (and deceptively difficult) gym basic.
- Start facing the floor, resting on your knees.
- Plant your palms on the mat by your head, shoulder-width apart. Your palms should be flat; spread your fingers out wide to help support your weight and take the strain out of your wrists. Step your legs out behind you one at a time, and rest on your toes.
- Contract your abs to prevent your butt from sticking up or sinking. Your spine should be parallel to the floor, with your abs pulling toward the ceiling.
- Hold for 30-60 seconds.