Plank Pikes Place the towels under your toes in a plank position, with your feet slightly apart. Engage your core to lift your hips up and slide your toes toward your shoulders. Slide your feet back to plank position. This completes one rep. Try to do them slowly; Think three to four counts in and three to four counts out. Modification: this can be done on your elbows! Complete 12 to 15 reps.