The one-leg inchworm is an advanced variation of the traditional inchworm exercise that adds a balance and stability challenge. Begin in a standing position with your feet hip-width apart and lift one leg off the ground. Hinge at the hips and walk your hands out in front of you until you reach a plank position, then walk your hands back towards your feet and return to standing, engaging your core and balancing on one leg throughout the movement for a comprehensive lower body and core workout.