Side Plank (Vasisthasana)
From Plank Pose, shift your weight to your left side, rolling onto the outside edge of your left foot and stacking the right foot on top. Reach your right arm straight up in the air as the left arm stays anchored into the mat, slightly in front of the shoulder, supporting your upper body. Keep your head in a neutral position, or turn it to gaze up at your right fingers. For an additional challenge, lift your right leg so that is perpendicular with the floor. Repeat on the other side.