Start on all fours with your knees below your hips and your hands below your shoulders. Set your spine in a neutral position, and draw your shoulder blades down and back. Tuck your toes, then lift your knees off the mat, resting on the balls of your feet.
Take a small step forward with your left foot and your right hand at the same time, ensuring that you keep your abs engaged so your torso remains parallel to the ground.
Take a small step forward with your right foot and your left hand at the same time, once again ensuring that you keep your abs engaged.
Continue alternating until you've reached the end of your mat or have taken 10 steps (if you don't have a yoga mat), then repeat this motion backward.