Stand tall. Looking straight ahead with chest up, shoulders back and down abs braced.
Lunge forward, bending the knee, making sure the knee doesn’t go over the toes. Keeping the opposite knee off the ground. Push up through the heel of the leading leg to raise yourself upright.
Without pausing in the centre reverse the motion and step back with the same leg. Bend the leg and lower the knee toward the floor, but not touching it to the floor. Push through the forward heel to raise yourself upright. That is one rep.