Stand facing away from the stairs with your feet just past hip-width apart. Place your hands behind your ears so your elbows point out and pull your core in toward your spine.
Looking straight ahead, bend at both the hips and knees, ensuring that your knees remain in line with your toes. Continue bending your knees until your thighs are parallel with the floor and your butt taps the second stair behind you. Ensure that your back remains between a 45- to 90-degree angle to your hips. You won't fully sit on the stair, but hover just above it or lightly tap it.
As soon as you touch the stair, drive through your heels and straighten your legs to return to standing. This counts as one rep.
Complete for two sets of 12 to 16 reps, resting for 45 seconds between sets.