Stand with your feet shoulder-width apart
Push your weight back into your heels – you should be able to lift up your toes
Slightly bend your knees and put your arms out straight in front of you for balance
Sit back as if going to sit in an invisible chair – keep your back straight and legs at a 90º angle (if you can – if not, try to go as low as you can without your knees turning outwards)
Keep your knees behind your toes and push back up to stand
Now pulse, coming up a centimeter and down twice.
Now come back up to standing and go through the whole thing again.

Dumbbell no. 65: Build rock-solid quads with jumps, squats and scissors