A two-legged squat where you rise onto the balls of your feet and lean your whole body backwards as you lower down. The knees travel far past the toes, so the quads carry everything. It's as much a balance test as a strength one, and the backward lean feels alarming the first few times.
Own the full squat first. Your knees need some conditioning before going this deep over the toes.
How to do it
Stand up straight, feet shoulder-width apart. Bend at the knees and lean back as you descend, rolling onto the balls of your feet. Keep the body in one straight line from knees to shoulders the whole way down. At the bottom, push through the quads to stand back up, keeping the lean until you're upright.
Learn more here:
Source: Ashton Fitness · The Forbidden Calisthenics Leg Exercise (Here's How to Do It) | HOW TO SISSY SQUAT
Key tips
- Keep leaning back on the way up too. Bending at the waist takes the tension off the quads
- If the full lean is too hard, allow a slight hip hinge at first and iron it out over time
- Knees over toes is fine once conditioned. Start with the supported version and build up
- Skater squats, pistol squats and freestanding calf raises all carry over to the balance and quad strength