Equipment: 

Bodyweight

Why this variation?

This is an advanced functional variation of the squat, adding a challenge to balance and stability. As soon as you change to a single leg movement, you add twice as much weight on every muscle and joint. Also, since you're on one leg, the ankle, knee and hip on that side have to work to stabilize everything. So, the amount of stabilization and balance needed as well as the extra load makes the movement very difficult. This advanced move is for experienced individuals looking for a much harder challenge for a squat that is still bodyweight.

You can also try this in an assisted way and build up strength using a band, TRX or suspension straps. This is really good to help knee stability, hip stability, ankle stability and your balance in general. You're able to help yourself enough so you're not adding too much weight for a single leg if you're are still working on your strength and balance.