These kids got these leaps after 6 weeks of training apparently. They mention a couple of guides and also Springbak Springsoles. You can check those out here - http://springsoles.co.uk

In this article I am going to cover exercises to increase your vertical jump and slam dunk. There are two main categories of training that you should incorporate into your routine. The first is plyometric exercises, which train your body to increase its muscular power. Muscular power is what drives your body when it explodes [...]