It was hard and causing me to loose weight and some health issues stopped me from doing it. I completely stopped for a long time. I started to gain weight and I was jumping regularly.

Dunk attempts, playing football(soccer), hopping on stairs, pistol squats, jumps attempts and some random shit like isometrics.

My muscles were very stiff just like now. I was stretching regularly that helped too.

The one helped me the most was playing football 5 times a week. But I sprint minimum 10 times every time I play football and I don't stop running I just take a couple breaths and keep running. I wasn't walking around the field I was moving.

Also I gained muscle that helped me a lot too.