Re: Has anyone drastically improved their vert in their 20s?
it is definitely possible. I know a lot of guys who couldn't dunk in HS but can dunk easily now. They're not doing windmills or anything but they had realistic goals in mind when they set out to improve.
if you increase 3 inches a year, that's 9 inches in 3 years. That is amazing growth from realistic short term goals. Aim for the short term goals and try to build on them every year.
DO NOT make the mistakes others make. There is only a certain amount of training your body/central nervous system can take. For someone with your physique it will take a lot of patience and time to achieve the requisite athletic ability in order to dunk. But it is definitely possible.
It won't happen over night. I know it sounds cliché but it's something you need to internalize and really take to heart. You will do more harm than good if you really try to rush this process. My friends trained for around 5 to 6 years to go from barely touching rim to dunking easily with two hands. Train hard when you can, and if you can't, rest. The stronger you get, the more frequent you can go hard so don't go nuts right away.