There are several factors which are very important in achieving a higher jump and dunking a basketball. I’ve made a list of basic elements you should keep in mind when you start training. Some are more important than others, but it’s good to have an idea about all of them. An example of a great thing to always remember: Increasing your leg power is no good if you are damaging your knees.
The first element is grip, you should start to practice handling the ball every chance you get. With good grip it is so much easier to dunk a basketball. Don’t worry if you are lacking in this department. Improvement is possible and the higher your vertical leap gets, you’ll need less grip strength although it still obviously would help a lot! Invest in a good pair of shoes. Most players find that high-quality shoes improve their ability to dunk a basketball, and more importantly, good shoes prevent you from getting hurt when you try to dunk.
Start with an adjustable height rim, if you have one. Lower it so you can get a feel for dunking, then raise it gradually to the normal height as your jumping height improves. If you have grip problems or still can’t dunk a normal-sized ball, it’s a good idea to practice with smaller balls. You can even use a tennis bal to begin with. This is a bit easier, but if you succeed in dunking with smaller balls it’s a sign that you are making progress.
It can be very motivating to dunk, and you’ll want to train even harder and achieve an even higher jump. Most people jump off of one foot, but some people find that they jump higher off of two. Find what works for you. Once you have a 40+ inch leap you’ll probably be able to dunk in whatever way you want. Build your core strength. I recommend doing squats, lunges and calf raises. These will improve your strength and power. Endurance should not be neglected either. Plyometrics and rope-skipping are tried and tested methods. They will improve your quickness and speed. Stay flexible: stretching will benefit you greatly. Especially your hamstrings. If your muscles are rigid they will hamper your natural jumping motion and cause you to lose power. Stretching is also an important aspect of injury-prevention Land on the ball of your feet, and bend your knees upon impact. This will absorb the forces and at the same time you are ready for your next movement.
With all the above hints, as you can imagine, the most important factor to dunking a basketball is increasing your vertical leap, and you can do this the fastest way possible. Luckily, there is a manual for you written by a professional coach (who has even helped NBA athletes) that shows you the most effective methods. It tells you what specific exercise to do and when. What to do for faster recovery, how much time you should train and recover, what food choices will help you perform better. And much, much more. I have written an extensive review about Vert Shock here. This program has helped me a lot and it might be beneficial to you too!