You should be able to do no more than 10 reps. If you do more then you are not improving your vertical jump very much. Increasing your vertical jump takes a lot of time. You have to have good strength, flexibility, speed, and genetics to have a good vertical leap. You can build strength by doing basic exercises such as squats,lunges,calf raises, or leg extensions (you need a machine to do these) Once you build up your strength, start working on your speed. Do plyometrics to increase your speed. Pylometric exercises help to build explosion in your jump, which gets you higher in the air. Any type of exercise is very demanding on your body, so make sure you don't push yourself too hard, or you will get injured. Take it easy and build yourself up to harder exercises. Make sure you eat plenty of protein and vitamins. Also, you HAVE TO STRETCH before and after you exercise. You are severely damaging your muscles if you don't stretch. Stretching builds elasticity in your muscles, and this helps increase your vertical.
Squats!
Squats are the main excersises that you can do to improve your vertical. They help even more when you add weight.
Exercises like squats, calf raises, lunge and also work on your core like abs.
im tall and im working on jumping higher by doing squats so maybe its just that they either are active or just appear to jump higher
Do a standing hop, step, and jump as many times as you can.
practice jumping, squats, calf raises, step ups, do them consistently and actually work at it. there's no easy shortcut.
trampoline
Various programs out there allows you to improve your jumping. Exercise like calf rises, squats and so on allows are designed to improve your vertical leap.
Pizza
up up
both are good
yes it does