Training: What Really Works
Looking back I must say that it’s really about the right exercises, the intensity and the number of repetitions (that’s why jumping as much as you can will give you only minimal results).
2) It’s obvious that you won’t be able to dunk if you are overweight. And if you’re not, you can build up some muscles and almost always reduce your body fat percentage (unless it’s below 6 %).
Also, losing fat is how you get (to see) a six-pack, not doing 10 crunches every other day. You need to get your body fat percentage under 11% (<18 % for women) to really see the abdominal muscles.
The abs aren’t that important in the jumping process, but it isn’t only about the calves either. Core strength is crucial to transfer the energy from your upper body (shoulders, arms) to the legs.