How to develop a six pack when im young and basically fit already?

May depend on a vari: This may be due to a variety of reasons including: your general health, your underlying general health, Genetics, diet, what is and what is not your fitness. You can discuss this with your physician.

6 pack?: In order to have a "6 pack" you need to be fit but also have a low percentage of body fat. This is an exercise and diet issue. There are many different specific work out routines to explore.

Abs and cardio.: You need to strengthen the abdominal muscles with crunches and knee lifts, for example, but you also need to shed the fat so the muscles will show - cardiovascular exercise is necessary in this regard.