How to lose the layer of fat above the muscle (Im 17)

Question
I'm 17, and I have a school swimming race this May/June. I used to have a six pack and toned muscles but after the winter holidays, I seem to have a layer of fat over the muscle which doesn't look as good. So, (to impress all the girls at my school, for I haven't taken part in a swimming race before) I want to build my stamina and lose my fat covering my muscle since winters over and the fat over my muscle is useless. What can I do (such as running)  to gain stamina and make my abs look good?
P.s. I want to do this by running because weightlifting doesn't seem to suit me and I would rather run in the fresh air at my local park which is very hilly and a few acres big.
P.s.s. I am from England if that helps.

Answer
Hi Ryan
With a short period of time to work with i would keep it simple by working your way up so as you can run at a comfortable pace for 45 minutes a day for 7 days a week.You also have to get squeaky clean with real quality balanced meals and i don't have to tell you what is not good for you.If you work real hard at this program you should start seeing results quickly.It is simple but very effective if your committed.There is no magic,just good old fashion hard work.

All the best

John