I can't believe some of the responses on this thread.
Some of you are really gifted runners based on some of the times that have posted. I will never be able to touch those times and it pisses me off! My advice to you is to continue to run, even if it is 20 miles per week. What's that lame line? "Don't sacrifice the gift"? Whatever it is, seriously DON'T.
Running changed my life and I didn't really start "training" until I was 31. I was never fat, or really out of shape, but I never believed I'd be in the shape that I'm in right now five years ago. Seriously, a 4:54 mile at age 33? If someone were to tell me that back then I would have laughed at them.
Unspectacular times aside, I have a perfect bill of health and a very youthful appearance due to keeping in shape. The training you do leads to other healthy habits, especially eating right. You eat the right foods full well knowing that you have a hard workout ahead that needs the proper fueling. I have more energy than I ever did it's translated into my working profession.
I have friends who are in their thirties who look like absolute shit. I'm talking skinny-ass dudes in HS who are far over 200lbs now. (This could be some of you in the next ten years!) Years of drinking and eating like they did when they were 13 have destroyed their appearance. I get the sense they are pretty unhappy. Girls I once found stunning in college are now whales. It's not a pretty site.
Do yourselves a favor and keep at it to maintain your health. You can still run 40 mpw and have a great social life. So what if you are dropping 18:XX 5K's on the weekend, at least you're out there...