Question

Having read lots about it in the paper recently - should I come to the conclusion that there's nothing to be gained by doing exercise?
Apparantly it does nothing for you if you want to lose weight, which, frankly, is why most people take up running in the first place.
I have evidence, if not proof, that this is right: a friend trained for and completed the London marathon and compained that she didn't become the sleek gazelle-like athlete she'd imagined was her due after all that effort. She certainly isn't - and wasn't - overweight but there was no danger of stick-insectyness either.
So, am I right to settle back safe in the knowledge that I haven't wasted a moment of my life by doing just 30 mins of running in the past 3 weeks - or should I seek out inspirational stories to get me back pounding the streets again?
WHY DOES ANYONE RUN?? PLEASE TELL ME.