Ive just started a healty lifestyle kick. I haven't done any phisical training for about 8 years but recently joined a gym and started running on a thredmill. I can do a 2 mile run in 20 min which seems to be getting easier to do as I normally work out 4-5 days a week. I've looked at a 21 week marathon training programme and it starts with a 6 mile run on day 1 and works up gradually from there. How long should I leave it before I start pushing extra distance on my running. I can't do the basic six miles at the moment. I'm 31, 5' 9" and plan on running a marathon in june '09. Am I crazy?

Oh ya almost forgot and I weigh about 11.5 stone (approx 170 lbs I think)

It's certainly possible. Typical rule is not to increase weekly mileage by more than about 10%. If you're having trouble going for longer distances, it means you have to slow down. You might want to follow a schedule provided at http://www.halhigdon.com

Thanks for the advice flier. I had a look at that website and it had some good advice and a more realistic training regime. Thanks again.