Is 10-12 weeks too little time to marathon if you're a newbie (2nd marathon?) Due to shin splints I can't start my 18 week marathon training plan. I hope to be healed by the 12 week mark, but it might be more like 10 weeks before the marathon. My PT thinks this is plenty of time, but I don't think she realizes how out of shape I am- lol. Once the soreness subsides I plan on doing quite a bit of biking, but I don't have access to a gym to do swimming or anything else. What do you think?