It depends on how much running experience you have already and how much time you have to train.
Well if it were me I would train my legs as much as I can in fact I would train the day I heard about the marathon.
too much
to find out how much a train weighs
I am 6'1" and weigh 170 with a BMI of 22
because they train harder than sprinters. try to run a marathon then you'll understand why they deserve more money than sprinters.
This is a good website to start with: http://www.guardian.co.uk/lifeandstyle/2012/apr/18/how-much-water-drink-marathon The typical answer seems to be about 1.2 litres/hr
By drinking alot of water. but not so much you'll drown yourself. you should be drinking half your body weight in water (oz). Eat healthy. Proteins, carbs, vitamins. Wear your sweats when you run to warm up. Stretch alot. Run 30-1 hour minutes at least 5 times a weak. But once you're start getting into shape run longer distances. ICE ICE ICE your injuries and make sure your shoes have full support.
24.7
One mile increase per week, so 26 weeks if you haven't run much before
8ounces
Half
42