Check out Mark Sisson's site marksdailyapple.com.

He's a primal eating/exercising guru who used to be an endurance athlete (marathons). He's got a lot of info on his site, do a few searches. One thing you'll definitely find on there is the advice to not think you can both get freakishly strong AND train for a marathon/triahtlon at the same time. You may need to choose. And yes, you're probably going to need somewhat more carbs for endurance training, so search for that too.