Some good articles on WFN for this topic:
http://worldfitnessnetwork.com…..r-85-tips/
http://worldfitnessnetwork.com…..ogression/
There are more but these are the most applicable.
RunnersWorld.com is also a great site, though be careful – most people there are running snobs and frown on lifting weights. But the running advice is pretty good.
But depending on your size, you need to be careful. Running is a really rough sport for bigger guys. I've read reports that the pounding force is some huge multiple of your weight (10x? 20x? nto sure). So that means a 200 pound guy's knees take a lot more pounding than a 160 pound guy's knees. Age plays a slight role because joints become less pliable as we age and recovery takes longer. But at 31 your should have no trouble with that.
Back when I was bridging that gap from doing "2 mile runs" to doing "5 mile runs" my problem was not cardio/breathing – it was in my legs and joints. So what I did was
- slowly increasing, like 0.25 miles a week per run
- no more than 3 runs a week
- carefully scheduling leg days around running days
- keep moving; if I was supposed to do 3.5 miles and I was getting leg cramps at 2.5 miles I would try slowing my pace so that it didn't hurt; if that didn't work, I'd walk for a while; then I'd pick back up and run as soon as I could
- lots of sleep
When I increased from 5 miles, 3x a week to 30 miles a week total, some keys were
- reduced lifting (there's almost no way to run 30 + miles a week and also do legs more than once a week, so I went to a 3 lifts per week routine: legs one day, pulling one day, and pushing one day
- staggered distances (some days doing faster but shorter runs, other days doing longer but slower runs)
- throwing in a day of intervals over a long distance (so, say, an 8 mile run/walk/sprint)
- bringing gels with me to fuel up after about 5 miles or so
- losing some weight; I dropped about 15 pounds before I did the Oklahoma City marathon; too much of a loss for me which is part of why I only run about 15 miles a week now