I've been running off and on for the last few years. I'll average around 15-30 miles a week for a couple months and then I'll have several months where I don't run more than 10 miles a week. I'm currently weigh about 170 pounds and plan to add a few more. Over the last 4 months I've decided to improve on my physic and have focused primarily on weight training on both legs and upperbody. My weekly running miles have been around 4. Right now my racing times are as follow: 5k, between 19:45 and 20:40 depending on the terrain, and my half marathons are at 1:37:00 on somewhat hilly terrain with having done no speed work,intervals, etc and averageing only 3-4 miles a week. I have not done any interval training in over 3 months and it's been almost 7 months since I've done any kind of speed work or intervals. I want to know if it's feasable for anyone who weighs more than 165lbs like myself to break 18 minutes for a 5k. For instance if I stuck with a training program for over 2-3 years instead of 2-3 months. Also is it possible for someone at this type of weight to run cross country for a college? And what kind of 5k and 8k times do most colleges require?
Any input would be most helpfull.
Thanks