How much should I run?

I've been working on my speed for quite a while, now. However, I've only ever ran in quick bursts. No further than 100 meters. However, now I'm trying to run further. I've began running slower for longer periods of time in an attempt to increase my stamina. After running 5 miles (and feeling like I'm gonna die), I thought about the next time I'd be running. I didn't want to do it the very next day, as I've heard that's bad for your knees. (I don't have too much to worry about, being 17 and all, but I don't want that to come back and haunt me in later years). So if I'm running 5 miles a day, at a slower pace of 12 miles per hour, how many days a week should I do this?


Why not run every other day, and cross train on the opposing days, leaving at least 1 day for rest (no structured exercise)? Cross training will give your body a break from running (many running injuries are due to repetitive motion because the runner does no other activity). Increase your distance gradually (rule of thumb used to be no more than 10% per week), and run slower as you're going farther. You might also consider doing run/walk intervals as you increase your distance. Take care of your body. Some people can run daily and are fine (until they aren't). But to be a better runner in general, workout with weights or do some cross training that isn't running. Make your body stronger, so it can carry you on your runs farther and faster.