Staying injury free is easy as 1-2-3. Just remember these three easy rules for maintaining healthy running:
1) Don't Run With Pain
This sounds pretty obvious, but many of us violate this rule big time. Here's the problem: If you are running with pain, you are compromising your form in some way, guaranteed. Limping along will cause trouble in your back, your knees, achilles...you get the idea. Know the pain scale. If you are experiencing minor pain (a "3" on the pain scale), keep on going. If pain rises above a 3, STOP and treat the injury.
2) Increase your Mileage No More Than 10% Weekly
If you're training for a race, plan, plan, plan. Do not increase your total weekly mileage by more than 10% weekly. Doing so simply invites injury and down-time. Example: if you've been running 30 miles a week, week two increases to 33 miles.
3) Your Longest Weekly Run, Should Not be More Than Half Your Weekly Mileage
The key to the long run is learning the ability to maintain form through the miles. Again, disintegration of form is the recipe for disaster. If you run 30 miles a week, your long run should be no longer than 15 miles.