Run a Faster Marathon
Credit: Joe Drivas / Getty Images

Now that you're a marathoner, with endorphins firing and your body itching for weekend runs, it’s time to learn when to push yourself and when to relax. “Running can become a borderline obsession,” says Metzler. “Even though you’re physically able to do it, you don’t realize you’re not letting your body recover. If you’re running hard every day you’re going to burn yourself out. You’ll be fatigued and never really recover.” Over training will lead to you feeling flat and sluggish on race day because your body isn’t able to process the oxygen very well. The key to rest is taking your days off easy enough that you can push yourself on those days you’ve set aside for hard workouts.

And get some sleep. “Your capillary beds are increasing and your muscle fibers are growing. There’s a lot of maintenance repair your body is doing while you’re sleeping.”

Key Workout: Focus on tough 14-mile runs will help you build up the strength and endurance in your legs while allowing you to fully recover for the race, rather than the longer 22-mile runs that can burn you out before the big day. You can also increase your training program from 16 to 24 weeks, giving you more time to build an aerobic base.