You're an intermediate marathon runner if you've run a marathon before and you have a specific goal in mind for your next one.

iStockphoto/Thinkstock

Intermediate marathon training is about taking your body to the next level of running. But how do you know if you're an intermediate runner?

Specifically, an intermediate runner is someone who, for the past year or so, has run four to five times a week, 45 to 90 minutes each session, for a total of 20 to 40 miles (32.19 to 64.38 kilometers) a week, including a weekly long haul of 10 miles (16.09 kilometers). You've probably also completed -- or even raced -- a 5K (3.1 miles), 10K (6.2 miles) or half-marathon. You're truly ready for intermediate marathon training if you've run a marathon before but would like to finish it this time with a specific time goal in mind. Or maybe you'd like to race it.

If you run 5 miles (8.05 kilometers) regularly, you may be an intermediate runner. But if you've never run a marathon before, you're not ready to race a marathon until you've finished a marathon.

Training for a marathon involves stepping up both the intensity and the mileage of your "practice" runs. A carefully arranged, four-month-long program will train your body to run, and run fast, those 26.2 miles (42.16 kilometers), at the very top of your physical ability. This isn't just about crossing a marathon off your bucket list. It's about true athleticism and maybe even trying to win the thing.

You're not a novice, so you already know about interval running and training over months. Intermediate marathon training still takes a while -- around 16 to 20 weeks. But the plan is more than just long runs. It's about building in and adding intensity, speed bursts, and hills to your runs, which are various lengths (although many of them are, in fact, long). The weekly long run that you routinely do will increase as the training progresses, to adapt your body to the idea and strain of continuous, hours-long race-level running. This is supplemented with sustained tempo runs at high paces, rest periods, endurance tests and cross training, all of which promote aerobic strength and marathon-level pace setting.

Read on to learn how to set up a proper intermediate marathon training schedule.