Cross-training (CT): Cross-training activities allow you to give your joints and running muscles a break, while still working on building your endurance and strength. When the schedule calls for CT, do a cardio activity other than running (biking, swimming, elliptical trainer) at a moderate effort for 45 to 60 minutes. Strength-training, especially your lower body and core, is also very beneficial for long distance runners.

Tempo Run: Tempo runs help you develop your anaerobic threshold, which is critical for faster racing. For a 40-minute tempo run, for example, start your run with 5 to 10 minutes of easy running, then continue with 15 to 20 minutes of running at about your 10K to half-marathon pace. Finish with 5 to 10 minutes of cooling down. If you're not sure what your 10K or HM pace is, run at a pace that feels "comfortably hard."

Pace runs: After a 10-minute warm-up,5 run at your anticipated half-marathon pace for the designated mileage.

Interval workouts (IW): After a 10-minute warm-up, run 400 meters (one lap around most tracks) hard, then recover by jogging or walking 400 meters. For example, 3 x 400 would be three hard 400s, with a 400-meter recovery in between.6 You can also mix in 800-meter runs as well to mix things up.

Rest: Rest is critical to your recovery and injury prevention efforts, so don't ignore rest days. Your muscles actually build and repair themselves during your rest days. Fridays are a good day for rest since you will have run on Thursday and you'll have your longest run of the week on Saturday.

Saturday long runs: Run at a comfortable, conversational pace for the designated mileage. You can figure out the mileage of your outdoor routes with resources such as MapMyRun.com. Note that your long run does not have to be on Saturday. It can be whatever day works best for you.

Sundays: This is an active recovery day.8 Your run should be at an easy (EZ), comfortable pace, which helps loosen up your muscles and gets you more comfortable with running on fatigued legs.