Interested in Building Up Mileage? Here's the Twelve-Mile Run Plan.

The chart below is a 12-week plan to build up to a half-marathon. It is not designed for beginners, but rather intermediate runners who already run 10-15 miles a week.

The focus is to run shorter and faster runs during the week and a long, slower run at a comfortable pace on the weekend. Eventually, the two methods should meet, and your longer, slower pace is actually faster than before.

Run #1: Fast-paced run (usually 1-4 miles)

Run #2: Interval runs. Break up the distance into quarter-, half- and one-mile repeats (your choice of pace and distance). Mix in some leg PT on any runs that you do that are quarter- and half-mile repeats: For instance:

Repeat 3-4 times.

• Run a half-mile or quarter-mile at your goal pace.

• Squats 20

• Lunges 10/leg

Run #3: Fast-paced run (usually 1-5 miles)

Run #4: Optional non-impact day or run the distance listed (regular pace)

Option #1 

• Swim 1,000-1,500 meters (any stroke)

• Try 100, 200, 300, 400 and 500 meters = 1,500 meters

Option #2: Hypoxic pyramid

2, 4, 6, 8, 10, 12, 10, 8, 6, 4, 2 x 100 meters

Option #3: Lifecycle bike pyramid

Manual mode/levels 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 until failure. Repeat in reverse order, holding each level for one minute.

Run #5: The long pace run (usually done on the weekend).

Stew Smith is a former Navy SEAL and fitness author certified as a Strength and Conditioning Specialist (CSCS) with the National Strength and Conditioning Association. Visit his Fitness eBook store if you're looking to start a workout program to create a healthy lifestyle. Send your fitness questions to stew@stewsmith.com.

Want to Learn More About Military Life?

Whether you're thinking of joining the military, looking for fitness and basic training tips, or keeping up with military life and benefits, Military.com has you covered. Subscribe to Military.com to have military news, updates and resources delivered directly to your inbox.