So, you want to run a marathon? You can train to run a marathon in two months if you need to, but it is most optimal to have three months or 12 weeks or even 16 weeks, if possible. I trained to run the Boston Marathon in 10 weeks, and you can use this calendar for a 10-week marathon training plan too.
First, you need to decide which day of the week you are planning to do your long runs on. You will need to choose a day where you have a certain amount of free time -- between 1.5 hours (toward the beginning of your training) to 3-4 hours toward the end of your training. Typically, people pick Saturdays or Sundays as their long run days. If you pick Saturdays, Sunday will be your rest day every week. If you pick Sundays for your long runs, Mondays will be your rest day. That is how I did it, and it gave a reason to appreciate Monday mornings!
To start a 3-month marathon training plan, you should be able to jog at least 2-3 miles today. The key is in gradually increasing your distance, while working on increasing your speed during your shorter mid-week runs. If you can't run 2-3 miles today, you can still run a marathon. You'll just likely need a slightly longer training period -- say 4-5 months.
Start With a Slow Comfortable Pace
For your first week, on Tuesday, jog 2 miles at a slow pace. On Wednesday, jog 3 miles at a slow pace. On Friday, jog 3 miles at a slow pace. On Sunday, it's your slow long-distance run, so jog 4 miles at a very comfortable pace. To determine your comfortable pace, you should be able to carry on a conversation with a friend without becoming too out of breath. You'll be running a total of 12 miles that week.
For your second week, on Tuesday, jog 2 miles at a slow pace. On Wednesday, jog 4 miles at a slow pace. On Friday, jog 3 miles at a slow pace. On Sunday, it's your slow long-distance run, so jog 6 miles at a very comfortable pace. You'll be running a total of 15 miles that week.
Adding Tempo Runs and Fartleks
By your third week, to begin working on your pacing and speed, you'll want to be adding Tempo runs and Fartlek runs. Tempo runs are runs where you begin with a warm-up jog and then pick up the pace to your goal race pace and then wrap up with a cool-down jog. Fartlek is the Swedish word for "speed play", and those runs entail pushing yourself to alternate between your fast race pace and your slow comfortable pace on half-mile increments.
For your third week, on Tuesday, jog 3 miles at a slow pace. On Wednesday, go for a 4-mile Tempo Run (with a one-and-a-half-mile warm-up jog and then pick up the pace for the next mile to your goal race pace, then close it with a one-and-a-half mile cool-down jog). On Friday, go for a 3-mile Fartlek run (with a one mile warm-up jog, then pick up the pace for the next half mile as fast as you can, followed by a recovery half-mile at a slow pace, then another half mile as fast as you can, followed by a recovery half-mile at a slow cool-down pace). On Sunday, it's your slow long-distance run, so jog 8 miles at a very comfortable pace. You'll be running a total of 18 miles that week.
See calendar for Months 1-3: