Found on Competitor.com and written by Jason Fitzgerald
The marathon is a difficult distance—there’s no doubt about that. At 26.2 miles, it is considered the most difficult road race because of its sheer length.
That distance creates more muscle trauma (including your heart!), higher levels of fatigue, and greater damage to the endocrine system than shorter races. But while this is all temporary, a challenging race like a marathon should be approached in a methodical, strategic way to ensure that injuries are kept to a minimum and the chances for success are maximized.

Timing clock at finish line of marathon race with runners crossing finish line
Unfortunately, a lot of runners sabotage their efforts by rushing their training. And rushed training is risky training!
Depending on your fitness level, goals and ability, you’ll need between 12 and 20 weeks to prepare for the challenges of racing 26.2 miles.
Let’s find out where you are within that range.
“I’m a beginner!”
Those with a relatively low fitness level need more time to train for a marathon—and that does not mean just beginner runners. Even a highly trained competitive marathoner needs more time to prepare for 26.2 miles if they have taken an extended time off from running.
The commonality between a beginner and an out-of-shape competitive runner is their low fitness level.
If you can run about 8-10 miles for your long run, you’ll need between 18-20 weeks to adequately prepare to run a marathon. This ensures that there is enough time to carefully build your overall mileage and long run to a level that will support a marathon on race day. Runners at this level should focus on finishing the race and not on a specific time goal.
But what if you’re running less than 8 miles for your longest run of the week? In that case, you’re not ready to train for a marathon. Focus on a half marathon and come back in 4-5 months.
“I’m an Intermediate Runner!”
Runners with a medium level of fitness are those who are comfortable running about 25-35 miles per week with a double-digit long run. If that describes you, dedicate between 14-18 weeks of training solely to the marathon.
Intermediate runners are not as worried about getting their long run up to about 20 miles before the race. There’s plenty of time for that. Instead, the goal now becomes performance—or in other words, a specific time goal.
These runners will first build their long run distances up to about 20 miles. But then their long runs can alternate between 18-20 miles, while shorter long runs can include some goal marathon-pace running.
Here’s an example progression of long runs over the last four weeks of peak marathon training:
- 20 miles – easy pace
- 16 miles – first 12 miles at easy pace, last 4 miles at goal marathon pace
- 20 miles – easy pace
- 18 miles – first 13 miles at easy pace, last 5 miles at goal marathon pace
This approach prioritizes both general endurance and marathon-specific endurance. It will help you run as fast as possible on race day.
“I’m an Advanced Runner!”
Runners with an advanced fitness level are comfortable running over 40 miles per week with a long run in the 12-15 mile range. Since they’re already in great shape, they don’t need as much time to specifically train for a marathon.
An effective training approach for this type of runner will include about 12-16 weeks of specific marathon training. The first half of the training program will help the athlete get up to 20 miles for their long run. The second half of the plan will include more pace-specific long runs.
Here’s an example progression of long runs over the last 6 weeks of peak marathon training:
- 20 miles – easy pace
- 18 miles –first 14 miles at easy pace, last 4 miles at goal marathon pace
- 21 miles – easy pace
- 20 miles – first 15 miles at easy pace, last 5 miles at goal marathon pace
- 18 miles – first 10 miles at easy pace, last 8 miles at goal marathon pace
You’ll see that for every ability level, the goals remain the same. Run more consistent long runs with an increasing amount of the volume at goal pace. The more advanced the runner, the more mileage and goal pace they can handle. And ultimately, the faster they’ll run.
No matter what type of marathoner you are, always work on your ability to run higher mileage. It will increase your workload capacity, which has the most direct impact on your race times.
Now lace up those shoes and start running long!