There is no single correct number of weeks for marathon training. Your race date sets the deadline, but your recent training determines the starting point. Depending on your current consistency, long-run history and time available, the right first phase may be base building, maintenance or marathon-specific preparation.
Signing up for a marathon does not automatically mean you should start marathon-specific training tomorrow.
Two runners can enter the same race on the same day and need completely different first weeks. The difference is not motivation. It is the training base they bring to the start of the process.
That is why choosing a marathon does not automatically mean you are ready to start marathon-specific preparation.
The calendar is only half the question
Most marathon plans have a defined duration, but there is no universal number of weeks. Current plans in the market range widely. From 12 to 20 weeks.
Those numbers are useful for structuring training, but they do not answer the first question a runner should ask:
What training is appropriate for me now, given where I am today and how much time I have before race day?
Imagine two runners preparing for the same marathon. One has been running four times a week for the past year, with consistent weekly volume and regular long runs. The other has plenty of running experience but has trained inconsistently over the past few months.
Their destination is identical. Their appropriate starting point is not.
Research in recreational marathon runners supports the importance of looking beyond the race date. Training volume, frequency and longer endurance runs are associated with marathon performance, which means the training you have already accumulated matters when deciding what should come next.
More time does not necessarily mean more marathon-specific preparation
Suppose you decide on your marathon 30 weeks before race day. That does not mean you need 30 weeks of progressively harder marathon training.
You may benefit from first building a more consistent running base. If you are already in a strong place, the sensible choice may be to maintain that level for a period before more specific marathon work begins.
The extra time is valuable because it gives you options.
The opposite situation is just as important. If you choose a marathon with 14 weeks remaining, the calendar cannot create a training base that is not there. If your recent running supports moving directly into marathon-specific preparation, that may be appropriate. If it does not, simply squeezing a longer standard plan into the available weeks does not solve the problem.
Three starting points, depending on where you are
That can lead to three broadly different beginnings.
Build-up. Your first priority is to develop the consistency and training base needed before marathon-specific work becomes appropriate.
Maintenance. You already have a solid base, but there is enough time before race day that more specific marathon preparation does not need to begin yet.
Marathon-specific preparation. Your recent training and current capacity provide the basis to start the more specific work leading towards the race.
None of these says anything about whether you are a “good” or “bad” runner. They simply use the time available differently.
Start with where you are
This is why SmartRunning does not automatically place every runner into the same type of marathon plan as soon as a race date is entered.
The race date establishes the time available. Your current capacity and recent training help determine where the preparation should begin. From there, the training can be built towards the same destination in a way that makes sense for you.
Same marathon goal. Different starting point. Different journey.
See how SmartRunning starts from your recent training, current capacity and time to race day.