Determining how long to train for a marathon is an important decision that is often overlooked. In most cases, runners find a marathon training plan they like and then settle for the pre-determined length.
However, taking the time to first determine how long you should train for a marathon and then searching for a training plan will set you up for maximum success.
How long should you train for a marathon?
The time it takes to train for a marathon varies from one runner to the next. Most seasoned distance runners can successfully train for a marathon in 16-20 weeks, with some advanced athletes requiring as little as 12 weeks.
Non-runners, beginners and first time marathoners often require a bit more than this pre-set length. Brand-new runners will benefit from 6+ months of training, with first time marathon runners sometimes requiring 4-6 months.
Runners who have completed a marathon in the past but taken a significant amount of time off may still require some extra time to train as well.
Why does it take some runners longer to train for a marathon?
How long it takes to train for a marathon varies from one runner to the next primarily based on fitness level. Your current training and past experience also play a large role in the length of time your training will take.
Many new runners train for 10ks and half marathons on their way to a full marathon, making their total training time much more lengthy as well.
Variables that Influence How Long It Takes to Train for a Marathon
There are quite a few factors that influence how long you should train for a marathon. Some of the main variables that play a role in how long it takes to train for a marathon are the following:
- Current fitness level
- Past running experience
- Commitment level
- Base training leading up to starting point
- Lifestyle
- Available time for training
- Pre-existing health conditions
- Tendency to get injured or lingering injuries
Why is it important to know how long to train for a marathon?
Many runners overlook the fact that each individual requires a different amount of time to train for a marathon. Conforming to the “standard” marathon training plan length may limit your progress over time.
Follow too short of a training plan and you might find yourself undertrained and hitting the wall on race day. On the other hand, training for too long of a time leads to overtraining, which might hinder recovery or make you more prone to injuries.
Knowing your own body, its strengths and weaknesses, as well as being honest about your current fitness and past progress all are important when it comes to determining your training length.

How Long Does It Take to Train for a Marathon
Here are some guidelines for how long it takes to train for a marathon based on skill level and running experience. Use these timeframes in addition to your own insights and knowledge about your health and body to guide you as you choose or create a marathon training schedule.
Brand-New Runners
For those who have never run before – whether you are physically fit but have never used running for exercise, or are a self-proclaimed “couch potato” – marathon training will take you a bit longer. Having zero running experience requires a few extra months of base training before long runs can increase to a marathon training length.
In this case, it will take about 6 months to train for a marathon. During this time, you’ll build up base mileage in the first 1-2 months before increasing long runs for the last 4 months to peak at 20 miles.
>> Download this Couch to Marathon 6 Month Training Plan for free!
Beginner Runners
Those who have been running consistently for a few months but never increased mileage to more than a 5k are in a great position to build fitness. Beginner runners have often already begun to lay some of the foundational layers of marathon training, and just need a bit of extra time to get ready for the distance.
In this case, it takes about 5-6 months to train for a marathon. Depending on how long you’ve been running short distances, you’ll need a little extra time to continue before increasing long runs.
>> Learn how to train for a marathon in 6 months
Intermediate Runners
Most recreational runners consider themselves to be an intermediate runner. Those who have completed races from 10ks to half marathons and even some marathons often fall into this category.
If you have been running for some time but never put any serious effort into your training and PRs, you likely are still ready for a “typical” marathon training plan length of 16-20 weeks. During this time you’ll continue running consistently while increasing weekly long run mileage to prepare for race day.
>> Download this Marathon Training Plan for Intermediate Runners
Advanced Runners
The most experienced runners are often training at a marathon level throughout the year. In this case, they can usually tailor their training for specific goals without requiring any extra base fitness.
Most advanced and elite runners can train for a marathon in 12-16 weeks.
Regardless of the category in which you land, remember the advice listed for how long it takes to train for a marathon is simply a guideline. Each runner will need to listen to their body and adjust based on unique circumstances and conditions.
Taking the time to learn and plan for how long it takes to train for a marathon will set you up for optimal success on race day. You’ll avoid overtraining, burnout and prepare to conquer the wall on race day.