How Many Miles in A Marathon: Weekly Mileage for Runners of All Levels

What if we told you that marathon training doesn’t have to be as daunting as it seems? I know, just thinking about how many miles in a marathon is a hefty thought – 26.2 miles is no walk in the park.

However, with the proper training plan and gradual improvements, everyone is capable of crossing that finish line. Whether it’s your first marathon, or you’re a certified marathoner getting back into your groove, the training is doable for people of all fitness levels.

Weekly Mileage for Marathon Training

In this article, we’re going to break down what weekly mileage will look like at different steps of your training in order to get you ready to run a marathon distance. For more general tips on developing your weekly mileage, check out this article.

Beginner Runners’ Weekly Mileage

If you are just beginning to run in general, you may find it more helpful to track minutes, not miles. Head out for a 20-minute run utilizing the Run/Walk Method and just get used to putting one foot in front of the other.

If you fall into this camp, give yourself plenty of time to make running regular and safe for you before upping that weekly mileage for marathon distance.

Try out a beginner running training plan and follow it closely. Consider even signing up for a 5K or 10K race just to experience race-day emotions. This way, you can start to build your marathon plans in a more tailored way.

Once you have given yourself one to two months of running regularly, try to find a marathon training plan that spans another four or five months at least. While this may seem like a major time commitment, spreading your training out in this way actually makes it far less of a commitment.

By following a gradual timeline, your training sessions will start to feel comfortable. Pushing the pace will be something you want to do, not something you have to do. And you’ll have some easy runs to fall back on and even everything out.

As you build your weekly mileage, note at the beginning what a “short,” “medium,” or “long” run is to you, and track how that changes over time. These changes are one of the most rewarding parts of being a beginner runner, because you’ll be surprised at how far you can run.

10 miles might have seemed impossible at the start, and in just a few short months that could be your medium distance run. Your body adapts, and if you take proper care of it, these adaptations will come naturally and easily. Over time, you will be ready for your race distance without even realizing it.

Intermediate Runners’ Weekly Mileage

For those who currently run, but have never run a full marathon, your training will look a bit different. Rather than starting with a beginner running training plan, you are likely ready to jump straight into a marathon training plan. Maybe you’ve even done a half marathon before, and having a training plan you can scale.

However, remember that your goal here will still be to build up your training. The jump from a half marathon to a full marathon can place a lot of stress on the body, so the improvements should still be gradual and planned. Nail down a training plan that factors this in.

As for your long runs, aim to squeeze in one 18-20 miler before the big race. Of course, this run will come near the race as you’ll need time to build up to it, and you’ll also need to leave yourself plenty of recovery time.

For your shorter runs, follow your training plan. No matter the distance of a given training run, keep your desired marathon pace in mind. Remember, any distance can be as hard or as easy as you want it to be. Mix up terrain, play with speed, practice your pace, and you will see improvements even with shorter mileage on many training sessions.

Advanced Runners’ Weekly Mileage

For advanced runners, the goal isn’t to make running regular anymore. If you’ve already done a marathon, there likely is less of a need to build your mileage.

However, it will always be a challenge getting to that marathon distance. The main goal of advanced runners’ training is taking their existing weekly mileage, whether it comes from a training plan or just love of the sport, and upping it to get you ready for those long-distance training runs.

How many 20+ mile long runs should I do?

No matter your running level when you start, as you near your marathon, take a crucial look at your training plan and make sure you agree with it.

Specifically, check out how many 20+ mile long-distance runs are included leading up to race day. If there are two many, there can be several drawbacks.

The Drawbacks of Too Many Miles

1. Injury

Long runs are a great training tool because they allow us to train on “tired legs.” This helps come race day, because the feeling won’t be totally foreign to us when we start to feel extreme muscle fatigue.

However, what happens when we run on tired legs? Usually, form and mechanics suffer. That’s just a fact. And while poor form in and of itself does not always lead to injury, it certainly exposes you to far more injuries than you would be subject to when running with proper form.

Our hips start to drop down towards the ground, our knees start to buckle in, and the effects of these form mistakes compound as you keep running. Most studies show that running beyond three hours, no matter the distance, dramatically increases recovery time. So, no matter what your long run distance is, consider capping it at three hours.

2. Burnout

Believe it or not, training too much can actually hurt your marathon time. If you’ve pushed yourself too hard on too many long runs before your race, you might be mentally burned out come race day.

​You’ll lack the motivation required to push your pace and cross that finish line at your desired time. Don’t get me wrong, you need to be ready to run long distance for your marathon. But you want to approach that starting line hungry. Too many long training runs will just leave you fatigued and diminish the hunger you once had to crush your race.

3. Distraction

Think about all the mental energy and the time you spend gearing up for race day, and then recovering after. If you have too many runs of that distance or something close to that distance, you are taking away too much time from the rest of your life.

Training and recovering from these body-beating long runs will become your only focus.

To run a successful marathon, you need to remain a well-rounded person through training and race day. And it won’t just take away from other areas of your life, it will diminish your running training as well.

Too many long runs and you won’t have enough time for vital pieces of training. This includes strength training, speed workouts, form drills, and mobility work crucial to better you as a runner.

So, what does that mean for me?

The 18-20 mile run is a major piece of many marathon training plans. Years of athletes tinkering with this number has led to its popularity. However, note that nothing is set in stone here.

For beginner runners, as described above, a gradual build is key. Your first long run might be 5 miles. From there, try to work up to 7, and then 10, etc. as far as running mileage.

Work in incremental increases until you can tackle an 18-20 mile long run, but don’t skip any steps to get there. Note that this may take a while, but aim to get in one 18-20 mile run before race day.

Do consider capping your run at that three-hour mark no matter what though, just to make recovery easier on yourself.

For advanced long distance runners, 18-20 might not feel like enough for you. However, we urge you to remember the drawbacks of too many long runs mentioned above. Moreover, you can make your 18-20 as tough as you’d like.

For example, you can try a progressive long run where you are getting faster the whole time.

On the other hand, you can tire out your legs at the beginning of your run with some Fartleks or other speed drills, in order to practice most of your mileage on tired legs.

And if you’re really looking for a different stimulus, consider training for more of an ultramarathon.

Maybe you want to start training for a 50K to shake things up and push that running mileage. But for marathon training, that might not be the right idea.

Remember the goal of your training is to find your edge, not to cross it.