The long run – Distance, pace and build up

The long run – Distance, pace and build up

Kim Petersen By Kim Petersen


The long-run is the cornerstone of every excellent marathon training program. But, how far should the long run be, what tempo should you run, and how do you train the long run over a 12-20 week training program?

If you don’t put enough kilometres in your legs, you risk the last 12 kilometres of the marathon being insufferable. Vice versa, when you run too far in the long run, you risk injuries and fatigue, so you are left with a body as heavy as lead at the start line.

Therefore it is essential to hit both length and tempo right on the long run to be successful, so you can optimize your marathon shape and avoid injuries.


Overview of the article    

1. The Long-run - A short definition

2. Why is the long run necessary?

3. This is how far you need to run on the long run

4. The pace on the long run

5. 5 Variants to the long run

6. Strategy for building the long run

7. The Alternative to the long run


The Long-run - A short definition

The first thing we should look at is how we define the long run. How many kilometres should the long run be before calling it a “long” run?

Sadly there isn’t any consensus about it, neither among scientists or coaches. It is, therefore, up to the individual to decide what the word “long” means. I think in context with a marathon, the long run is over 25 kilometres. Plenty of marathon programs peaks at 32 kilometres as the longest runs, or 2.5-3 hours if you run by time.

The famous American coach Jack Daniels writes in his book “Running Formula” that first-time marathon runners shouldn’t run more than 2.5 hours. The hypothesis behind the statement is that first-time marathon runners won’t benefit from training longer.

For the more experienced marathon runners, some coaches suggest distances up to 40 kilometres. If we look at elite marathon runner’s training by time, a somewhat similar pattern appears. The long-run, over 30 km, is an occurring part of their training.


Success without the long run?

Of course! Some stories exist about elite marathon runners and other well-trained marathon runners from Denmark, and abroad that ran incredible marathons without runs over 20 kilometres. E.g. England’s Jim Peters, whom in 1951 clocked in at 2.29 (4 minutes slower than the former world record) with his longest run being 24 kilometres. In recent times, the Norwegian Grethe Waitz won New York Marathon in 1979 without any training runs over 20 kilometres.

In Denmark, the Aarhusian, Peder Troldborg (2:23:48 at marathon distance) practically became nationally known in running groups for not running longer than 14-15 km on his longest runs before a marathon.



Why is the long run necessary?

To learn more about the long run and why we should or shouldn’t run the long run, we need to look at the benefits of the long run;

• Strengthens our bones, joints, ligaments and muscles so it can tolerate the enormous strain a marathon has on the body

• The body adapts to using fat as an energy source because the carbohydrate depots deplete

• We gain a mental adjustment, making us able to keep focus during the entire marathon

• Increasement in number of capillaries, meaning we get a better flux of nutrients into the muscle, and the waste products away from the muscle

• We train the brain and nervous system to send signals to the muscles

• We train our fast muscle fibres to take over for our slow muscle fibres at the end of the marathon


The long run has several positive adjustments, but there is another side to the story.


Long runs


Long runs are tough

The long run can be tough for your body, needing multiple days to recover properly after an over 30 kilometres run.

If you at the same time are going to train substantially the week after, the risk of getting in a state where the body has troubles recovering is high, with the risk of overtraining and thus a deteriorating performance ability. Often it is due to running the long run at a slow pace, at which you risk your running technique because your biomechanics are changing when you slow down during the run. Therefore, running technically inappropriate.

During your long runs, you should incorporate a period with faster runs. However, it will entail that the overall strain increases, and with it, the risk of overload injuries goes up as well.

To accommodate these problems, making the long runs shorter would be a solution.



This is how far you need to run on the long run

Based on what we empirically and scientifically know about the long run, in my opinion, we need to make a distinction between experienced runners and first – or second-time marathon runners.

For debut marathon runners, I recommend running 2-3 long runs between 25-32 kilometres.

Longer runs only will prolong your recovery time, and it is uncertain whether or not it will pay off running up to 35 kilometres.

As first time runner, you need to adjust the body to the hardships – not least mentally! Therefore, you need to be serious about the long runs!


Run after personal preferences as an experienced runner

As the more experienced runner, it is up to personal preferences. 

Have you trained for years, your body already adjusted for the enormous strain the thousands of hours on the road caused.

Therefore, you can, in my opinion, run excellent marathons without completing training runs over 20 kilometres if you instead focus on the quality of training.

You should still include training runs that are 30 kilometres long if you want to maximize your marathon potential.

It may be that marathon legends like Grethe Waitz and Jim Peters ran incredible marathons with relatively little training. But it is important to point out that Peters ran 12 minutes faster after increasing the long run training. Grethe Waitz was also known for doing large amounts of exercise (but not the highest compared with other marathon runners). Later in her career, the long run became a regular part of her marathon training.

In modern marathon training, international elite runners - almost with no exceptions - runs longer than 30 kilometres on the long run.



The pace on the long run

Are there not enough knowledge about how long you should run on your long runs? Then there is even less knowledge about how fast you should run your long runs.

Since there are no scientific studies on the subject, we need to check out successful trainers approach throughout time.

In recent times the consensus was running the long run as close to the desired marathon time as possible – preferably at the end of your training course. There is referred to 3-8 weeks before your marathon due to downsizing the last three weeks when talking about the end.


The reason why you should train close to your desired marathon pace

The closer to your desired marathon pace you run on the long run, the more specific you are training. You are specifically setting your energy conversion, nervous system and muscles to operate at your desired marathon pace.

Should you run at a much slower pace than what you desire for the marathon during the long run, you don’t get the same strain to the circuit, nervous system and muscles. Your body doesn’t learn to run at a high pace – but “only” far.

The disadvantage of training at a high pace is a high energy demand, of course. For example, if you run your long runs at marathon pace every week, it deteriorates the body quite a bit.

Finally, you can’t start training by running 25 km or more at your planned marathon pace. Therefore, you need different variants to the long-run, so you can alternate the intensity and thus the strain.



5 variants to the long run

There are five variants to the long run, which I use in the training programs I plan. The workouts are listed after intensity.

1. The light paced long run: 90 to 150 min. Pace 80-90% of marathon pace

2. The progressive long run: 15-28 km. Pace: 80-102.5% of marathon pace

3. The long run with 20-60 min at marathon pace: 90-150 min. Pace: 80-100% of marathon pace

4. Marathon intervals: 3-8 km intervals. Total of 15-25km. Pace 95-102.5% of marathon pace

5. The long specified run: 15-28 km. Pace: 95-100% of marathon pace


The end goal is running a long run between 25-30 km at marathon pace approximately 4-6 weeks before your marathon.

But how do you get there? For this, you need a strategy for building up the long run.


Long runs


Strategy for building the long run

Several excellent reasons exist as to why you should build up the long run over multiple months. I will shortly describe the five most important reasons (in my opinion).

1. You avoid monotone training. Monotone training kills the joy of running and form development

2. You have ensured a progression in your training, resulting in significantly better results.

3. Your body adjusts to the load, and the risk of overload injuries minimizes.

4. If you remember to downsize in training 3-4 weeks before the marathon, your peak will hit at the right time.

5. You gain confidence by seeing improvement in your training.


Here’s an example of how you can build up the long run over 20 weeks (last 4 weeks = downsizing).


Here’s how you build up the long run over 20 weeks

You start building with a starting point at 15-18 km.

In the coming weeks, slowly add 2-3 kilometres extra on the long run until you reach 90-95% of the maximum number of kilometres you wish to run on the long run throughout the training period.

Hopefully, it should happen within weeks 5-8, depending on if we increased with 2 or 3 kilometres each week and if we started at 15 or 18 kilometres.

For now, the pace should primarily be steady – approximately 80-90% of your marathon pace – corresponding to about 30-60 seconds slower for most runners.

In this period you should solely focus on increasing the amount of training. The extra workload will appear by increasing the length of the long run.

If your legs aren’t tired, you can add about 15-20 min around your marathon pace. I would recommend reducing the length of the long run one time every four weeks, so your body gets a chance to keep up with the development.


Increase the pace on the long run

When you reach 90-95% of the maximum amount of kilometres for the training period, start increasing the long-run pace. Now you can insert shorter periods with running at marathon pace or use some of the variants I wrote in the section “5 variants to the long run”.

To ensure the collective training load doesn’t get too big too early in the training period, you need to reduce the number of long runs. I.e. you run 20-22 kilometres in the first week with increasing the pace.

In the coming weeks, the choice is yours to maintain a total number of kilometres around 20-25 kilometres, where you slowly increase the amount of training around marathon pace.

During weeks 12-16, you should reach the maximum training load, meaning you reach the maximum amount of kilometres on the long run, and at least 2/3 of the run is in marathon pace.

Utilize the more intensive variants of the long run, but don’t forget the easier variants, so you don't wear down your body.


Example of building the long run:

Long runs


Training after pulse or feel

If you don’t know your marathon pace and want to run after your pulse or feel, here are some guidelines you can need:

- 80-90% of marathon pace corresponds to under 75% of your max pulse or very easy.

- 90-100% of marathon pace corresponds to about 75-85% of max pulse or easy to steady.


Example: If your target is to run a marathon in 4 hours

If your goal is to run a marathon in under 4 hours, then;

- 100% of your marathon pace 5 min 41 sec pr. km

- 80% is 6:49 min pr. km and 90% is 6:15 min pr. km


Use this excel spreadsheet to calculate your training pace if you know your finish time. Or use the formula: Training pace = Desired marathon pace * (2 – % of marathon pace / 100)

In this example, the math would be: Training pace = 5:41 * (2 – 80 / 100).


The post about the long run ends here, but here is something extra for the curious running souls…


Long runs


The alternative to the long run

If you want to become a great marathon runner, there is no way around the long runs, but there is a fantastic alternative to the long workouts.

You can split up the long run into two shorter runs and achieve an excellent workout effect if you do it right!

But why split up the long run into two shorter runs?

As I see it, there are only two reasons why you should consider splitting your long run into two shorter runs – on the same day.

1. You want to run multiple kilometres with high intensity

2. You want to achieve a larger amount of training on the day


Reasons such as lack of time and/or you want to skip the long exhausting runs may be valid. But it isn’t the entry angle for becoming a better runner.


How you shouldn’t approach the two short runs

You are invited to a birthday, and you are tired of running the long runs.

Instead of running 25 kilometres during the morning, you decide to run 12.5 km during the morning, and when you get home in the afternoon, you run an additional 12.5 km, while the pace is the same as the long run.

By dividing the long run over this way, the total amount of training stimuli is substantially less because you ran the last 12.5 km after recovering and had loaded the energy depots.

Thereby you don’t achieve the same training effect as the 25 km run, where you force the body to run the last 5-6 kilometres in a slightly exhausted state.


How you should approach the two short runs

• Increase your pace, so the average pace is higher for the two runs than for the long run

• Increase the total training amount on the two runs compared to your long run

• You can also choose both


Instead of running 25 km at a pace equivalent to 5:00 min pr. km, you run the two shorter runs at a faster pace than the long run. E.g. you run 15 km at 4:45 min pr. km during the morning and 10 km at 4:30 min pr. km during the evening.

In total, you ran 25 km at a significantly faster pace, and because you managed to recover a bit between the two workouts, you can maintain the pace for the last 10 km. Thereby you get better quality training – and most importantly, your recovery time after two runs should match the recovery time after the long run.

You can also choose to split the long run to increase the total training amount. In the example with 25 km, you could choose between breaking the long run into 2 x 14 km and achieving a total of 28 km.

Your recovery time would probably be the same in both scenarios.


Recovery between the two short runs

One of the things to consider is how you handle the break between the two workout – especially concerning dietary intake.

No matter what, I recommend digesting some between the two workouts, but how much to digest depends on what you want to achieve from the training.


Focus on training amount

It is definitely the hardest to run workout no. 2 with a limited energy intake after workout no. 1. Therefore, this strategy primarily is recommended when focusing on the amount of training.


Focus on a higher pace

Is the strategy to temporarily increasing the pace of the workout, I recommend a regular energy intake. When running workout no. 2, it helps being energized, especially if you choose to run the last workout faster than the first.

When you get into great shape, you can limit your energy intake between the two workouts – even as you increase the workout's pace – to “replicate” the scenario of a marathon to your body.

This strategy is primarily for experienced marathon runners.


The practicalities of organizing training

Suppose you want to vary your long run with the so-called double passes, i.e. 2 shorter runs on the same day. Here are 5 variations to the double pass you can do.

Instead of going for one long run of 25 kilometres at 5:00 min pr. km (marathon pace is, e.g. 4:45 min pr. km), you can split the run into as followed,

1. The “easy one”: 1. 15 km light run at 5:00 min pr. km + 2. 10 km steady run at 4:45 min pr. km (marathon pace).

2. The “long one”: 1. 15 km light run at 5:00 min pr. km + 2. 15 km easy run at 5:00

3. The “semi-tough one”: 1. 15 km run incl. 30-35 min at 4:30 + 2. 10 km run incl. 5 x 3 min at 4:00 <3 min="" jog="">

4. The “tough one”: 1. 18 km light run incl. 60 min at 4:45 + 2. 10 km run incl. 4 x 5 min at 4:30 <2 min="" jog="">

5. The “challenge”: 1. 12 km run incl. 6 x 3 min at 4:00 <2½min jog> + 2. 18 km run incl. 60 min at 4:35-4:40


However, I would not recommend consistently replacing the long run with the double pass. Do that 2-3 times during the 20 week training period to achieve variation in your training when you need an extra kick.

Use the 2 first suggesting during the first 8-10 weeks and the last 3 suggestions during the weeks you train the most, and the shape is appearing.

I recommend running respectively before dinner / afternoon, e.g. 10.00 / 17.00. This scenario lines up with dinner times, making it easier to optimize your energy intake after the two runs.


Enjoy running!



More inspiration?

Find additional articles in our inspiration universe right here:

Inspiration and articles


  • The best running shoes for long runs

    Here you will find the best running shoes for a long run. The list includes both neutral and stable running shoes. See more here. 

  • The best Asics running shoes 2021

    See the list of the best Asics running shoes whose well-know fit and comfort is very popular among many runner. Read more! 

  • REVIEW: Havit Fitness Tracker - Simple affordable activity tracker

    We have tested the Havit Fitness Tracker H1108A, which is a simple activity tracker in a classic design. Read the review here. 

  • The best HOKA ONE ONE running shoes in 2021 - See the entire list here

    HOKA ONE ONE shoes are known for their maximum shock absorption, minimal weight and low heel drop. Read on for an overview of the best HOKA running shoes!