Splitting Long Runs: Is It OK To Split Up My Long Runs?

Almost all marathon runners have the same anxiety when they look at their marathon training plan: the long run.

The notion of running several hours or upwards of 20 miles can be extremely daunting. For this reason, splitting up long runs for marathon training can be an appealing alternative.

But, is it OK to split up long runs for marathon training? Will splitting long runs into two shorter marathon training runs offer you the same benefits as a marathon long run?

In this guide, we will discuss what it means to split up long runs for marathon training, the pros and cons of splitting long runs, and tips for how to split marathon long runs to minimize the consequences and maximize the benefits of dividing long runs into separate runs.

We will look at: 

  • What Does It Mean to Split Up Long Runs In Marathon Training?
  • Is It OK To Split Up My Long Runs?
  • Pros and Cons of Splitting Long Runs
  • Tips for Splitting Long Runs

Let’s get started!

A runner running their long run.

What Does It Mean to Split Up In Long Runs Marathon Training?

Splitting up marathon training long runs means that instead of following your marathon training schedule and running the full long run distance in one continuous workout without stopping, you do two shorter runs that total the same long run distance.

For example, imagine that your marathon training plan calls for 18 miles on Sunday, and you have to take your kids to soccer practice early in the morning, and there’s no way that you can get in those 18 miles.

Instead, you might split up an 18-mile long run by running 10 miles in the morning before your family obligations and then 8 miles before dinner once you are home from soccer practice and the various activities of the day.

There are different ways to split long runs. s

Some people run half or part of the long run distance in the morning and then run the remaining mileage in the afternoon or evening, as just described, while some runners split up long runs over two days by actually doing part of it on one day and then the remaining mileage the next day.

There are pros and cons to both ways of splitting long runs during marathon training. We will address the benefits and drawbacks of splitting long runs for marathon training in upcoming sections.

A person running their long run on the beach.

Is It OK To Split Up My Long Runs?

Even runners training for shorter distances like the 10K and half marathon often ask if splitting up the long runs on the training schedule is OK.

After all, particularly with marathon training, once the long runs start to get up to 18 or 20 miles, you may be running for 3 to 4 hours, depending on your marathon training pace and ability level.

With busy lives, family commitments, and even just the struggle of mustering the motivation to run for 3 to 4 hours, it becomes all the more appealing to potentially split up a long run into two separate runs, the total of the same long run distance.

There are various reasons why runners may split long runs up into multiple workouts. The most common include the following:

  • Logistics of fitting in long runs based on your schedule
  • Inclement weather
  • Lack of motivation
  • Traveling or inability to find a suitable long run route
  • Illness, muscle cramps, chafing, possible injury, blisters, or other discomfort when you start out a long run, so you truncate and then hope to finish the long run distance and a separate workout
A person running.

The short answer to “Can I split up my marathon long runs?” is yes—you certainly can break up long runs on your training schedule.

There are no rules or “marathon training police “ that will force you to run your long runs in one continuous run or follow your marathon training plan to a T.

However, by and large, it is best not to split up your long runs, especially not frequently.

Occasionally, splitting long runs into two distinct workouts is fine and may even have some benefits, but relying on split long runs as a standard practice instead of following your training plan long run distance as written is going to shortchange your potential.

Splitting a long run negates the benefits of long runs and the entire purpose of long runs for marathon training or preparing for any long-distance race.

A person running their long run.

Pros and Cons of Splitting Long Runs

There are various pros and cons of splitting long runs and understanding the benefits and the downsides will help you determine whether you should follow your marathon training plan long runs as written or split long runs into two separate workouts.

Benefits of Splitting Up Marathon Long Runs

As mentioned, there are several reasons why runners may split up marathon training long runs into two different workouts that may provide certain benefits:

Cuts Back On Injury Risk

Injury-prone runners often find that splitting up long runs cuts back on the risk of injuries because you are building in more recovery time and accumulating less fatigue and microscopic damage to your bones, muscles, joints, and connective tissues.

More Motivating

When there is bad weather, or you have to do a long run on a treadmill, splitting up a long run can be more fireable from a motivational standpoint.

A person running their long run

More Feasible

Splitting up long runs is often more logistically feasible if you have a tight schedule, are traveling, or need to run in the dark.

Potential to Run at a Faster Pace

Splitting up long runs may allow you to do your long runs at a faster pace because you are not running as far without stopping.

Decreases Recovery Time

The main benefit of splitting long runs is decreasing recovery time relative to long runs completed in one continuous nonstop run.

This means you can bounce back faster after your weekly long run and recover quickly for your next hard workout if you run two medium-long runs rather than one super long run.

A group of people running in the road.

Downsides of Splitting Up Long Runs

Understanding why you shouldn’t split up long runs centers around understanding the benefits of long runs on a marathon training plan.

The primary objectives of the long run are to increase physical and mental endurance, increase blood volume, strengthen the cardiovascular system, help your body adapt to higher mileage and a longer time of your feet, and develop your aerobic base.

Essentially, marathon training long runs are the closest replication to running the marathon race that you will experience in training and, therefore, serve a key role in preparing your body and mind for running 26.2 miles on race day.

Long runs strengthen and improve the efficiency of the cardiovascular system and strengthen the heart muscle, which then increases stroke volume.

This enables the heart to pump more blood—and thus oxygen—out to the body every time it beats. This can effectively reduce heart rate because the heart becomes more efficient.

Two people running their long run

Capillary density increases, allowing for better perfusion of working muscles, and blood volume increases over time. 

These adaptations, in turn, also increase stroke volume, cardiac output, oxygen transport and delivery, and, ultimately, VO2 max

Long runs also increase the mitochondrial density in skeletal muscles, particularly in Type I muscle fibers, and improve your ability to burn fat for fuel (rather than stored glycogen) at higher intensities.

Additionally, long runs are your “dress rehearsal“ for your marathon race in that they are a great opportunity to practice your fueling, work on your pacing, hone your mental strength to stay focused and tough when you start to get bored or tired, try out different running shoes and outfits to make sure that you do not experience any chafing or pain, etc. 

Splitting up long runs robs you of this opportunity, particularly in terms of practicing your fueling and hydration for your marathons.

Tips for Splitting Long Runs

If you decide that you do want to split up marathon training long runs into two different shorter runs, here are some tips:

  • Only split up long runs occasionally rather than all of your marathon training plan long runs so that you still get some of the benefits of doing long runs without stopping.
  • Split up shorter long runs rather than your 20-mile long runs.

You can find all of our free marathon training plans here.

A person running their long run
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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