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How Long Should Your Longest Marathon Training Run Be?

Many runners find themselves feeling a little overwhelmed as they begin marathon training. It’s hard to imagine completing 26.2 miles when your training never takes you to that distance – especially during your long runs.

The longest run before a marathon is usually quite a few miles shorter than the actual race distance itself.

How long should your longest run be during marathon training?

Before training to run a marathon, it’s easy to assume that the mileage will continue to increase until you build up to 26 miles. However, most distance runners know that marathon training rarely involves running more than 20 miles at one time.

Related: 9 Things to Know Before Training for a Marathon

Whether you’re designing your own marathon training plan or just looking for a little confirmation that the plan you have will adequately prepare you for race day – understanding marathon training long runs will help set you up for success.

You might find yourself downloading a highly rated marathon training plan, only to discover than the longest run is only 20 miles – or maybe 16 miles, 18 miles, or even 22.

Deciding how long your longest run should be during marathon training involves a few different factors.

Understanding how far your marathon training long runs should be is key to success on race day. Here is what you need to know about long distance running to get you through any full marathon training schedule. #marathontraining #longruns #longdistancerunning

How far should your longest run before a marathon be?

Some factors to consider:

Your longest run during marathon training may vary from one training cycle to the next depending on your goals, type of training, and current physical abilities.

In general, a pretty standard guideline to follow is that the longest run during marathon training should last no longer than 3.5 hours.

Many new runners assume that their marathon training long runs will peak at 20 miles – and then find themselves surprised to see plans that cap mileage at 16 miles, or continue up to 22 or even 24 miles.

Related: 15 Things I Wish I Knew Before My First Marathon

Marathon training looks different for every runner. Some runners are able to complete a 20 mile long run (or even the entire marathon) in well under 3.5 hours, while others would be on their feet for well over 4 hours just to finish the distance.

How far do you really need to run to train for a marathon?

Ultimately, the answer varies depending on the runner. Long runs are the staple of marathon training, and gradually increasing your long run distance each week is key to most marathon training plans.

The longest run before a marathon usually occurs about 4 weeks before race day, when mileage peaks.

Understanding how far your marathon training long runs should be is key to success on race day. Here is what you need to know about long distance running to get you through any full marathon training schedule. #marathontraining #longruns #longdistancerunning

This long run should last between 3-3.5 hours, but should be at least 16 miles in length, regardless of your running speed.

Long runs that are longer than 20 miles are usually unnecessary unless you are following a specific high mileage training program or running at an elite level.

Why isn’t the longest training run more than 20 miles?

If you’ve never run a marathon before, it might seem a little strange that training plans peak around 20 miles and never go any higher.

Many beginner runners are unsure about their ability to finish 26.2 miles, and find themselves a little nervous showing up on race day never having run further than 20 miles.

However, remember that there is a method behind these training plans.

Related: 3 Marathon Training Plans for Every Runner

Most running coaches will agree that recreational runners will do more harm than good if they run further than 20 miles during marathon training.

The reason behind this is because runs that are longer than 20 miles require runners to be on their feet for a great deal of time. These lengthy long runs usually require significantly more recovery time – time that most marathon training plans do not schedule in until after the race is over.

If you are a faster or more experienced runner, aim for your longest training run before a marathon to be about 18 – 20 miles in length.

If you are a new runner or run at a slower pace, aim for your longest marathon training run to be a distance that you can complete within 3-3.5 hours.

Understanding how far your marathon training long runs should be is key to success on race day. Here is what you need to know about long distance running to get you through any full marathon training schedule. #marathontraining #longruns #longdistancerunning

Guidelines for Your Longest Marathon Training Run

  • No less than 3 hours
  • No more than 3.5 hours
  • Cap distance at 20-22 miles
  • Complete at least 16 miles
  • Aim for a mileage range during long runs

Another thing to consider when planning your longest run during marathon training is to aim for a mileage range rather than an exact mileage before your run.

Scheduling a mileage range, such as 18-20 miles, allows for a little bit of flexibility when the long run occurs. If you find yourself feeling a little off – maybe slightly sleep deprived, experiencing digestive issues, extra stressed, or anything of the sort – you can keep the run on the shorter side.

If you find yourself feeling great during your long run, you’ll be able to run the higher end of the mileage range without guilt.

Listening to your body during marathon training is key to success on race day – and how you adjust during long runs plays a crucial role in this success.

Remember that it is always better to show up to a race slightly undertrained than it is to be even a little overtrained. Adding more miles to your long run simply because you “want to feel more prepared” is never a good strategy.

Commit to the training: fit in those weekly runs, run slow, easy long runs, emphasize recovery, and practice believing in yourself. Cut yourself some slack for any workouts that might be missed, and don’t let it derail the rest of your progress.

The long runs of marathon training are key to success on race day – but remember that there is such a thing as doing too much. Listen to your body, feel confident in your training, and aim for the longest run to last between 3-3.5 hours. With this strategy, you’ll be sure to find success on race day.

More tips for marathon training long runs:

Understanding how far your marathon training long runs should be is key to success on race day. Here is what you need to know about long distance running to get you through any full marathon training schedule. #marathontraining #longruns #longdistancerunning
Understanding how far your marathon training long runs should be is key to success on race day. Here is what you need to know about long distance running to get you through any full marathon training schedule. #marathontraining #longruns #longdistancerunning

Friday 7th of January 2022

This is a very complex issue. There are so many possibilities that I think that it is very difficult to proscribe a uniform formula. Consider this: at age 26, running about 70 miles per week, speed work included, I ran a PB of 2:36:20. Typically, I ran at least one 18 miler per week, but often, perhaps 2 on back to back days. At age 58, I averaged about 42 miles per week with a max long run of 16 miles and did a 3:20. Bottom line: the 20 miler is vastly overrated and I would submit that for most runners, it is unnecessary. If you can run 9 miles or so, you can complete a marathon. If you package your mileage smartly, you can do some amazing tings on low mileage programs with targeted speed work. Just saying.

swosei12blog

Saturday 8th of August 2020

18-20 miles for me.

Runnin' for Sweets

Saturday 8th of August 2020

That’s my preference too!

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