#AskCoachCourtney: Do I have to run a 20 miler when I train for a marathon?

Welcome to #AskCoachCourtney! Each week or two, I take questions from my loyal readers and followers. I had a few submissions this week, and this one stood out to me because it’s often debated: Is a 20 mile run a standard necessity during marathon training?

The short answer: No.

There are a lot of coaches who would disagree with me (Hal Higdon included), but based on what we know about the science of running and high impact exercise, whether you run 20 miles during marathon training or not is individual and varies depending on your easy run pace, goals, and more.

We see the challenge surrounding it. Some of us may forgo training for a marathon because of it. We invest so much thought and worry in it. We dread the day that it comes.

Nope — I’m not talking about repairing your torn meniscus; I’m talking about the almighty 20 mile training run that seems standard in most marathon training plans! Find any generic marathon training plan on the internet right now, and I can promise you that there’s a 99.9% chance of a 20 miler somewhere in the mix.

I have great news for you, though: You may not need to run 20 miles as part of your marathon training. It’s often a heated debate among seasoned marathoners and running coaches, but I stand firmly that time on your feet is what you should measure when it comes to long runs during marathon training.

Sports science says that more than about three hours of consecutive running doesn’t provide health and training benefits. In fact, spending more than three hours running may actually increase your chances of injury and lower your ability to recover in an optimal amount of time. Runners World agrees, according to an article published in February of 2019: “While it is important to have banked some good time on feet in your longest long runs, if you go too long you’ll struggle to recover and start your marathon already tired. Nothing magical happens at 20 miles in a training run.”

Your long runs should be paced at your easy run pace (to read more about how to develop and maintain an easy run pace, click here). If you run at said pace for three hours, you may or may not reach the infamous mile 20. My easy run pace is around 13:30, so it would take me waaaay longer than three hours to get to 20 miles. During my first 26.2, I didn’t run more than 16 miles during training for that very reason: It likely would have wrecked my physical health in more ways than one. This year, I may not make it past 14, but that’s fine — it’s the time on your feet that matters more than a mileage number.

The goal, when training for any distance, is to step up to the start line strong, recovered, and ready to race. “Racing” means something different to all of us, but I’m using the term pretty generally here: Whether your goal is to finish a race or qualify for Boston, you want to take off feeling rested and able, not tired and burnt out.

In other words, every runner is individual. A 20 mile training run takes less than two hours for some and almost five hours for others. All runners should avoid over-training, and long runs should be tailored accordingly. As you approach your next training cycle, keep this in mind so that you don’t end up exhausted and injured!


Do you have a question for Run Coach Courtney? Fill out the contact form, leave it in the comments, or send a DM on Instagram.

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