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How long should your longest run of marathon training be?

The distance of your long run: how far should you run?Whether you’re training for your first marathon or your 10th, the weekly long run likely comes with a lot of angst. How fast should you run your long runs? How many long runs should you do? And, finally, how long should your longest run be?

Most conventional marathon training plans call for peaking with a 20-mile long run. But some runners are finding that 20 miles doesn’t prepare them well enough for the 26.2 mile distance, while other runners are able to run successful marathons by not running any 20 milers.

Is 20 miles long enough?

Let’s get one thing straight first: if you can run a 20-mile long run, you can finish a marathon. If you’re training for your first marathon and your goal is to finish, peaking with 20 miles is definitely enough.

Experienced marathoners with strict time goals may benefit from running longer than 20 miles, though – at least according to some running coaches. Some experts say that long runs up to 22 miles are usually OK for marathon veterans. A longer long run may help a runner feel faster and stronger come race day.

However, experts caution runners to not surpass the 22-mile mark. A long run any longer is too close to the marathon distance – and the risk of injury skyrockets. A downside to long runs more than 20 miles is recovery time. The longer your long run, the more recovery time needed. It can take up to five days to recover from a run over 20 miles. That’s a lot of training time compromised, especially if you plan on running multiple 20+ milers.

But for some runners, the mental pros of running longer long runs outweigh the cons. Twenty-two miles is much closer to 26.2 miles than 20 miles is, so that extra long run may be what a runner needs to have faith in his ability to race the distance.

Or is less more?

On the flip side, not every running coach agrees with this theory. Some say the chance of injury significantly increases after 18 miles, not 22. Others say it’s not the specific distance that matters, but the time on your feet that counts.

The creators of the Hanson’s marathon training method caution against running longer than three hours, calling the 3-hour mark when runners have “crossed the point of diminishing returns”. Meaning that running for any longer would do more harm than good by damaging your muscles, compromising recovery time, and depleting glycogen stores significantly.

The Hanson method recommends peaking with a 16-mile long run while other plans say 18 miles is long enough. Still, experienced marathoners who are used to logging at least one 20-miler may hesitate to peak with a shorter long run.

Does the distance really matter?

Then there’s the third theory: the distance of your longest long run doesn’t matter – rather, it’s how you run it. Fast finish long runs will help you learn how to push the tempo on fatigued legs, and long runs with middle miles at goal marathon pace will teach you how to dial in to your goal pace on race day.

Share with us! How long is your longest run of marathon training typically?

Written by Jen Matz.

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