I feel like I’ve been asked this question about a bazillion times since I started this marathon training thing. I may have even wondered it myself prior to buckling down and doing the training.
But the training involves me running about 4 times a week, one long run, and then 3 others. The long runs never go over 20 miles, and I just did my 20-miler last week. And folks seem beyond puzzled. So we chatted about it at work. I did my research. And I bring to you the answer.
I don’t really know. That’s just what the training told me to do so I did it.

Sike. So you can search high and low for marathon training programs. Generally, most will be something like mine. Some of the more advanced programs, for folks who may be more experienced and more elite may call for you to do maybe two 20-milers in the course of training. But I’d be surprised if you could find a legitimate training program that would tell you to run over 22 miles. Here’s why. For one, there’s no training for 26.2 miles quite like a marathon. Second, and this is coming from pretty seasoned pros, 20 miles is all well and good. Much more than that for a simple training run, and you are shredding your body and legs. And your body will need a long long time to recover from that. So the deal is, if you’re training along with me for a marathon, follow your training program. And though it may feel counter intuitive once you begin to taper (OMG, my mileage is decreasing?!), there’s a method to the madness. On race day, you’re supposed to be rested, refreshed, and raring to go. And the only way you do that is to get your super long runs out of the way about a month out, and then starting to let your body rest, heal, and hydrate for the big day. How do you prepare for childbirth? How do you prepare for your wedding day? You get ready. Read the books, do your training, and you talk to people who’ve done it. Now I hope you guys can deal with the crazy as taper madness begins to descend on my household!
I’m midway through training for my first marathon and think about this often. Before I started my program, I couldn’t understand how I could push myself to 26.2 if I’d only run 20. Now it all makes sense to me! All the training miles plus the rest and taper will get us there…and six more miles seems much less intimidating given all the miles we will have run…not easy, but not impossible. Good luck with your taper madness!
You too! Hope that explanation makes sense!