How Long Should Your Long Runs Be When Training for a Race?

I’d been her go-to person for running advice and positive reinforcement during her training block. She didn’t really need me— she was crushing her long runs and felt good about the progress she had made, so her frantic call was unexpected. I asked what was wrong.

“Well, I felt like I needed to do the full 13.1 miles,” she said. “So I did. Now my butt hurts.”

How long should long runs actually be when training for a race? Well, we’d talked about how most training plans didn’t go up to the full race distance and that it was by design. There was no need to go over 10 miles to have the fitness necessary to complete the half marathon.

So why did my friend go totally against her plan and all practical advice? Her reason: “Just to make sure I could.”

Christine Conti, a running coach and fitness specialist, is familiar with the need to instill confidence in runners throughout the training process and recognizes the fear first-time racers face.

“They’re doing their training and they really believe that if they don’t try it first, they’ll never make it,” she says. “And we’re told in life, ‘practice, practice, practice.’ You don’t want the first time you do something to be the big show, right? But you really shouldn’t do it.”

When I think back to my first half marathon, I remember the doubt and fear. How can you know you can reach the finish line if your longest long run is only 10 miles?

Well, good news: There’s proof you can finish a race without running the full distance first, so you don’t have to try it—and you can avoid a literal pain in the butt.

Why don’t training plans go the full race distance?

Contrary to popular belief, most training plans are designed to go just short of the full mileage of the race you’re running, according to Katherine Campbell, CPT, DPT, a physical therapist, personal trainer, and running coach.

“Typically most general half marathon plans only go to 10 to 11 miles because they’re made for beginners,” Campbell says. “As a beginner or even intermediate runner, you want to make sure you’re recovering enough from your long runs where you can get the aerobic benefits without actually putting too much load through your musculoskeletal system to cause injury.”

This is the same reason your marathon training plan usually only goes up to a 20-mile long run—not the full 26.2 miles.

A more advanced half marathon training plan can go above 13 miles—sometimes up to 16 miles. But the thing is, many runners using this type of plan are faster than beginners who are sometimes running a double-digit-mile long run for the first time and should be conservative with their pace.

“Running faster paces would equal out to the same time on feet as most beginners running 10 to 11 miles,” Campbell says.

That’s the key: time on your feet. Especially when it comes to marathon training where slower runners could potentially be slogging through long runs for hours.

“Anything after a three-hour long run doesn’t have a drastic aerobic benefit, but it does drastically increase your risk of injury,” Campbell says. “As a physical therapist and coach, I will usually cut runners off at about 3.5 hours as a peak long run. A typical ‘average’ pace is usually around a 10-minute mile, and 3.5 hours at that pace is usually 20 miles.”

Half marathoners could go up to 13 miles in under three hours, but every mile out there while you’re tired is a chance for your form to break down. Unless you have excelled in your base training and have already tackled seven miles for your long run, it’s not worth going above 10 or 11 miles for your longest long run.

What’s the risk of running the full distance before the race?

The more you’re running on tired legs after a log training block, you might subject yourself to overtraining.

“Running a full distance before the race dramatically increases your risk for injury,” Campbell says.

In addition to sore and tired muscles, there are other systems in your body that go a little haywire following 26.2 miles. Your cardiovascular system is amped, your kidneys are working overtime to filter waste from your blood during and after your marathon, and your immune system weakens in the hours following such a long distance.

“There’s so much happening on a physiological and musculoskeletal level that if you ran more than 26 miles before the race, you’re risking not giving yourself enough time to recover to actually perform on race day,” she says.

You must tell your brain to stop doubting the structure of the plan, according to Conti.

“Beginners might look at these training plans without understanding the science behind it,” she says.

A well-made plan—meaning one made for you by a coach or designed by an expert—will bring you up to your physiological edge to help prepare your body for the aerobic challenge of a long distance and then back off just before race day.

“A nice taper two to three weeks before the race will make your legs fresh. Trust that the training, optimal recovery, and fresh legs will get you there.” —Katherine Campbell, CPT, DPT

What is ‘tapering’—and how will this strategy help you run your full race distance?

The point is you don’t want to be out on the road for too long lest you get hurt or sick. You might be wondering why you don’t hurt yourself during the actual race. It’s thanks to the magic of the taper.

During the taper phase in half marathon and marathon training, your body recovers from the high demand of the training weeks before. By reducing training volume and intensity in the weeks leading up to the race, tapering alleviates accumulated fatigue, repairs muscle damage, and replenishes energy stores. Because you’re racing on healed legs, you’re less likely to face injury.

“A nice taper two to three weeks before the race will make your legs fresh,” Campbell says. “Trust that the training, optimal recovery, and fresh legs will get you there.”

How to embrace the unknown of the last few miles

So you don’t want to get hurt. You don’t want to get sick. You’ve decided to follow your plan and have vowed not to go the full distance. But you’re still nervous. Mentally, how should you deal in the weeks leading up to the race?

It’s about trusting yourself and the training you’ve already done. As many old-school coaches will say, “The hay is in the barn.”

“I remind my clients that you should be looking at the amount of miles you run per week,” Campbell says. “You’ve trained your body to run the distance if you have been averaging over 26 miles per week for a marathon and 12 miles per week for a half marathon.”

If you can convince yourself that you’re physically prepared, you’re mind should settle down.

“For me, my first marathon was a bucket list item. I thought the people who ran these races were superhuman. I had no idea your body could actually run or perform for that amount of time without dying. But I trusted that if I followed the plan, I would do it.”

For her first half marathon, Conti never ran more than a nine-mile long run.

How to mentally preparing for the final stretch of your race

There are some tricks to help the last miles fly by. First, ask other runners about their experiences in the last couple miles of a race. For me, the last two miles of my first half marathon were exhilarating. I celebrated each step I took after the 11-mile mark because every step represented the farthest distance I had run in my life.

My first marathon was a little different. The last three miles were a total pain cave, but there was no freaking way I was going to give up. You’ll feel the same way.

Aside from sheer determination, here are other tactics to pull you to the finish:

1. Use the crowd

At big races, crowds will line the street leading up to the finish. Their cheering will create an electric atmosphere.

“A fun tip I like to give my runners is to have your friends and family scattered throughout the last few miles to give you that extra energy boost, too,” Campbell says.

2. Break up the distance

You might be doing this throughout the race, but it’s especially useful in the last few miles.

“It’s all mental,” Conti says. “Think about it like, ‘Oh my gosh, all I have is a 5K left. I’ve done this a million times.’ Or ‘I have six miles. That’s two 5Ks. That’s easy.” You’re almost done. And if you have to give yourself some grace and walk a little bit, you’re still going to make it. You’re going to be fine.”

3. Repeat a mantra

Both Conti and Campbell say mantras are a proven way to keep your mind right as you go into the last miles of a race.

“I am all about mantras,” Campbell says. “Find one, practice it, and keep saying it.”

Campbell also suggests writing down one win each week throughout your entire training cycle.

“Read all of them and come up with three positive reasons before your race that remind you that you’re prepared for the race,” she says.

Conti has another perspective that can make the last bit of your race go faster. Think of your half marathon as only 12 miles or your marathon as only 25 miles.

“Because the last mile you run with your heart,” she says.