You Can Run 100 Miles on Marathon Training

“If you can train well for a marathon, I think you can do 100 miles,” says Eric Orton, an endurance coach best known for whipping journalist Chris McDougall into ultra shape in the book Born to Run. 

For busy people with ultra dreams, perhaps no sweeter words have been spoken. Even better: he’s not the only one speaking them. “You can be perfectly successful if your min/max—that’s the minimum training volume you need when your volume is at it’s max—is nine hours per week for six weeks,” ultra coach Jason Koop, director of coaching for Carmichael Training Systems, agrees. 

At the core of both statements is the classic quality over quantity credo. “Often people run a little bit more and they do well, so they think more is better,” Orton says. “I think better is better.”

Better means building strength and speed over volume. For Orton, that means running hills, doing sprint intervals on hills, and learning to love the mile. “To do better, you have to get faster,” he says. “And the greatest predictor is one mile. You have to get faster at one mile to get better across the board.”

It also means substituting mountain hiking for long easy runs. “People get into trouble when they start logging all of these mountain miles and running them because they can. But they’re running themselves into the ground because it’s way too hard on a consistent basis,” Orton says. “It’s the equivalent of running marathon pace every day.” 

Which is why Orton believes the solution lies in strength. “Strength builds endurance, not the other way around,” he says. In the early season, Orton has his athletes climb as easy as possible to build up and downhill leg strength while staying aerobic, or around 75 percent of max heart rate. The point of this is to build efficiency at staying aerobic so that runners don’t need as much recovery on the downhills—the part of a race where ultrarunners can make up a lot more time than if they’d tried to run fast uphill. 

Just like with marathoners, Orton also has his athletes do threshold runs, or runs performed at 85 to 90 percent of their max heart rate. “Instead of going off on an eight-hour easy run, do a three-hour hard run with a lot of hills and threshold type of climbing,” Orton says. A tough run at the peak of training could look like this: easy warm-up, 20 minutes at threshold, two hours easy to moderate, 20 minutes at threshold, then cool down. 

Koop similarly incorporates intensity into his ultra athletes’ workouts, focusing on one element at a time, whether that be lactate threshold (workout example: 4×10 minutes hard, 5 minutes easy), VO2 max (6×3 minutes hard, 3 minutes easy), or high-end aerobic work (40 to 60 minutes at marathon pace). But you must do these workouts on terrain similar to that of your race—skip the track. “Do whatever you can to match your training vertical to the race vertical,” Koop says. Say you know you’ll gain about 150 feet per mile during the race; try to get that in during training to prime your muscles and mechanics for what’s coming. Similarly, he says, if you know you’ll be hiking 10 percent of your race, 10 percent of you training should be hiking.

With that strength base, athletes “can go from a two-to-three hour run to run eight hours no problem,” Orton says.  That’s exactly how he trained Born to Run author McDougall for the 50-mile Copper Canyon Ultra, now known as the Ultra Caballo Blanco. “He just needed strength,” Orton says. 

“It was such a transformative experience,” McDougall says of following Orton’s plan. “I kept waiting to feel bad but month after month I just kept feeling good—you’re on an upward slope all the time.” 

All of that said, a high-quality, lower-mileage approach doesn’t nix some epic workouts. If you’re gunning for 100, Orton recommends doing one longer run once a month. “Everyone can fit that into their schedule,” he says. You should complete five to six long runs before race day, with the final long run performed four weeks before the event and lasting about six to seven hours. 

Those longer efforts will get your mind, body used to being out in the wilderness, and your stomach used to fueling. “Experiment with different foods during your longer runs,” Koop says. “It teaches you what’s not going to work so you’re left with a basket of things that could work in the 20 hours of unknown.” He recommends testing several snacks that cover the sweet, salty, and savory categories. That way if your favorite training foods stop working for you at hour 17 in the race—something you could never have predicted with your longest run topping out at less than half that time—“you’ll have a list of other things you can incorporate into the mix.” 

For these long training runs, you’ll have to throw the 10 percent rule out the window and focus on time spent on your feet. Don’t worry about the mileage, Orton says, “especially if you live in a trail environment because three hours could be six miles.” Perhaps your first long run is two hours. Four weeks later, your next will be three hours, and so forth until you hit six or seven. “If you’re just looking to finish your first 100 miler, you just need to be able to locomote without having a whole lot of stress on the system,” Koop says.

Once you’ve done that final long run and taken a rest week, it’s time to taper. That means keeping up your running frequency and intensity while reducing your weekly training volume. Maintaining intensity is key, Orton says. “That’s what keeps you fresh. The reduction in volume, that gets you rest.”