For some, a midlife crisis arises from a fear that the weaknesses that have dogged you are not just temporary challenges to cope with, but a permanent part of who you are. The chance to confront those weaknesses and recognize the hold they have over us is a key benefit of ultra-marathons, Cross-Fit, or whatever other endurance sports people turn to.

Christine Cassara was one of these people. She and her husband were struggling with fertility issues, and at one appointment the doctor told her he’d rather treat a 40-year-old than someone who was obese. The cruelty of the comment took her aback. Cassara was pushing 40 and weighed 340 pounds.

After a couple of false starts, Cassara lost over 200 pounds with the help of a diet, but she worried about backsliding, so she tried running. Beginning with a couch-to-5K plan, she worked her way up to half marathons and signed up for a full marathon only to realize she didn’t actually like running all that much. A friend suggested triathlon, and she started small with pool laps, short bike rides, and mile runs. Cassara fell in love with the sport and completed Sprint and Olympic triathlons. In late August she traveled from her home in St. Petersburg, Florida, to Copenhagen for her first Iron Man.

“In the back of my mind I always considered myself a quitter,” Cassara says. “The most important thing it’s done in all aspects is to give me the will to continue and not quit.”

Others experience a midlife crisis as a sense of slackening, of lost focus, or ambition. That’s what Lisimba Patilla, a 44-year-old sales manager from Medina, Ohio, by way of Flint, Michigan, felt when he discovered triathlons. Three years ago, the former Division-II college football player and track athlete worried he had grown complacent in life and was losing his edge.

On a business trip to Reno, a cousin recommended a book on triathlons, and Patilla was so inspired he called his wife and told her he was going to be a triathlete. There was one significant problem. He nearly drowned when was 12 and the experience left him so traumatized he wouldn’t let water from the shower hit his face.

“If you fall off your bike and get a wound on your leg, you can still get on that bike,” Patilla says. “When you have a traumatic experience, it puts a wound on your mind, and it becomes a recurring nightmare.”

Patilla bought the thickest wetsuit he could find and experimented with a half-dozen snorkels. In his first triathlon attempt, he made it 500 meters before being pulled out of the water. From that point on he told himself that he was going to swim like everyone else. Patilla went to a pool twice a day and learned how to swim in the shallow end. He competed again a few months later and completed his first sprint triathlon.

Extreme fitness is less about being young again and more about building yourself up for the years ahead.

“I can’t tell you I didn’t panic,” he says. “I can’t tell you a grown man didn’t cry. But I got through it. When I got done, I was exhausted, but I knew at that point I could do this.” He did, and in doing it, he gained a measure of clarity about what he’s capable of. “Triathlons don’t lie,” he says. “At 44 years old I need that.”

When Suzanna Smith-Horn burned out on the corporate lifestyle in her 40s, she sold her shares in her startup and quit her job. Her friends thought it sounded fantastic to have all that free time, but Smith-Horn struggled with the loss of identity. “The reality was that’s a really tough place to be,” she says. “Because you’re trying to figure out, what should I be doing in life? Who am I? What’s my purpose? I went into these places in life where I was pretty depressed.”

She started running, and her existential question was answered. She ran a marathon and then advanced from there to 100-mile races. With a career in tech sales, Smith-Horn, now 51, is able to work from her home in the Upper Valley of Vermont where she has access to a wide assortment of trail systems. There are days when it’s hard to get out the door, especially in the bitter cold of winter, she says, but after a few miles, her mind clears.

“Sometimes you’ll be like, where am I?” Smith-Horn says. “You’re in the zone. Nothing else really matters and you’re just there. It doesn’t come overnight. You learn every race, every trail. You’re constantly learning. You have to learn how do you take care of yourself. You really have to learn how to manage yourself for hours on end without a lot of support.”

This realization was hard-earned. During the winter of 2016, Smith-Horn slipped on a patch of ice and broke her neck. Her doctor told her that running was off limits and so was hiking, but she had the Grindstone 100, an ultramarathon, on her schedule that fall and that was non-negotiable. She walked every day for 4–5 hours with her neck brace to maintain her fitness.

Eight months after her fall, the 51-year-old finished the 100-mile race in the Allegheny Mountains, in just over 31 hours, beating half the field of finishers and coming in 10th among all female runners. Not that place has much relevance to her.

“I’m a 50-year-old middle of the pack,” she says before catching herself. “Ehhhh, I hold my own. Everyone has a story and there’s an importance to everyone who’s out there, whether they’re finishing a course in record time or the last one finishing. We’re all doing the same thing.”