On a warm, rainy, summer day, I crunched up a gravel path at the Moses H. Cone Memorial Park in Blowing Rock, N.C. It was my third day of running uphill — in the rain.

On the way up, I tried to chat with Chrissy Stuckey, a 36-year-old dancer from Toronto, but I was running out of breath. She was training for a marathon, and I was not. I prayed we’d soon reach the top of the hill so I would stop huffing, embarrassing myself in front of the 30 or so other runners out on the trail that day.

I’m not on a high school track team, or a college runner. I’m not even that fast a runner for someone my age. I’m 36, and last August I went to camp. To run.

Running camps for grown-ups aren’t exactly new, but they have become more popular, according to Randy Accetta, director of coaching education at the Road Runners Club of America and the mentor in residence at the University of Arizona’s McGuire Entrepreneurship Program.

“We’re seeing a national push toward experiential consumption,” said Mr. Accetta, who also directed running camps at the Craftsbury Outdoor Center in Craftsbury Common, Vt., from 1996 to 2008.

Since the end of the last recession, he’s seen a growing number of people — especially women, who have driven the explosive growth in running since 2008 — willing to put more money into what they love by signing up for running camps. “They want to do their passion, and they want to master it, and they want to do it in a cool setting with cool people,” he said.

The Craftsbury Outdoor Center started its adult running camps in the mid-1970s, and the current running camp director, Carole Hakstian, said they can’t keep up with demand. They now offer nine camps with 20 to 25 runners a session and she says there could be more if the camps didn’t share the outdoor center with sculling and cycling retreats.

Craftsbury offers four-day and seven-day sessions, which cost $694 and $1,135, including room and board. Participants run twice a day and have classroom sessions on injury prevention, nutrition and exercise psychology, along with yoga sessions. Ms. Hakstian said that campers range from those training for 5Ks and 10Ks to ultramarathoners. The youngest camper last summer was 23; the oldest was 84.

“At every one of these camps, the majority of people say that they’re at camp because they’re looking for something to motivate them,” Ms. Hakstian said.

Rob Krar, a professional ultrarunner, and his wife, Christina Krar put on the first Rob Krar Ultrarunning Retreat in Flagstaff, Ariz., in 2015, drawing 14 runners. This year they’ve held two already with two more on the schedule, with up to 20 spots. They get everyone from beginner ultrarunners — this is a world in which a beginner is someone who’s just run a 50K — to experienced 100-mile race runners. Ms. Krar said that at a minimum, they expect runners to be able to run nine to 15 miles a day.

Retreats are five or seven days and cost $1,550 to $2,150, including food and lodging at a hotel. Runners work out in the morning, followed by a picnic lunch and education sessions in the afternoon. Most runs are done in and around Flagstaff, but each camp also does one workout in Sedona, and weeklong camps include a run at the Grand Canyon, providing sightseeing opportunities.

“To me, I am fostering an environment where people can forge connections with each other and learn more about running but also about themselves,” said Ms. Krar, who has a background in experiential education.

The camp I was attending, ZAP Fitness, held its first camp at a facility built for that purpose in Lenoir, N.C., in 2002, and it now holds five all-comer camps a year; it also hosts high school and college camps and rents out the facility for others to host. Four-day camps cost $750, and six-day camps cost $1,050.

Zika Rea, a former professional runner and second-place finisher in the 2005 United States Marathon Championships, co-founded the ZAP Fitness Foundation in 2001 with her husband, Andy Palmer (ZAP stands for Zika Andy Palmer). The two met at a camp Mr. Palmer had put on in Maine.

“He was trying to find a way to run adult running camps and work with recreational runners and runners at all levels and give back to the sport of distance running and help with the development of American runners,” Ms. Rea said.

After Mr. Palmer died in 2002, Ms. Rea continued the running camps, which fund, in part, the ZAP Fitness Team, a professional distance running group (additional funding comes from private donations and Reebok).

I met a lot of return campers that week, like Ms. Stuckey, the dancer who kept me going on that hill. The 2016 camp was her third. “It gets me looking at training in a different way,” she said. “I think it’s cool to work with coaches at this level and really nice to be able to observe the athletes because I want to keep getting better.”

Most camp attendees that week had heard about ZAP Fitness through their local running clubs or from friends who convinced them to go. Carrie Williams, a 44-year-old marketer from Atlanta, heard about ZAP from a co-worker who “told me how amazing his experience was last year and got me so excited that I had to go,” she said. “It’s really hard as an adult to meet new people who have the same kinds of passions you have.”

ZAP’s camp didn’t physically resemble the Girl Scout camps of my youth — we slept in a place that had walls and showers and flushing toilets, after all — but the sense of camaraderie was similar. I went into camp without a fall marathon on my schedule and soon after signed up for two. Within the setting of 30 other runners who took a week of their regular lives to go running, this seemed perfectly normal.

For the first time, Mr. Accetta of the Road Runners Club will be a camper, rather than a coach, when he and his wife attend a Wilder Retreat, a four-day camp that focuses on running and writing in Bend, Ore., in August. His wife paid for the retreat as a gift. He’s looking forward to seeing things from a different point of view, and loves the idea of getting away and “being able to focus and channel three of my passions: running, writing and my wife.”