Training to run 26.2 miles is a vigorous mental, physical and emotional test. Yet more people young and old are going for it.

Why it matters: Long-distance running, which experienced a pandemic-era boom, is becoming a more democratized sport. Marathon participants in their 20s are even embracing the race as a life milestone.

• "A theme that I see a lot is people are using running as a way to get through something," New York Road Runners CEO Rob Simmelkjaer tells Axios. It could be grief over a loss or the everyday stress of raising kids.
• Training for a marathon demands structure, discipline and commitment.
• "Everybody who trains for a marathon has moments of challenge, moments of pain, moments where they wonder how it's going to go," Simmelkjaer said.

The intrigue: Young people are posting about marathon training on TikTok as their "quarter-life crisis."

• The prospect of running the race "promises a profound sense of control that may be especially appealing to those coming into adulthood," The Atlantic recently reported.
• Rather than traditional markers of "adulthood" — marriage, homeownership, children — running an intense race might do.

State of play: Participation in the Boston Marathon has ticked upward across the race's more than century-long history. About 30,000 runners signed up this year for the April race, compared with only 140 men in 1924.

• Finish times have also increased, suggesting people who are older, less fit and less experienced are still securing a bib, despite the race's qualifying time requirement.

The New York City Marathon, which will take place in November, has seen turnout of 20-somethings jump in the last five years.

• The number of runners in this group increased by 21% from 2019 to 2023 — from roughly 8,230 to nearly 10,000 participants.

Between the lines: Running a marathon can offer a sense of purpose, responsibility, self-esteem and identity formation, according to Kevin Masters, a University of Colorado, Denver professor who's researched marathon participants for decades.

• It offers community, the satisfaction of reaching a goal, and lessons about your body and health. (And the chance of injury, so don't overdo it.)
• While running, people also think — and it can lead them to solve tricky work problems, or remember people they miss and decide to reach out, Masters said.

It can force participants to reorganize their lives.

• "Even eating becomes interesting because you can't really slam down a big burger and then go out and run 10 miles," Masters said.

NYRR lists more than 250 running clubs on its website for a range of identity groups, including Black, Latino, Asian, LGBTQ+ and faith communities.

• Those groups might fill holes reflected in young people's shift away from more organized groups, including religion.

Reality check: Running is free and doesn't require a gym membership, but training for a long race poses some economic barriers.

• Training requires time, access to trainers and good shoes, and park or track options for long runs, Simmelkjaer said.

My thought bubble: I'm 30 and running my first marathon in Philadelphia this fall. I'd initially planned to run the New York Marathon in 2021 through NYRR's 9+1 program in 2020, but I'm bored with that foiled story.

• I've been inspired reading Haruki Murakami's "What I Talk About When I Talk About Running" and adapting to a lifestyle with no alcohol and restorative rest.
• Building out a training plan, which often varies from 16 to 20 weeks, is also a fun way to map out the rest of the year and connect with marathon runners in my life.
• Scheduled runs marked "AYF" suggest going as you feel — whatever pace works.

The bottom line: Making it to the marathon starting line is an accomplishment, the culmination of much perseverance and resilience.

• "I want to say to all of you, congratulations," Simmelkjaer told runners at the starting line in Staten Island at the 2023 New York City Marathon.
• "The actual day of the race is more of a celebration than it is the hard part."

Editor's note: This story has been updated to note New York Road Runners lists local running clubs it engages with on its website.