What Age Are Most Marathon Runners? The Real Numbers Behind Elite and Amateur Finishers

When you see a marathon finish line, you might picture a 25-year-old sprinting past in a neon singlet. But that’s not who’s actually crossing the line most often. The truth? Most marathon runners aren’t in their twenties. They’re in their thirties and forties. And that’s not a fluke-it’s backed by hard data from major races around the world.

The Peak Age for Marathoners Is 35 to 39

Analysis of over 10 million race results from global marathons between 2010 and 2025 shows that the largest group of finishers falls between 35 and 39 years old. In the Boston Marathon, for example, this age group consistently makes up nearly 18% of all finishers. In London, Berlin, and Chicago, the numbers are almost identical. It’s not even close-the next biggest group is 40-44, which is about 12%.

Why this range? It’s not about raw speed. It’s about balance. Runners in their mid-thirties have usually built up years of consistent training, recovered from early injuries, and learned how to pace themselves. They’re not chasing personal records like they did at 22. Instead, they’re focused on finishing strong, staying healthy, and enjoying the process.

Why Not Younger Runners?

You’d think teenagers and early twenties would dominate. After all, that’s when most people are at their physical peak. But here’s the catch: most people don’t start running marathons until they’re older. A 20-year-old might run 5Ks or half-marathons, but full 26.2 miles? That takes time to build up to.

Surveys from RunRepeat and the Road Runners Club of America show that 63% of first-time marathoners are over 30. Only 11% are under 25. The average age of a first-time marathoner is 38. That means most people aren’t even attempting the distance until they’re already in their late thirties.

There’s also a cultural shift. Younger runners are more likely to focus on shorter, faster races-obstacle courses, trail ultras, or track events. The marathon, with its long training grind and recovery demands, doesn’t fit the instant-gratification culture of social media. It’s a commitment that takes patience, and patience comes with age.

Women Are Changing the Game

While men still outnumber women in marathons, the gap is closing fast. In 2025, women made up 47% of all marathon finishers worldwide-the highest percentage ever recorded. And here’s the twist: women in their late thirties and early forties are now the fastest-growing group.

Why? Many women in this age group are returning to running after having kids, managing careers, or recovering from injuries. They’re not trying to win. They’re trying to prove something to themselves. The data shows their finishing times are improving faster than any other demographic. In the 2025 New York City Marathon, women aged 35-39 had the highest completion rate and the second-fastest median time of all age groups.

What About Older Runners?

Don’t think you’re too old? Think again. Runners over 50 account for nearly 20% of all marathon finishers. In fact, the number of runners aged 60 and up has grown by 32% since 2020. There are now more finishers over 60 than under 20 in major races.

Some of the most inspiring stories come from this group. Take the 2024 Boston Marathon: a 78-year-old man finished in 4 hours and 52 minutes. He’s not an outlier. He’s part of a trend. Masters runners (40+) are now the backbone of marathon events. Race organizers have even started adding special incentives-discounted entry fees, dedicated corral starts, and age-group awards-to keep them engaged.

The secret? Consistency. Older runners aren’t faster. But they’re smarter. They sleep more. They stretch. They listen to their bodies. They train with purpose, not ego.

What’s the Best Age to Run Your First Marathon?

There’s no magic number. But if you’re asking because you’re thinking about signing up, here’s what the data says: 35 is the sweet spot.

At 35, you’ve likely got:

• At least 3-5 years of regular running under your belt
• Stable work and family life that allows for long training blocks
• Enough life experience to handle the mental challenge
• A body that’s still resilient, but not reckless

That doesn’t mean you can’t do it at 28 or 52. But statistically, 35-year-olds have the highest success rate-meaning they’re most likely to finish without injury, enjoy the experience, and come back for more.

Training Age Matters More Than Calendar Age

Here’s the real takeaway: it’s not about your birth year. It’s about your running history. A 30-year-old who’s been running 30 miles a week for five years is more prepared than a 45-year-old who ran one 5K in 2020.

The best marathon runners aren’t the youngest. They’re the most consistent. They’re the ones who showed up for the long runs, even when it rained. They’re the ones who skipped the party to get eight hours of sleep. They’re the ones who listened when their body said, “Rest.”

Age is just a number. But discipline? That’s what gets you across the line.

What’s Next? Don’t Wait for the Perfect Age

If you’re wondering if you’re too old, too young, or too out of shape-you’re not alone. But the numbers don’t lie: people of all ages are crossing marathon finish lines every day. The average marathoner today isn’t a teenager with a personal best in the 2:30s. They’re a 38-year-old teacher, a 44-year-old nurse, a 56-year-old retiree. They’re ordinary people who decided to do something extraordinary.

You don’t need to be fast. You don’t need to be young. You just need to start.