2025 Boston Marathon Men’s Preview: Can Conner Mantz Make the Leap Into Contention?

Just when you think you have the Boston Marathon figured out, it throws in a surprise.

In 2014, we at LetsRun.com meticulously ran through the numbers to calculate the odds of an American winner. We landed at somewhere between 1 in 27 and 1 in 19,813. So of course that was the year Meb Keflezighi ended a 30-year American drought in Boston.

Last year, Sisay Lemma of Ethiopia entered the race having run it three times before in his career with each race being a total disaster: DNF (2017), 30th (2019), DNF (2022). So did he take things conservatively and try get his Boston legs under him? No.

Buoyed by his 2:01:48 win in Valencia in his previous marathon, on Marathon Monday he went through halfway in a suicidal 60:19 — you’re never meant to go out that fast on a course that features the most famous hills in running during its second half. Somehow, Lemma held on and won.

This is why we love the Boston Marathon. The lack of pacers, the historic point-to-point course, the uphills and downhills, and the unpredictable weather means that it defies easy description. Whether you are racing on Monday or watching from the sidelines or on TV, all you can do is prepare yourself for what is about to come and enjoy the ride.

Fortunately, getting ready to watch Boston is a lot easier than getting ready to run it. No hill reps or long runs required. Just read this preview, and you’ll be prepared (or as prepared as you can be) for the men’s elite race. (Women’s preview coming soon).

The big story in 2025 from an American perspective is Conner Mantz, America’s top finisher at the Paris Olympics (8th) who in January ran 59:17 at the Houston Half Marathon to break Ryan Hall‘s longstanding American record. Mantz has clearly established himself as America’s best marathoner, but he measures himself against the best in the world. And in that respect, Mantz is still searching for his first podium finish in a World Marathon Major — he’s never finished higher than 6th. Monday is his best chance yet to do it.

Standing in his way are the likes of defending champ Lemma, 2024 Chicago Marathon champion John Korir, two-time Boston winner Evans Chebet, Kenyan Olympic trials 10,000m champion Daniel Mateiko, and 2023 world champion Victor Kiplangat.

Below, we break down Mantz’s season so far and the reasons why he could (and could not) contend on Monday, before previewing the rest of the elite field and analyzing the other top Americans, led by Olympic 9th placer Clayton Young and 2:08 man CJ Albertson.

We also talked about this on this week’s LetsRun.com Track Coach Podcast with Ben Rosario, founder of HOKA NAZ Elite, the Marathon Project, and now the Flagstaff Coaching Clinic with Mike Smith and Greg McMillan (which he is advertising on LetsRun.com).

Clip on Conner’s chances below.

Full podcast here.

Race details
What: 2025 Boston Marathon
When: Monday, April 21, 2025. The professional race begins at 9:37 a.m. ET.
Where: Hopkinton to Boston, Massachusetts (course map)

*Full entries *How to watch

Race-day weather forecast: The current forecast for Monday calls for temps in the upper 40s with a slight headwind out of the east (4-8 mph).

Can Conner Mantz make the leap?

There has not been this amount of excitement around an American man running Boston since 2018, when Galen Rupp entered the race fresh off a victory at the Chicago Marathon. So of course that was the year a biblical flood rained down on race day producing arguably the unlikeliest Boston winner ever in Yuki Kawauchi. Anything can happen in this race.

In Houston, Mantz took down an American record in the half that had stood for 18 years (Kevin Morris photo)

Mantz is not at Rupp’s level yet, but he has inherited his title as America’s #1 marathoner. And he has started 2025 on a hot streak. After setting that 59:17 AR in Houston on January 19, he ran even faster (59:15) at the NYC Half on March 16. That 59:15 was not eligible for the American record given NYC is a point-to-point course, but NYC is also regarded as a tougher course because of its hills. It’s safe to say this is the fittest Mantz has ever been.

“His build has been as good or better than any other build we’ve ever had,” Mantz’s coach Ed Eyestone told LetsRun. “It’s been kind of a public build because he’s had some races that he’s performed very, very well at.”

Part of the reason for that is that Mantz has been able to stay healthy for the last three months since Houston. Mantz pushes harder than just about any American in training, which often leaves him riding a fine line between supreme fitness and injury. Before last year’s Olympic Trials, he developed a stress reaction in his femur. Before the Olympics, it was a torn quad. Before Houston this year, a quad strain. Each time, Mantz was able to preserve that fitness by cross-training like a maniac, and he ran well in all three races. But it’s better to avoid an injury altogether, and while Eyestone said Mantz has had a few minor issues in this build, they pale in comparison to the ones he faced in 2024.

All of this means that we should see the best version yet of Mantz in Boston, which makes it a critical race in his career. Because on Monday, we are going to find out how good Conner Mantz really is.

Consider: Mantz is squarely in his prime at 28 years old. Boston will be his seventh marathon. He has had the best training of his life. If he cannot at least contend for the win on Monday, you have to wonder if he ever will.

The case for and against Conner Mantz

In the last 41 years, only one American has won in Boston (Meb Keflezighi in 2014). Which means that whenever an American gets remotely close to contending, the media starts salivating (guilty). But how serious is Mantz as a contender, really? You can spin an argument either way, so that’s what we’ll do. Here are the key talking points around Mantz and how each simultaneously helps — and hurts — his case for contending in Boston.

“He had a really good season in 2024”

Mantz was the top American at the Trials, Olympics, and NYC in 2024 (Kevin Morris photo)

The case for Mantz: Mantz ran three good marathons last year. He won the Olympic Trials, was 8th at the Olympics, and finished 6th in New York in 2:09:00, the fastest ever by an American man on that course.

The case against Mantz: Good marathons are nice, but great marathons win majors, and Mantz is still looking for his first great marathon. Dathan Ritzenhein (9th in 2008) and Jared Ward (6th in 2016) both finished in the top 10 at the Olympics, and neither came close to winning a major. Mantz may have run 2:09:00 in New York, but 6th is a long way from first, and he couldn’t hang when Evans Chebet made his big move at 16 miles.

And consider that while Mantz always beats his training partner Clayton Young (he’s 5-0 vs. Young in their marathon careers), the gap between them has not been that wide. Young basically let Mantz win the Olympic Trials, and in their last four marathons, Mantz has finished exactly one place ahead of Young each time, with an average gap of 16 seconds. Yet no one is talking about Young winning a major anytime soon.

“He’s been crushing it in the half marathon in 2025”

The case for Mantz: Running 59:17 and 59:15 clearly shows Mantz is in shape heading into Boston. And if anything, those times undersell the performances. Houston featured cold and windy conditions, and NYC is a hilly course — NYC winner Abel Kipchumba, who finished just six seconds ahead of Mantz, is a 58:01 guy.

The case against Mantz: Running in the 59:10s twice is a good sign, but it’s not any better than what the other contenders in Boston are capable of. John Korir ran 58:50 at RAK last year. Daniel Mateiko ran 58:17 in Valencia in October. And Kipchumba, who beat Mantz in NYC, is also running Boston. In a world where the world record is 56:42, we may not want to get too excited about a 59:15, even if the course is a little slow.

“He is capable of running much faster than 2:07”

The case for Mantz: Mantz’s personal best is “only” 2:07:47, which he ran at the 2023 Chicago Marathon. But that is misleading. That was also the last time he ran a rabbitted marathon, and all three of his marathons in 2024 were superior performances. Mantz ran 2:08:12 on a brutally hilly Paris course that probably ran around three minutes slower than a flat marathon.

Eyestone essentially views Mantz as a 2:04 or 2:05 guy, and he’s not wrong to do so.

“If Conner Mantz were running Valencia in a year where there’s a ton of guys running 2:04 or 2:05, I think he’s going to be competitive in that,” Eyestone said.

The case against Mantz: In 2025, 2:04 ability is the minimum requirement to have a shot at winning a major. The top three guys in the 2025 Boston field, all of whom have won majors in the past two years, are Sisay Lemma (2:01:48 pb), John Korir (2:02:44 pb), and Evans Chebet (2:03:00 pb). Of the seven winners of last year’s World Marathon Majors (including the Olympics), six either had a pb under 2:04 or ran under 2:04 to win the race. The lone exception was NYC champ Abdi Nageeye (2:04:45 pb) — though he also had an Olympic silver medal from 2021.

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Sizing up the rest of the Boston field

So where does all of this leave Mantz?

Well if he’s serious about winning a major one day, he’s in the right race. Boston has no rabbits, which makes it less predictable and gives him more routes to victory. Whereas in a rabbitted race like London/Berlin/Chicago, you basically have to be able to run 2:01 or 2:02 — something Mantz is unlikely to do. Showing up to Boston and New York, year after year, is his best shot at the podium and a win, just as it was for Meb, Shalane Flanagan, and Des Linden.

But it’s still a monumental task. Here’s how I would categorize this year’s contenders in Boston:

Level 1: Proven marathon stars

Sisay Lemma (2:01:48 pb), John Korir (2:02:44 pb), Evans Chebet (2:03:00 pb)

These guys are the safest bets in the field. Lemma has wins in London (2021), Valencia (2023), and Boston (2024), and if he didn’t get injured last summer, he would have been the favorite for the Olympic gold medal in Paris that ultimately went to his replacement on the Ethiopian team, Tamirat Tola. Lemma was only 10th in Valencia in his last marathon, but he was still on the comeback trail from injury for that one. He should be better in Boston.

Chebet, the Boston champ in 2022 and 2023, has also dealt with injuries in the last few years, but showed in 2024 that he is still very competitive, finishing 3rd in Boston and 2nd in New York. Expect him to make a big move somewhere in Brookline once the pack is through the Newton Hills.

The concern about Lemma and Chebet is that eventually, the wheels are going to fall off. Lemma is 34 and Boston will be his 28th career marathon. Chebet is 36 and has been racing marathons since 2013. At some point, these guys are going to show their age.

But Korir, younger brother of 2012 Boston champ Wesley, may just be entering his prime. He is 28 and went from 9th in Boston in 2023 to 4th last year to 1st in Chicago in a pb of 2:02:44 in October.

Level 2: High-upside guys

Cybrian Kotut (2:03:22 pb), Haymanot Alew (2:03:31 pb), Daniel Mateiko (2:04:24 pb), Victor Kiplangat (2:05:09 pb)

These guys don’t have quite the track record of the first group, but they’ve shown enough to suggest they could win a major one day. Kotut, who trains alongside Kenyan stars Evans Chebet, Benson Kipruto, and Sabastian Sawe, has recent wins in Hamburg (2022) and Amsterdam (2023) and is coming off a 2:03:22 pb for 2nd in Berlin. He was only 9th in Boston last year, but he has the talent to win.

The 26-year-old Mateiko, who is coached by Eliud Kipchoge‘s coach Patrick Sang, is coming off a career year, with wins in the RAK Half and the Kenyan Olympic 10,000 trials and personal bests in the 10,000 (26:50) and half marathon (58:17). Most importantly, he finally ran a good marathon after DNFing his first two attempts, finishing 3rd in Valencia in 2:04:24.

The Ugandan Kiplangat, the half-brother of half marathon WR holder Jacob Kiplimo, was only 15th in Tokyo last year and 37th at the Olympics. But he has won some big championship marathons (2022 Commonwealth Games, 2023 Worlds) and was the 2017 World Mountain Running champion, which makes him a nice fit for Boston’s course.

Alew was 3rd in Berlin last year, only nine seconds behind Kotut, and also finished 2nd in Hamburg.

(For more on Kiplangat and Kiplimo’s back story, check out this story and this thread).

Level 3: Fringe contenders

Alphonce Felix Simbu (2:04:38 pb), Asefa Boki (2:05:40 pb), Tebello Ramakongoana (2:06:18 pb), Abel Kipchumba (2:06:49 pb), Conner Mantz (2:07:47 pb)

This is the group in which Mantz belongs. You wouldn’t be that surprised to see one of these guys on the podium. But for one of them to win the whole thing, they’d need a breakout race in addition to the top guys not bringing their A game. Difficult, but not impossible.

Simbu, 33, finished 5th at the 2016 Olympics and 7th at the 2021 Olympics for Tanzania, but was only 17th in Paris (though he did follow that up with a 2:04:38 pb for 4th in Valencia). Boki, 27, is making his major debut after strong runs in Xiamen (1st in 2024, 3rd in 2024) and Amsterdam (2nd in 2024). Ramakongoana finished 7th at the Olympics and just ran a 2:06:18 pb for 2nd in Xiamen in January.

Kipchumba is an accomplished half marathoner, with a 58:07 pb and recent wins in NYC (2024 and 2025) and the Great North Run (2024), but he has struggled to translate that to success in the marathon. In five marathon starts, he has just one top-7 finish (5th in Berlin in 2022 in 2:06:49).

And of course, you already know about Mantz. The one other thing to note about Mantz is that his first time running Boston (2:10:25 for 10th in 2023) was the worst of his six marathons to date. But in that race, Mantz was on pace to run 2:08:18 with just two miles to go before staggering home to the finish. And he’s much fitter now than he was then.

There’s also a wild card in the field in the form of Ethiopia’s Muktar Edris. Now 31 years old, he is more than five years removed from the second of back-to-back world 5,000 meter titles on the track. And his two half marathons in 2024 (60:52 for 5th in New Delhi, 61:27 for 9th at Al Sharqiyah) were not particularly impressive. But we have to at least mention a two-time world champion making his marathon debut.

(Did you like this Mantz analysis? We talked about his odds a lot on the podcast this week. Former HOKA NAZ Elite coach Ben Rosario most definitely thinks Mantz has a shot at winning. Go to the 1:40:54 mark of this week’s Track Talk podcast)

The Other Americans

This is a good US field. Mantz is obviously the headliner, but Boston also features the 2nd (Clayton Young), 5th (CJ Albertson), 6th (Zach Panning), and 7th (Nathan Martin) placers from last year’s Olympic Trials.

Mantz and Young have finished as the top Americans, in that order, in each of their last four marathons, and that is the most likely scenario on Monday in Boston as well — though Young has not had the easiest route to the start line. Like Mantz, he has raced two half marathons this year. Unlike Mantz, neither went particularly well. Young did run a pb of 60:52 in Houston, but that only got him 10th place on a day he was looking to run much faster. Then he was just 13th at the US Half Champs in Atlanta on March 2 in 62:38.

After that race, Eyestone said they realized Young’s lower back/hamstring chain was giving him trouble, and they have spent the seven weeks since working on strengthening it. Typically Mantz is better than Young in workouts, but they end up pretty close in the results on race day. Eyestone said that looks to be the case again for Boston.

“For the last four weeks, it was almost like Clayton had hit the reset button and now he was much closer to Conner in workouts,” Eyestone said.

CJ Albertson, 31, is coming off a career year in 2024 that included three personal bests and five marathons under 2:11, including a 2:08:17 pb in Chicago and a 7th-place finish in Boston (top American, though most of the others skipped it because of the Olympic Trials). Just three weeks after that pb in Chicago, Albertson bounced back to finish 10th in New York, but he did not use that as an excuse for getting beaten by Mantz and Young.

“I’m just honestly just not quite at that level yet to run with those guys,” Albertson said after New York.

Five months have passed since that day. Is Albertson at their level now?

Panning, who trains with the Hansons-Brooks Distance Project, is in a similar position. He finished just behind Albertson at the Olympic Trials after leading much of the way, and ran a pb of 2:09:16 in Chicago last fall.

Then there are the likes of Colin Bennie (2:09:38 pb), Brian Shrader (2:09:46 pb), Reed Fischer (2:10:14 pb), Nathan Martin (2:10:45 pb). All four are tough runners (Bennie, Fischer, and Martin were all top-10 at the Trials) but lack the ceiling of Mantz/Young/Albertson/Panning. A top-10 finish would be a great day for one of these guys.

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JG predictions

We love a good prediction at LetsRun.com, but I’m holding off until I’ve had a chance to talk to the athletes, coaches, and agents at media day on Friday. Check back for our Friday 15 podcast (available exclusively on demand as a podcast to LRC Supporters Club members, but we’ll broadcast it live on youtube/X at roughly 1 pm ET) to hear me, Robert Johnson, and Weldon Johnson share our picks.

Until then, you can listen to our early Boston thoughts in this week’s regular podcast, where we broke down Mantz’s chances and some of the big storylines with former NAZ Elite coach Ben Rosario.