How OAC Built a Competitive Marathon Team in Boulder

OAC’s marathon team is taking shape

Joe Klecker arrived at the On Athletics Club in Boulder six years ago focused on track racing. Coach Dathan Ritzenhein saw a longer road ahead. Klecker’s physiology, persistence, and genetics, Ritzenhein believed, pointed toward the marathon—and the potential to excel there. The club began in 2020 with eight post-collegiate runners pursuing Olympic places from 1,500 to 10,000 meters. Several, including Klecker, reached the Tokyo Games, and OAC athletes later won medals in Paris. Track was the start of Ritzenhein’s plan, though. Since then, he and coach Laura Thweatt have built a road program to match. Hellen Obiri helped establish OAC’s marathon credentials after joining in 2022. The Kenyan great is a four-time [Major Marathon](https://www.runnersworld.com/races-places/a73532906/guide-to-world-marathon-majors-entry/) winner and the women’s [New York City Marathon](https://www.runnersworld.com/races-places/a74285249/new-york-city-marathon-course-guide/) course record holder. Her success, alongside Klecker’s 2:05:56 marathon best from Boston and the arrival of Ryan Ford (2:05:46) and Patrick Kiprop (59:14 for the half marathon), has made the group a serious presence on the roads. That growth matters because marathon running can be a lonely business. OAC’s four athletes are preparing for New York with teammates who can challenge, steady, and teach one another. We visited the OAC Global Training Facility in Boulder to see how the team’s training, coaching, and shared experience have contributed to that progress.

1. Use your teammates’ strengths

When Obiri moved to Boulder in 2022, she was shifting from track racing to the marathon. Her training load rose from about 80 miles a week to 120–125, with demanding sessions such as 25K [tempo runs](https://www.runnersworld.com/advanced/a20827239/what-is-a-tempo-run/). That change called for more than physical adaptation. She needed training partners who could help her adjust to the volume and sustained effort. At the time, OAC had no other marathoners. Obiri ran parts of her [long runs](https://www.runnersworld.com/training/a73669222/marathon-long-run-duration/) with 10,000-meter runner Alicia Monson, and joined Klecker for longer tempo efforts and fartleks. The arrangement helped all three: Obiri went on to win New York and Boston twice and take Olympic bronze in Paris; Monson set American records in the 5,000 and 10,000 meters in 2023; and Klecker got an early look at the demands of marathon preparation before his [first marathon](https://www.runnersworld.com/beginner/a73487793/tips-from-first-time-marathoners/). Klecker remembers how different Obiri’s long runs felt from a track runner’s easy day. “[Obiri’s] level is so high that, on a lot of our long runs and even some fartleks, we would overlap for a good chunk of those workouts,” the 29-year-old told *Runner’s World*. “And for me, it was harder than I thought. When you’re racing on the track, a long run is kind of a chill day because all of your hard work is on the track. But when you’d see her go out and do her long runs, she was just hammering from the start, and so I knew I really had to wrap my head around this new way of training for the roads.” As Klecker approached his marathon debut last fall, the club brought in Ford as his main training partner. Their schedules didn’t fully line up at first: Ford was building toward the [Chicago Marathon](https://www.runnersworld.com/news/a74055320/chicago-marathon-results-2026/), while Klecker was targeting New York a month later. They trained together for Boston, including key workouts, and both saw better race execution and substantial time improvements. Kiprop, 25, joined more recently after winning the Lilac Bloomsday 12K and Peachtree Road Race 10K. The former University of Arkansas runner ran 59:14 in his half-marathon debut in Houston in January, then moved to Boulder in early August to join Klecker and Ford for the 12-week New York buildup. Klecker’s first marathon was largely a matter of getting through the distance. He planned to hold 5:00 pace and let the leaders go when the pace surged on First Avenue. His strength paid off later, as he passed runners [fading in the final miles](https://www.runnersworld.com/training/a73512965/marathon-mental-tips/). The team’s target has changed this year. Klecker, Ford, and Kiprop have used hard long runs and [marathon-specific workouts](https://www.runnersworld.com/training/a71241597/race-day-pace-workouts/) to prepare for the surges and uneven pacing common at the front of the New York race. Klecker wants to be in that front group, with a chance at the podium. “This year, the goal is to be up front and try to race for that podium and not just catch the people who die. You can’t do that from two minutes back late in the race,” he said. “Now, based on the training we’ve done through a natural progression of workouts, it feels I should be ready to go with some moves. That's kind of been the whole focus of the past year, to be more competitive throughout the race.” Training partners can sharpen an athlete’s work. They can also tempt that athlete to go too hard. Obiri, 36, arrives in New York as defending champion after running a personal best of 2:15:53 for second at the [London Marathon](https://www.runnersworld.com/news/a71127180/london-marathon-results-2026/) in April. Because she has sometimes pushed too hard alongside faster teammates, OAC has brought in Kenyan partners closer to her pace for parts of the past two years. This season, that’s Dennis Kipkosgeu, who has a 2:13 marathon best. Obiri calls this her best buildup yet, and says the larger road group has changed her daily training. “The growth of our road running team feels amazing because I have runners to train with every day,” she said. “When I joined in 2022, I was the only marathoner, and that was hard. This gives me confidence because there are four of us working so hard together.”

2. Build trust in the coaching

By early 2025, Ritzenhein wanted someone to run the road program day to day. He and assistant coach Kelsey Quinn were focused on the track group, which included [Yared Nuguse](https://www.runnersworld.com/news/a63718626/yared-nuguse-indoor-mile-world-record/), the Paris Olympic bronze medalist in the 1,500 meters. Thweatt had just retired from professional running and posted on Instagram that she was looking for her next opportunity. Ritzenhein called two days later. Within roughly two weeks, she was coaching OAC’s marathoners. Her résumé included a 2:25:38 marathon, two fifth-place finishes at U.S. Olympic Trials—the marathon in 2020 and 10,000 meters in 2016—and top-ten results in London and New York. Even so, Thweatt initially questioned what she could teach athletes faster than herself. During the early stages of the New York buildup, she ran with Obiri several days each week; as the sessions got faster, she paced from a bike. The job, she found, went well beyond setting workouts and tracking results. A coach can draw on experience, ease pressure, build confidence, help athletes [visualize](https://www.runnersworld.com/training/a45990390/visualization-techniques/) race-day scenarios, keep their attention on the process, and make sure easy days stay easy. Those details matter over the long haul of marathon training. Thweatt describes the coach as the person who brings the work together. That role, she says, matters for runners at every level. Kiprop has leaned on his coaches and teammates during his first marathon build. Their advice has helped him feel more prepared than many first-timers: Klecker, Obiri, Ford, Thweatt, and Ritzenhein have all run their first marathons on New York’s five-borough course, and can share firsthand advice about the route and race-day logistics. “At first, I didn’t know if I could handle the [training for the marathon](https://www.runnersworld.com/training/a73531198/20-week-beginner-marathon-training-plan/),” he said. “But with time, as you train together, you build that confidence, you build the courage to face the marathon.”

3. Support the work beyond running

Ritzenhein became OAC’s first coach in 2020, just weeks after his final professional race. He wanted to build a program that could last beyond one Olympic cycle, which meant investing in patience, a supportive team culture, and the right facilities. OAC Global now has 20 athletes from eight countries. Since 2024, the team has operated from a 10,000-square-foot training center eight miles north of downtown Boulder. It brings training, fueling, strength work, and team communication under one roof. Just as useful, it gives athletes a place to build relationships during the months of demanding marathon preparation. Kiprop sees the facility as a home base for the team. “I think coming up with this facility was a genius idea,” he said. “It has everything we need. It’s nice to have your team around you here. When we’re together, it feels like family.” The center includes two antigravity treadmills, eight Woodway treadmills, an underwater treadmill, and e-stim machines, used mostly for bad weather and rehabilitation. Athletes can also see massage therapists and physiotherapists, meet with coaches, dietitians, and mental strength counselors, or use a lounge with a mini kitchen stocked with drinks, snacks, and supplements. There’s a full gym for [strength training](https://www.runnersworld.com/training/a73413732/strength-training-guide-for-runners-schedule/), drills, and strides. Strength coaches Jason Ross and Joslynn Peterson lead sessions twice a week, combining running-focused work with general [strength exercises](https://www.runnersworld.com/training/a74049730/runner-strength-training-workout/). For a marathon squad, that breadth matters: the race demands enough fitness to cover 26.2 miles, but the support around that running can shape how well athletes handle the training itself.

Strength work and fueling have to survive contact with race day

The less visible parts of marathon training may matter as much as the headline workouts. OAC runners start strength blocks with longer isometrics, then shift toward heavier loads and fewer repetitions. Their routines vary, but can include weighted box step-ups, single-leg bent-knee hamstring holds, trap bar deadlifts, landmine single-leg Romanian deadlifts, seated calf raises and weighted standing calf raise holds. Coach Thweatt’s point is plain: strength work is part of training, not an optional add-on. Teammate Thweatt says athletes can’t afford to become complacent about staying healthy and strong. The same practical thinking shapes fueling plans. Working with sports dietitians, each OAC marathoner uses sweat testing and training data to estimate calories burned and fluid and sodium lost, then plan what to replace during long or hard sessions. The needs differ by runner. They practice taking gels and collecting bottles, too, so they know how long to carry them and how to drink from them. Thweatt says the team rehearses its fueling strategy in almost every training session, down to what goes into race-day bottles. After 12 weeks of practice, the aim is for runners to follow the plan without having to think through every step on race day. That’s a sensible standard: a plan that works only on paper isn’t much of a plan.

A nine-day cycle makes room for recovery

Most marathon plans run on a seven-day week. OAC’s group used a nine-day cycle during its 12-week buildup to Boston and New York, fitting three long or hard sessions around two or three easier days. The schedule doesn’t align neatly with calendar weeks, but Thweatt says the extra recovery helps athletes absorb demanding workouts while training at 5,400 feet. The group’s mileage reflected individual backgrounds and preferences. At the peak of the New York build, weekly totals ranged from 118 to 135 miles. Klecker started training in early July to increase his volume and topped 130 miles several times in the fall. Ford and Obiri settled near 120; Kiprop, whose previous average was 100, ran about 110. Long runs supplied much of that volume: 35K (22 miles) and 40K (25 miles), including several at 8,500 feet on Magnolia Road, west of Boulder. On four late-cycle 40K runs, Klecker, Ford and Kiprop began around 5:45 per mile, reached 5:30 by 20K, then ran most of the second half near 5:20, sometimes finishing close to 5:00 pace. Those numbers are striking. But the recovery days are what make the workload more than a collection of big sessions. After key long runs, athletes typically cover about six miles “super easy,” between 7:15 and 6:45 pace. Thweatt has pushed Klecker and Obiri in particular to keep those runs relaxed. The next two days include double runs: 10 miles in the morning and five in the afternoon, then 12 and six. Between major workouts, the group often goes three days without faster running while still building time on feet and allowing the body to recover. Thweatt calls the long runs the training’s “bread and butter,” but says easy running is what helps the athletes take in the work. Recovery gets less attention than a fast session, she says, because it’s less flashy. That may be exactly why it deserves more.

New York rewards runners who can change gears

The OAC workouts aim to prepare athletes for the race they’ll actually run. Tempo efforts of 10 to 12 miles often start at 5:00 pace and get faster; Kiprop recently finished one at 4:45. Long fartleks alternate 1K hard at 2:50 to 2:55 (about 4:35 to 4:40 per mile) with 1K easier at 3:10 (about 5:05 per mile). Thweatt says those shifts train runners to stay uncomfortable for extended stretches and then change pace, as they may need to do in a marathon. Late in the build, track sessions added another gear: two sets of 1,600, 1,200, 800 and 400 meters at roughly 5K pace. For OAC’s men, that means 4:20, 3:12, 2:06 and 1:02, with the second set slightly faster. Ford says this approach marked a change from his earlier marathon training, which leaned heavily on marathon-pace running. He believes that strategy helped only to a point. When he ran 2:08 to 2:09, he says, he often raced apart from the front pack; now he can stay with it and compete more effectively. At 29, he has credited the faster work with cutting 71 seconds from his half-marathon best, to 59:48 in January, and more than two minutes from his marathon best in Boston. He also ran a 25K version of the 1K-on, 1K-off fartlek, including a 1:03 half marathon in the middle. That shift fits New York’s demands. Chicago, Berlin, London and Valencia are mostly flat courses, where an even pace can carry a runner a long way. New York rolls, and pace changes can reshape the race. Ritzenhein and Thweatt argue that runners need to find quicker-cadence running quickly as terrain and competitors demand it. The first 16 miles may be run at a steadier clip, but the lead packs can split on the 3.5-mile rolling, slightly uphill stretch along First Avenue toward the Bronx, where front runners may push below 4:25 per mile for men and 5:15 for women. The team’s VO2 max sessions are meant to prepare for those moments. Thweatt says runners need to touch faster paces in training to have them available when a race surges; adding mileage and extending threshold or marathon-pace workouts won’t cover every demand. Ford’s goal has changed accordingly: he wants to race the front group in New York, where runners will spend time both slower and faster than marathon pace. That’s the clearest lesson in this training approach. The volume is enormous, but the plan isn’t built around mileage alone. It combines strength, practiced fueling, recovery and speed changes that reflect the course. If you’re training for New York, the useful question isn’t only how fast you can hold a pace. It’s whether you can change it when the race asks you to.