Winter treadmill sessions can protect a training plan from bad weather. The harder problem is keeping your head in the workout: speed intervals feel different when the view never changes and there’s no group to pull you along. The pros below offer a useful counterpoint to the idea that indoor speedwork is just outdoor training transplanted onto a belt. Incline, pace changes, and tighter control can give the session its own purpose.
Eight professional runners share the treadmill workouts they use to make indoor intervals productive. The first five begin with a tempo session built around changing incline, then move through hill simulation, marathon pace, and threshold work.
1. Tempo Run With Incline Play
Pro runner: Joe Klecker, a 2020 Olympian in the 10,000 meters. He debuted in the marathon at the 2025 New York City Marathon and set a personal best of 2:05:56 for 13th place at the 2026 Boston Marathon.
Klecker inherited this session from his mother, Janis Klecker, who ran the marathon at the 1992 Barcelona Olympics. Her approach gave the workout a built-in progression: first complete the distance, then increase the pace the next time. If six miles proved too much, hold the pace steady until you’re fit enough to finish the full session.
“My mom used to do this workout when she was training for the marathon in Minnesota,” Klecker tells Runner’s World. “The nice thing was, if I finished, say six miles, then the next time I did it, I’d move the pace faster, but if I was only able to get maybe five miles in, then I would know the next time I need to keep the pace there until I was in good enough shape to do the full six miles.”
He runs the work at marathon pace or between marathon and half-marathon pace. The incline adds enough load that the pace alone doesn’t tell the whole story. And because the workout is repeatable, Klecker can track how it changes over a winter.
“I keep this one at marathon pace or somewhere between marathon and half-marathon pace because the incline makes it quite a bit harder,” he says. “But this workout is fun because you could compare it over time throughout the winter to where you were, say, from December to February.”
How to do it
- Warm up with 2 easy miles.
- Run 4–6 miles at marathon or half-marathon pace. Switch between 0% and 4% incline every quarter-mile.
- Cool down with 2 easy miles.
2. Descending Fartlek
Pro runner: Amanda Vestri, who placed 15th among pro women at the 2026 Boston Marathon in 2:24:49.
For her first marathon, the 2025 New York City Marathon, Vestri ran 2:25:40 and leaned on treadmill sessions designed by former coach Pete Rea. Rea coached the now-defunct ZAP Endurance Group in Blowing Rock, North Carolina. New York’s rolling, hilly course was difficult to mimic outdoors on the flatter terrain available near her.
That’s where the treadmill earns its place: it can supply hills when the local roads can’t. “If you live near flatter terrain, or you don’t have those rolling hills, treadmill workouts can be hugely beneficial for a race like New York,” Vestri tells Runner’s World. “I think it definitely prepared me for it.”
Her favorite session alternates uphill and downhill running while the intervals get shorter and faster. The recoveries stay purposeful, too: instead of jogging slowly, runners “float” at a steady rhythm roughly 40 to 50 seconds per mile slower than the work pace. That keeps the mileage and effort accumulating.
“With this workout, you’re starting with a longer interval, and then in between, you’re not jogging but rather floating and running at a steady rhythm about 40 to 50 seconds slower, and you end up getting a good amount of mileage in,” Vestri says.
How to do it
- Warm up for 3 miles easily, finishing with 6–8 strides.
- 8 minutes at marathon pace: alternate every 45 seconds between 2.5% incline and -1.5% decline.
- Recover with 4 minutes of jogging at 0%.
- 7 minutes, 30 seconds faster than marathon pace: alternate every 45 seconds between 2.5% incline and -1.5% decline.
- Recover with 3:30 of jogging at 0%.
- 6 minutes at half-marathon pace: alternate every 45 seconds between 2.5% incline and -1.5% decline.
- Recover with 3 minutes of jogging at 0%.
- 5 minutes, 30 seconds faster than half-marathon pace: alternate every 30 seconds between 2.5% incline and -1.5% decline.
- Recover with 2:30 of jogging at 0%.
- 4 minutes at 10K pace: run at 1% incline.
- Recover with 2 minutes of jogging at 0%.
- 3 minutes, 15 seconds faster than 10K pace: run at 0.5% incline.
- Recover with 1:30 of jogging at 0%.
- 2 minutes at 5K pace: run at 0.5% incline.
- Recover with 1 minute of jogging at 0%.
- 1-minute snowball: increase speed by 0.1 every 15 seconds.
- Recover with 30 seconds of jogging at 0%.
- 2-minute snowball: increase speed by 0.1 every 30 seconds.
- Cool down for 5–12 minutes.
3. Marathon Pace Mile Repeats
Pro runner: Maggie Montoya, a professional marathoner with a 2:27:04 personal best who trains with the Roots Running Project in Boulder.
Montoya once saved the treadmill for the worst winter days of college, when ice or poor air quality made outdoor running unsafe. Having a treadmill at home—and facing those conditions more often—changed her mind. She now uses pace and incline adjustments to give indoor running a succession of small targets.
“When the treadmill feels a bit monotonous on an easy run, I will fluctuate the incline and speeds every few minutes to add a little more stimulus and give a task that goes by at shorter increments than a full run doing the same thing,” Montoya tells Runner’s World. “Workouts aren’t as bad because there are usually built-in fluctuations throughout it.”
She also changes the bookends of a workout indoors. Where she typically runs three miles for both warmup and cooldown outside, she usually makes the treadmill warmup four miles and the cooldown two.
Montoya says the belt helps her hold a steady pace instead of starting a repetition too fast. It also lets her build effort in a more controlled progression when a workout calls for it.
“I’ve been able to still nail all my workouts on a treadmill in recent years and am able to lock into a more consistent pace rather than when I might get out too fast in a rep outside,” she says. “It has allowed a more controlled progression of a workout too, when required, which I feel is valuable.”
How to do it
- Warm up with 4 easy miles.
- Run 6–8 repetitions of 1 mile at marathon pace, with a 400-meter jog between repetitions.
- Cool down with 2 easy miles.
4. More-Than-a-Mile Threshold Intervals
Pro runner: Emily Infeld, the 2025 U.S. champion, a 2016 Olympian, and a 2015 World Championships bronze medalist in the 10,000 meters.
After much of a decade training in Portland, Oregon, Infeld knows the appeal of moving a quality session indoors when cold rain, snow, or ice makes the road and track unpleasant—or unsafe. She especially likes the treadmill for the morning half of double-threshold days. The practical benefit is straightforward: music, fewer distractions, and a session she can finish quickly before a second workout.
“I have done quite a bit of work on the treadmill, I especially enjoy it for my double-threshold days for my morning session,” Infeld tells Runner’s World. “I’m not one for trying to make conditions ideal all the time, but sometimes it’s not feasible to go outside with snow and ice. It was pouring when I last did this, so it was nice to not have to deal with that on the road or track.”
“I like this workout because I can listen to music and turn my brain off, and I can get it done quickly in the morning to optimize rest for my second session,” she adds.
How to do it
- Warm up easily for 10 minutes.
- Run 4 × 1.25 miles at threshold pace at 1% incline, taking 85–90 seconds of complete rest between intervals.
- Cool down easily for 10 minutes.
5. Half-Marathon Pace Mile Repeats
Threshold miles built for the treadmill
For Reed Fischer, the treadmill’s sweet spot is sustained threshold work. He’s a Minnesota native who trains with Tin Man Elite in Boulder, and his personal bests are 2:09:47 for the marathon and 1:00:54 for the half marathon. He represented the U.S. in the marathon at the 2025 World Championships. You can follow Fischer on Instagram. After more than 15 years of treadmill workouts, Fischer has settled on threshold pace—or his own half-marathon pace—as the best use of the machine. Faster intervals, he says, can get hectic when you’re constantly changing belt speed; slower ones tend to stretch long enough to become dull. Mile repeats also land in a useful mental window: for most runners, each takes roughly five to 10 minutes.How to do it
- Warm up with 3 easy miles. - Run 6–8 x 1 mile at threshold or half-marathon pace. Increase the pace by about 5 seconds per mile, or 0.1 mph, and jog 400 meters between reps. - Cool down with 3 easy miles.A fartlek that keeps the clock moving
Frank Lara’s treadmill approach is built around time rather than distance. Lara, whose bests are 2:09:53 in the marathon and 1:01:00 in the half, trains with the Roots Running Project in Boulder, as does Montoya. Colorado’s weather and air quality have given him reason to take some runs indoors. Lara says the treadmill can make time pass quickly with a show or film on screen; he’s watched *The Big Bang Theory* and *Mission Impossible*. He also doesn’t put much stock in its displayed pace or distance, since machines may be poorly calibrated. One practical adjustment: start changing the speed a few seconds before a rep begins, because the belt takes time to catch up.How to do it
- Warm up easily for 20 minutes. - Run 8–10 x 3 minutes, beginning at marathon pace and working toward half-marathon or 10K pace by the final rep. Take 2 minutes of float recovery between intervals: slower than the work pace, but not a full jog. - Cool down easily for 20 minutes.Climbing practice without the mountain drive
For ultrarunners and mountain racers, uphill treadmill work offers a practical way to rehearse climbing without driving hours to find suitable terrain. Michael Wardian, an ultramarathoner and three-time 50K U.S. Champion, has also set a record for consecutive 50K races on all seven continents, finishing in 26:40:16. Wardian says uphill running raises the aerobic demand while reducing impact compared with flat running. It also loads the glutes, hamstrings, calves, and hip flexors—muscles used in trail climbs, mountain races, ultras, and hard hill surges. A sustained treadmill climb can train runners to stay composed under prolonged effort. For an added challenge, Wardian sometimes wears a 20-pound weight vest and slows to a 13:00–15:00 pace.How to do it
- Begin with 5 minutes very easy, around a 15:00 pace. - Run for 45 minutes at a 10:00–12:00 pace (5.0–6.0 mph) on a 15 percent uphill grade, or the steepest setting your treadmill allows.Threshold intervals as a progress check
Zach Bitter, a TrainingPeaks coach and ultramarathoner who previously held the 100-mile world record at 11:19:13, uses the treadmill to track his build toward 100-mile races. Its controlled conditions make past workouts easier to compare with current ones, and intervals break up the tedium of running indoors. Bitter measures progress by how his pace changes while his heart rate and perceived effort stay steady. At times, he adds a 6–10 percent incline to build strength. He says uphill running shortens stride, shifts the foot strike toward the forefoot or midfoot, and reduces the body’s vertical speed at landing. The aim here is lactate-threshold work. For Bitter, lifting that threshold can raise his fitness ceiling and help lower-intensity training stay productive as he approaches a 100-mile race. That’s a more useful treadmill benchmark than chasing whatever pace the console happens to display.How to do it
- Warm up easily for 15–20 minutes. - Do drills: leg swings, A-skips, B-skips, high knees, and butt kicks. - Run 4 x 20-second strides. - Complete 3 x 10 minutes at threshold pace, with a 5-minute easy jog between intervals. - Cool down easily for 15–20 minutes.Emilia Benton is a Houston-based freelance writer and editor whose work has appeared in Runner’s World, Women’s Health, SELF, Prevention, Healthline, and the Houston Chronicle, among other publications. She is an 11-time marathoner, a USATF Level 1-certified running coach, and an avid traveler.
