As Peres Jepchirchir and Ababel Yeshaneh raced towards the finish line of the 2022 Boston Marathon, one of the announcers observed Jepchirchir’s form looked, “like she’s about to fall over.” A short time later she left Yeshaneh behind for the last time and broke the tape.
So did Jepchirchir win despite her form or because of it?
And what of men’s winner Evans Chebet, with his strongly asymmetrical form?
Women’s Race
Peres Jepchirchir
Considering she has won the NYC, Tokyo Olympics, and Valencia marathons in the past two years, we can safely assume her performance is anything but a narrowly averted accident.
I’ve written about her form before, but in this race to understand more clearly how she’s running it’s helpful to compare her to Joyciline Jepkosgei, which you can do starting at 2:17 in the highlights video above. Jepkosgei’s form looks cleaner, but from the front you can see specifically what Jepchirchir has much more of is lateral movement.
It’s not that Jepkosgei has none, but it’s minimal. Her head moves a bit from side to side–her legs wouldn’t be nearly so well-aligned if she weren’t shifting her weight laterally from one to the other–but her emphasis is on rotation of her upper body and pelvis.
Jepchirchir, by contrast, has a very large upper-body movement from leg to leg. In my experience, a runner whose spine and ribs are supple enough to shift this easily from leg to leg runs faster with less effort. In the loose top of her running kit this looks a bit sloppy, but that’s just, you could say, a costume issue.
Jepchirchir tends to give the impression she’s laboring, digging into the road like a gardener with a shovel. But this is the kind of work that gets a return in the form of speed. We know it’s not wasted effort because she doesn’t sit back with her pelvis behind her foot in midstance. Her deep lean (and, let’s be honest, slight hunch) and high impact thus aren’t so injurious to her knees or feet but instead create more propulsion and a longer stride, as I’ve discussed before.
Molly Seidel
The kind of work that becomes wasted effort, on the other hand, is the work done not against the road but against one’s own body. Unfortunately Molly Seidel seemed to be doing this second kind of work, contracting her core muscles to visibly pull her belly in. I didn’t see that in the Olympics or other videos (for example this); it seems to be new. Even on the starting line you can see her abdomen pulled in and consequently her chest up in comparison to many of the women around her.

And here she is shortly before pulling out of the race (from about 1:50 in the highlights video).

Apparently she was struggling with pain from a hip impingement, and perhaps she even started doing this as some sort of a core stability strategy to address that injury. However this shortens the stride by requiring the hip joints to hyperextend more, and that is also quite stressful for those joints, so it’s a strategy that will backfire. It also makes it more work to maintain a given speed. So all of that may have played into the pain and fatigue that resulted in her DNF.
Ababel Yeshaneh
This analysis would not be complete without considering Ababel Yeshaneh’s virtuoso form. She obviously leans less than Jepchirchir or Jepkosgei, and since this shortens her stride she compensates with a higher stride rate–I don’t have any evidence that’s either better or worse than Jepchirchir and Jepkosgei, it’s just a different movement strategy.
Take a minute to watch Yeshaneh’s core action. It’s crystal clear in her subtly striped kit; you can clearly see her pelvis tipping and turning, and of course her upper body rotation as well. Her leg alignment is perfect and this is one reason why. In fact it’s essential for good leg alignment, as opposed to the kind of core activation strategy Seidel used which is touted as key for good leg alignment but actually compromises it.
Her armswing is the classic high Ethiopian style, with hands close to collarbones. As I’ve written before, that activates the posterior chain less on the backswing but is great for speed because it raises the center of gravity. However I was very interested to notice that as she and Jepchirchir ran uphill out of an underpass near the end of the race her arms came down to the same level as Jepchirchir’s. Always nice to have this kind of confirmation that the lower, heart-height armswing is what you want if you need to really use your glutes for propulsion.
You can watch this instinctive-seeming response from 6:13 in the video: as she runs uphill her arms swing lower and larger, and then as she crests the hill her hands rise again, and then the cycle repeats again as they go through the next underpass. I don’t think she’s doing this deliberately, I think it’s simply the responsiveness of a sensitive, versatile, and experienced nervous system. This is what true mastery of your running form looks like: appropriate spontaneous response to conditions instead of just robotically repeating the same movements no matter what.
Men’s Race
During the marathon broadcast, one of my readers sent me an email saying: ” I am watching the lead woman run by leaning, hands to the heart, moving shoulders and using their core almost effortlessly. Then I watch the men trying to use more strength and muscle but are not nearly as fluid.”
Overall I have to agree. To me the biggest factor is asymmetry, which seems more widespread than it used to be and was in especially short supply in the men’s field. I’m not sure if that’s a coincidence, my faulty memory of years long past, or a real phenomenon.
If it is real, then one possibility is that it’s due to the widespread use of super shoes. I’ve found that my clients’ asymmetries get stronger in those shoes, likely to the thick cushioning interfering with the kind of feedback from the ground that helps us regulate our movement.
Evans Chebet
Whatever the cause–and whatever the cost of dealing with their asymmetrical movement–the men still manage to run fast. Take a look at winner Evans Chebet’s form beginning at 3:45 in the video above. The first obvious thing is that his top is shifted to the left, where it stays.
In fact his whole body is turned to the left. Here’s a screenshot in which it looks like he’s turning to the left, perhaps to look behind himself. But in fact he’s running forward on the white line at this moment.

The really valuable thing to see here is how this requires him to bring his left leg forward using his inner thigh muscles in a subtle approximation of a carioca step (though this is the version I prefer).
I see this in runners more often than you’d think. You could spend a lot of time and energy trying to fix his left foot “overpronation,” but it’s the ability to turn equally right and left that would actually improve this coordination and help with any associated pain or injury.
Lawrence Cherono
Once you see the pattern I’ve described in Chebet’s form, you can start to recognize it more subtly in many other runners, including in second place finisher Lawrence Cherono. Overall his form seems generally symmetrical and smooth, but the slight asymmetry he has is basically the same as Chebet.
Take a look at these screenshots of Cherono in flight on each side and note the position of his arms.

As he prepares to land on his left foot, his right arm swings across his front to a significant degree. Now to be clear, it’s actually important that the hands swing to the midline rather than going front-to-back. However this is a bit much and, more importantly, it’s dramatically different from what happens as he prepares to land on his right foot. At that moment, his left hand stays well short of his midline, swinging more up than across.
So his overall pattern is to turn his upper body more to the left than the right, requiring him to turn his left foot outwards slightly and enlist his adductors more than on the right.
Making it easier for Cherono to turn his upper body right and bring his left arm across will reduce the overrotation to the left and allow his legs to work more symmetrically–especially if his pelvis is also moving appropriately. The same is very much true for Chebet.
Nobody is perfectly symmetrical and great running performance is obviously possible and even common despite this. Yet asymmetry does always have a cost in terms of effort and also potential injury, so as runners we all, like Chebet and Cherono, need to do the best we can to modulate our asymmetries without interfering with our mobility and fluidity. It doesn’t need to be perfect to be a joy to do and to watch.
I can’t see the videos. It says they won’t play in my country.
Sorry about that, Jane! In the age of the internet this kind of barrier is so frustrating. Best I can recommend is to just go to YouTube and search for Boston Marathon 2022 and see what’s available to you. Unfortunately I can’t tell from the US what you’re going to be able to see in the UK.
Use this one at 6:35 in Jane – https://www.youtube.com/watch?v=qb2JrpCVfOc
Hi Jae.
That is really informative and useful as always. My coach is an England elite runner and I have been encouraging him to shift his weight from foot to foot a bit more a la Bikele etc. as well as getting his hands in a better position. Your analysis is persuasive.
Also, our running club’s second fastest runner has asked me to help him and a video last week showed his left foot in the same position as Chebet’s (maybe worse!). Mind you, his form is all over the place and I am amazed he can run fast but not surprised he is constantly injured. This will be a challenge.
Many thanks for the continuing education.
Asymmetrical running form is often because of unequal leg lengths. One windmilling arm, hands held at different heights, torso rotating more to one side than the other, etc., all point to this. If the runner is unwilling to modify shoe height with a lift, then there will be rotational asymmetries somewhere else in the kinetic chain to compensate for the unequal leg lengths.
Sorry, Frederick, but I’ve seen a lot of asymmetrical runners in my practice, and it’s rare that there’s any anatomical leg length discrepancy. And even that can change, as it’s notoriously difficult to definitively diagnose. Furthermore, lifts also cause problems by changing the weight of one foot as well as the firmness and often also simply the sensation under that foot. So people who really do have a leg length discrepancy tend to feel better for awhile in a lift, then develop problems related to the lift and take it out, and then feel better for awhile… and around and around. If the discrepancy isn’t too large, it can be better just to learn how to use the two different legs as well as possible.