Wow! What a great idea Jae, thanks for the inspiration. Hope to become my own New Diane one day!

Great job Jae.

This new format is brilliant Jay. Keep it up.. Good Things 🤞🏼 🙏🏼

You're a genius for being able to explain to the rest of the world about Obiri's exceptional ability to leverage her elbows.

For me, I feel that it's a great way to dissipate heat when you're are are open. I'm not a pro, though interesting in what you think. You said it was hot

made it 5 minutes...died of boredom... moving on

Amazing explanation. Thanks. I've got it exactly in my right knee - couple of weeks maybe, and only on easy runs, additionally - as soon as I increase the speed - the discomfort and pain fade away within a few minutes. I knew it has something to do with the technique and gait. Lack of knowledge is filled. Sounds pretty straightforward and logical. Gotta have some drills to test that.

If your breathing can handle then I'd go for straight posture, creates cross tension at the front, elastic energy.

Great analysis, thank you for sharing. I look forward to more from you!

This was a good one, specially the comparison of the top3 at the same time. I always watched Abdi since he was trying to break the Netherland marathon record early in his career, running far behind the Kenyans and Ethiopians. It's amazing how much he got better since joining the Nike NN running team (using PEDs or not). One thing that stuck with me through all these years is his arched back or Chest out. He could definitely run faster if he would relax his upper body. On the other hand, I'm amazed by how much Kamworor was affected by his accident with a motorcyclist. He was always competing for the top spots before. Now he seems to not be able to stay with the leaders at the end of races.

Do you wear your glasses when you run?

km당 속도 5분, 6분대인 일반 러너 자세도 분석해주세요.

Mam please tell how to breathe while training for marathon, or running a marathon there is lot of confusion i am not able decide whether to breathe with nose or mouth, because some says breathing through nose would tired to you and some says breathing through mouth is bad i am very confused

It would be intersting to see footage at, say, mile 12, and compare that, given the obvious lack of fatigue so early in the race, to see if any form degredation occurs. Love your work Jae.

A random one, I always remember Shalane Flanagan running New York in 2017 and her form was super smooth. Just struck me at the time how efficient she seemed.

Nice footage, And explanation!

I was so hoping you’d use a profile shot that included Albert Korir and his extraordinarily low knee lift and heel kick. How he can run 4:50 pace while looking like an old man shuffling along had always amazed me.

PS for fun here's a full-speed clip that must have been shot directly across the street from my videographer: kzbin.infoXn8cK-nT0Dg?si=Hs1vyfiJJJ1Z_wRU

so smooth and much less head movement than 2nd place ..

What else do you see in Nageeye's form?

Your intuition here is sharp, and you’ve identified an important nuance. When running coaches and other experts reference ground reaction forces like “2.7 times body weight,” they’re often simplifying complex biomechanics, potentially leaving out crucial details-such as the time duration of these forces. Let’s unpack why the “for a few milliseconds” part is essential and whether it truly matters in terms of biomechanics. Why the Time Factor in GRF is Critical 1. Peak Force vs. Sustained Force: • The peak GRF (often cited as multiples of body weight) occurs in just a fraction of a second. Because of this short duration, it doesn’t fully capture the biomechanical stresses on muscles, bones, and joints in the same way as a sustained force would. • Sustained forces, like standing still with a load, are very different from peak forces. A brief, high-magnitude force applied over a very short time doesn’t strain the body in the same way a continuous load does. 2. Impulse and Force Absorption: • The body can tolerate high peak forces over short periods due to its ability to absorb and distribute impact. Muscles, tendons, and ligaments work together to spread out and dampen the force. • If GRF were exerted for a long duration, the joints and bones would experience much greater stress and be at a higher risk of injury. But, in reality, the body is highly adapted to handle these short-lived impacts through elastic recoil and active control by muscles. 3. Why Emphasizing Duration is Important: • Omitting the “milliseconds” detail can mislead people into overestimating the mechanical load per stride. Hearing “2.7 times body weight” makes it sound like the body sustains that force, which can imply a high injury risk if form is slightly off. • In truth, correct running form helps reduce the time of peak impact and optimizes how the body handles these forces. It’s not just about reducing GRF, but about improving how efficiently the body responds to these brief peaks. What Really Matters in Biomechanics: The Bigger Picture 1. Force Distribution and Alignment: • Good running form helps align the body to optimize force distribution, minimizing the risk that any single structure (like the knee or ankle) will bear an excess load during that peak impact. • Techniques like slight forward lean, relaxed arm swing, and proper foot placement help manage both the impact duration and distribution of force. 2. Load Tolerance and Adaptation: • The body adapts to repeated high peak forces, especially with progressive training, by strengthening muscles, tendons, and ligaments to tolerate short bursts of load. • These adaptations make the brief peak forces from running less risky than they might sound. So, framing GRF without acknowledging adaptation can indeed give a misleading sense of the impact risk. Simplified Messaging in Coaching When a coach says, “Run this way because the impact is 2.7 times your body weight,” they’re likely trying to emphasize that improper form can amplify peak forces or prolong impact duration, potentially increasing the injury risk. But skipping the time factor oversimplifies the point and risks misunderstanding: • Misinterpretation: People might think they’re “slamming” into the ground with massive forces, which could lead them to overcorrect or run unnaturally. • Overemphasis on GRF: Many other factors, such as muscle strength, flexibility, and cadence, influence injury risk more than GRF alone. Final Thoughts The “2.7 times body weight” peak force, applied over a few milliseconds, does matter in biomechanics but not in the way it’s often portrayed. It’s less about the raw force and more about how the body handles it. Proper form helps make those milliseconds of impact manageable by controlling force distribution and absorption across the joints and muscles, rather than reducing the peak force itself. So yes, omitting the time factor misses a crucial part of the picture, as you pointed out. Peak GRF sounds dramatic, but for a trained runner, those milliseconds of impact are a standard part of efficient, low-risk movement.

Illustrative analysis and comparison with her previous races. Just a thought, how likely is it really that a seasoned world class runner in the 30's changes her running form either consciously or subconsciously? I'm thinking rather it may be the new version of the shoes causing her longer stride length and the higher cadence? There's hasn't been much/any data published on the Nike AlphaFly as compared to the more studied Vaporfly. Some small number studies show that the benefit in running economy/oxygen consumption is somewhat greater in the AlphaFly than in the Vaporfly but it's also been shown that the variability between individuals is big. Cheptngetic has used the AlphaFly before but not the third iteration which she raced in now, in a marathon I believe and I guess it's safety to say that each new version of this shoe should be somewhat better than the previous versions, so maybe it's the shoe causing this change in form? Either way, it's still really an outlier performance and it's crazy to think that with a more sensible pacing she might run even faster.

Mam please tell how to breathe while training for marathon, or running a marathon there is lot of confusion i am not able decide whether to breathe with nose or mouth, because some says breathing through nose would tired to you and some says breathing through mouth is bad i am very confused

Love this tip!

Do they manufacture Performance Enhancing drugs in Kenya? If they cheat someone must be manufacturing and supplying them to Kenyans. Who is that? What is it for for him/her😂😂😂

I’m here because I thought running was good for you and now I have runners knee and it’s not improving.

Once it’s proved it’s not PED then you will say she’s an Alien!

That's not how Chepng'etich is pronounced, it's actually very easy once you hear it. Great analysis though

Her pacers were effortlessly floating in sync

Can you analyse Tigst Assefa

It took me sometime, but I finally got to watch your video. It was great analysis, so thanks you 👍 Here are a few things I observed : - Her hands raise too high for my liking (compared to pacers). This could tire her biceps and shoulders - Her right hand doesn't cross the middle of her body. - Her right foot is almost straight forward when it lands. It should be a bit turned to the right

I’m finding myself paying more attention to the pacers’ form than Ruth’s. They are running exactly the same and perfectly in sync!

You really think she's done it from you?I don't think so.She's a cheat

Drugs is how she did it. A very sad day in marathoning.

Very interesting but Ruth wasn't concerned with any of what you discussed, she trained harder, prepared smarter, and some luck was on her side during race day. PERIOD!🤔

Sub 2:10!? WOW! Great analysis, btw 😁

Ruth Chepngetich has no idea what you're talking about but keep talking

amazing analysis thank at 75yrs old learnt so much about running at elite standard this record is crazy almost not possible progression on womans times beyond all experts expectations

Jealous people saying she cheated..... 🥴🥴🥴Come to Kenya 🇰🇪🇰🇪🇰🇪🇰🇪🇰🇪 and see how we do it. Here in Kenya, we EAT, DRINK and SLEEP running 🎉👌💪💪💪💪💪

Check her video when she ran the world championship

With such a result, all questions are for sports medicine. They have already found something, but there is no control yet.

Great analysis. Thanks!

Thanks Jae! I remember you saying that running is a ball sport, with the head being the ball!😉

PED's she from Kenya, no way she is clean.

I wish you were able to draw on the still shots and then clear the drawing as you resume play. There must be a program for that

This was an incredible analysis, thank you!

Micro dosing EPO for years. Undetectable.

We c African runners run on TALENT and the West treats running as a SCIENCE . U either got it , or u aint !

I presume some of the improved cadence and stride length is from increased fitness and maybe higher mileage. Also the pacing in Chicago this year was on point for her. It takes a serious level athlete to pace a sub 2.10 and this put her pacers around top 10 too. I think only one of them finished with her. The pacers forms are also exceptional.

All of this is simply not that important