2025 World Championships
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Swimming biomechanist Gustavo Lima from Brazil has pulled together some interesting data comparing David Popovici‘s 46.51 in the 100 free from the 2025 World Championships to Pan Zhanle‘s 46.40 World Record in the same event from the 2024 Olympic Games.
Looking beyond basic splitting, Lima broke the swims down on metrics like distance per stroke and stroke rate.
There are a few interesting things revealed by the analysis.
For one, Pan’s stroke rate starts very high, but then steadily decreases as the race goes on. Popovici’s also starts high and decreases for the first 50 or so, both at a lower rate than Pan, but at the turn the two flip. Popovici has a much higher stroke rate in the back half of the race than does Pan.
Pan, however, has a longer distance-per-stroke in the back half of the race, which helps balance out the lower stroke rate. Ultimately, Pan’s front-half nets out better than Popovici’s, and that’s the difference maker in the race.
What’s most interesting is that on average, they both have the same average stroke rate (50.7) and very similar average distance per stroke.
Both swimmers took exactly 64 strokes in the record-setting swims.
In short: the two swimmers, part of a new generation of guys who specialize in the 100 and 200 free (versus the 50 and 100) and have leaner builds than classic sprinters, swim their races very similarly. This perhaps points to a new formula for this extreme level of success in the 100 free.
Check out the data from Lima’s Instagram account below:
This is performance analysis, not biomechanics. SR and DPS describe methods of race execution, the same way split or turn intervals do. They’re not mechanical measures of angles, motion, torque, force, moment, etc.
And 46.71??
I’m done with this!!
Error! 10.43 for Pop second 25m? I don’t think so.
I want to see Popovici taking a shot at 200 free WR too from next year, this year it felt like he “only” swam fast enough to beat Hobson.
I want Popo to break both 100-200 free WR before he’s done with swimming. He’s talented enough to do it.
The second Popovici’s 25 in the table above looks wrong to me.
It is wrong!
It seems that achieving the DPS as much as possible is the crux of the issue.
That being said, it’s the natural physique features that make an elite swimmer stand out from a large school of career swimmers.
When coming to the case: vis-a-vis comparison btw. Pan vs. Popovic
Pan’s ultimate source of power stems from his ultra dexterous ankles used as premium engines to propel him by high frequent efficient kicks while swimming, as is unique and idiosyncratic to Pan only.
On floppy side, Popovic has an outstanding arm spread that renders an large so-called ape-index readily convertible to a long DPS.
Now the comparison reduces to a straightforward question, which feature is more enviably effective, Pan’s… Read more »
Very insightful! I wonder whether this can, at least to some extent from a technical perspective, explain Pan’s performance volatility, as well as his struggle for 200m individual event?
As you described, Pan’s unique technique is featured by his powerful and efficient turbo kicks. I suppose that the more reliance on kicks/legs could perhaps consume more energy of the body, just as the premium engines for a car. Could that be one of the reasons for Pan always trying to save as much as possible during prelims and semis apart from a tight schedule of 2 individuals events + many relay races?
In case he is not in a good enough shape, he needs to save for the second 50m… Read more »
The biomechanics are always very interesting.
I would love to see this comparison widened to include Alexy, Chalmers, Cielo and Dressel.
that would be awesome too
The thing that jumped out at me the most about Pan when watching underwater video was how his pull seems more like a distance stroke (shallow under the body with more bend at the elbow than most sprinters) while still keeping body rotation to a minimum.
Forgot to add that his arm recovery sweeps out wider than most, likely as a part of using less shoulder rotation, and my theory is that having almost no hip rotation is a big part of his kick being probably the best in the world right now.