The protocol
Why a sprinter jumps for a living
Force plates measure the exact force my legs put into the ground, thousands of times per second. Standing on them and jumping sounds simple, but the shape of that force curve is the closest thing sprint sport has to an X-ray of your engine.
The battery has three parts. The squat jump starts from a held squat with no countermovement: pure concentric power, the same quality as the first strokes off a standing start. The countermovement jump allows a quick dip first, which loads the tendons the way real skating strides do. Finally the same jump is done one leg at a time, because every skating push is single-leg by definition.
Results
Me against the group
Each metric shows my value, the group average, and where I land inside the group's spread. The shaded band covers one standard deviation either side of the group mean: inside the band is ordinary, outside it is notable, in either direction. These are the real test numbers, including the ones I'm less proud of.
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Reading the test
What the January 2026 test told me
The engine is real. From a dead-start squat jump I got 46.5 cm against a group average of 37.3 cm, roughly 1.4 standard deviations above the group, with a reactive strength index to match. For someone whose race is decided by the first metres, that static-start power is exactly the right strength to have.
The force comes slower than it should. My rate of force development and my peak force per kilogram sit clearly below the group in the squat jump. Translation: I reach a big total output, but I build it up more gradually than the group does. Sharpening how fast force rises, not just how much of it there is, is a training priority.
My left leg is doing extra shifts. The symmetry indexes in the countermovement jump lean 16 to 18 percent toward the left leg, far past the group's typical imbalance, and the single-leg jumps agree: 29.4 cm on the left against 25.3 cm on the right. In a sport where corners load the legs asymmetrically anyway, that gap is worth closing before it becomes an injury story instead of a data point.
What each metric actually means
Jump height (net impulse). Height computed from the impulse I put into the plates, the most honest way to score a jump: no flight-time tricks.
Reactive strength (RSI modified). Jump height divided by how long the push took. Two athletes can jump equally high; the one who needed less time on the ground wins sprints.
Rate of force development (RFD). How fast force builds, in newtons per second. This is the "explosiveness" number.
Relative force and power. Peak force (N/kg), peak power (W/kg) and average propulsive force or power per kilogram of body mass, so a heavier athlete can't win on mass alone.
P1:P2 force ratio. Force in the first half of the push divided by the second half: whether the push is front-loaded or finishes strong.
Symmetry indexes. Right leg versus left leg. Positive values favor the right limb, negative values favor the left. Zero is perfect balance; nobody is at zero.
Provenance
About these numbers
Where they come from. The jump battery was run and reported by Luca Cajani of speed-skating-data.com, on dual force plates with a speed-skating training group. Thank you, Luca, for measuring what most skaters only guess at.
The comparison group. Only the group's mean and standard deviation are published here. No other athlete is named or identifiable.
Freshness. Each block shows its own test date. When I retest, the new results appear here through the same pipeline, next to the old ones.