Deadlift tracking is the most-requested update we've ever had at STANCE. It also took us 18 months to build. Here's why — and what we did to get it right.
The problem
How STANCE measures bar speed
STANCE measures bar speed using an accelerometer. On squats and bench, that works cleanly: the bar travels through controlled paths and stops in a predictable way.
Deadlifts are different. When you drop a deadlift at the top, the accelerometer gets a massive shock spike. Those shocks make the data hard to interpret reliably — and unreliable data isn't useful to anyone training seriously.
How we approached it
Building our own encoders
To solve this, we needed a way to know what the bar was actually doing — independent of the accelerometer. Encoders are the most accurate way to measure bar velocity, so we built our own.
How our encoders evolved
Our encoder design has gone through several iterations. Each one taught us something new about how to capture clean velocity data in real gym conditions.
Capturing data in the wild
We travelled the UK with encoders and the STANCE sensor, running thousands of reps from lifters of different heights, builds, and skill levels in real training conditions.
Gyms we travelled to included Nottingham Strong (Nottingham) Raw Strength Gym (Warrington), Crazy Strength (Salisbury), Aberdeen Sports Village (Aberdeen), Swindon Barbell Club (Swindon), FORT (London) Gymnation (London), Bethnal Green WL (London) and many others!
Calibrating STANCE for deadlifts
We then used that data to calibrate STANCE specifically for the demands of the deadlift — the shock spike from the bar hitting the floor, the variation in setup, the fact that every rep starts from a dead stop. The goal was a device that reads bar speed cleanly, regardless of how messy the rep looks.
It took three iterations of refinement to get to a result we were happy with and this is how it works.
The results
We tested STANCE against our encoders across thousands of reps. The numbers:
- 98% rep detection accuracy
- R = 0.95 correlation against the encoder
- Average error: 0.049 m/s
By the third iteration, accuracy was at a level we were happy to ship — readings consistent enough across real deadlift sessions to support real training decisions.
What this means for you
STANCE now tracks the full powerlifting total: squat, bench, and deadlift. You can use it across your whole training week to compare warm-ups, judge top-set readiness, and track whether the same weight is moving faster over time — on every lift, not just two.
Deadlift tracking goes live on 15 May.
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