BarTrace

Per-rep velocity, depth and tempo for squat, bench and deadlift. Recorded on Apple Watch, analyzed on your iPhone. No account, no server, nothing leaves your devices.

BarTrace turns your Apple Watch into a barbell sensor. Start a set on the watch, lift, and your iPhone returns the numbers for that set: rep count, depth, tempo, bar velocity and velocity loss.

It is built for lifters who already train to a plan and want measurement instead of estimation. Powerlifters, strength athletes, and anyone running velocity-based or autoregulated training who does not want to buy a dedicated bar tracker.

HOW IT WORKS

1. Choose squat, bench press or deadlift on the watch and tap record.
2. Lift. Recording runs inside a workout session, so it continues with your wrist down and your phone in your bag. The session is saved to Apple Health.
3. Stop the set. It transfers to your iPhone automatically and is analyzed there.

WHAT YOU GET FOR EVERY SET

Rep count, detected from the motion signal. Range of motion in centimeters, so you can check depth consistency rep to rep. Tempo, split into eccentric and concentric duration. Bar velocity in meters per second. Velocity loss across the set, the standard cue for ending a set before form degrades. Sticking points: the moment mid-ascent where the bar slows sharply, marked on the rep.

WHAT YOU CAN LOOK AT

A bar path chart for each rep, plotting vertical against fore and aft movement. A velocity curve across the rep. Rep comparison, to see how the last rep of a set differed from the first. Workout history, grouped by day. Trends per lift over time.

ACCURACY, STATED PLAINLY

Rep count, depth, tempo and velocity are the metrics to rely on. The bar path shape is a reconstruction from wrist motion, not a camera measurement and not an absolute reading. Use it to compare reps against each other, within a set and between sessions, rather than as a precise record of where the bar was in the room. BarTrace is a training tool. It is not a medical device and it does not give medical advice.

PRIVACY

Everything is recorded, processed and stored on your iPhone and Apple Watch. Nothing is sent to a server, because there is no server. No account, no sign-up, no advertising, no tracking, no third-party analytics. Workout sessions are written to Apple Health, where they stay under your control.

REQUIREMENTS

iPhone running iOS 17 or later and an Apple Watch running watchOS 10 or later. An Apple Watch is required to record. The iPhone app does the analysis and holds your history.