About
WHOOP for your muscles.
Recovery trackers read your heart. Repsense reads the muscle — during the set, while it works.
The problem
Every lifter guesses. Which chest exercise hits the upper pec hardest? Is the left side keeping up with the right? Did the glutes fire on that squat, or did the lower back take it? The feedback loop in strength training is feel, a mirror, and opinion.
EMG — surface electromyography — has answered these questions in labs for decades. It reads the electrical activity of a working muscle directly off the skin. But it stayed in the lab: either a hobbyist board that outputs a raw waveform, or a five-figure research rig built for clinicians.
What we built
Repsense takes professional EMG and does five things to it: simplifies it, makes it affordable, designs it specifically for strength training, translates the data into something a normal lifter understands, and turns that into a decision you can act on this set.
The result is two wireless sensors, adhesive electrodes and an app. You place the sensors, do the set, and read a score. Left against right, rep against rep, week against week.
The honest metric
Surface EMG cannot tell you that exactly 87% of a muscle fired. So Repsense does not claim to. Instead it returns a Muscle Score — a normalised 0–100 figure calibrated to your own maximum, comparable to your own history. It is the most useful number we can stand behind, and no more.
Where we draw the line
Repsense is a training-analytics tool. It is not a medical device, and it is not built to diagnose, treat, prevent or rehabilitate any condition. We keep our claims to what the signal can support: activation, symmetry, consistency, fatigue and change over time.
The line we work to
Push. Measure. Repeat. The instrument speaks; it does not cheer. The number carries the meaning — our job is to make it trustworthy, and to keep everything else out of the way.