Beta Program Now Open — join early adopters already training with FORJ
Features For Professionals Pricing Our Story Start with FORJ
The Solution

What ForjCore measures

ForjCore is FORJ's resistance-training sensor. It clips onto a standard weight-stack pin and records how the load moves — not only how much weight was selected and how many reps were completed. Athletes, coaches, and clinicians use those metrics for velocity-based training, fatigue monitoring, and rehabilitation documentation.

Last updated: 25 August 2026

|

In a world where the most informed wins — get the edge with unrivalled training insights.

What we measure

In most gyms, the only numbers written down are load and reps. ForjCore adds the kinematics of each repetition on a pin-loaded stack:

  • Rep velocity — how fast the load travels, used for velocity-based training and fatigue cut-offs
  • Range of motion — how far the stack moves on each rep
  • Rep tempo and consistency — timing of the concentric and eccentric portions across a set
  • Power and force production — output derived from the measured movement of the load
  • Time under tension — how long the load is moving during the set

Coaches, health professionals, hybrid athletes, and gym-goers use the same device: one sensor, live data in the FORJ app, history for the next session.

FAQ

Frequently asked questions

ForjCore measures rep velocity, range of motion, rep tempo and consistency, power, force production, and time under tension. It also supports limb-symmetry comparisons. A conventional gym log typically records only load and reps.
Movement velocity shows how fast the load is travelling on each rep. That lets coaches prescribe intensity for velocity-based training, stop a set when velocity drops (fatigue), and compare sessions without relying only on the number on the stack.

Ready to train with data?

Start tracking what actually matters.

Start with FORJ