Grip strength is hand and forearm force output, typically measured with a dynamometer. It outperforms blood pressure as a mortality predictor in adults over 50.
Mechanism: Grip correlates with whole-body strength, neuromuscular function, and inflammation status. It's a proxy for system-wide resilience.
Use case: Test annually. Men should aim for >40kg (under 40 = elevated mortality risk). Train via deadlifts, farmer's carries, hangs, weighted pull-ups. Cheap dynamometers ($30) work fine.
Caveats: Don't train grip in isolation if you have any thumb/wrist issue. Don't conflate grip with general strength. It's a marker, not the cause.