Jump height: accurate calculation and its link to explosive power

The vertical jump is one of the most widely used metrics in sports performance assessment. How simple it is to measure contrasts with how much information it yields when analysed properly.

Calculation methods

There are three main methods: flight time (the most accessible), force plate (the most precise) and kinematic video analysis. The Valkyria Trainer device combines accelerometry with validated algorithms to produce measurements comparable to laboratory ones under field conditions.

CMJ vs SJ: what each one tells you

The Counter Movement Jump (CMJ) assesses the reactive capacity of the neuromuscular system, taking advantage of the stretch-shortening cycle. The Squat Jump (SJ) measures pure concentric strength. The difference between the two — the elastic utilisation index — reveals how efficiently the athlete uses the elastic energy stored in tendons.

A drop in CMJ with a stable SJ is an early sign of central nervous system fatigue, even when the athlete reports no feeling of tiredness. This is one of the most valuable findings of systematic jump monitoring.

Recommended assessment frequency

For acute fatigue detection: 3 jumps before every intense training session. For adaptation tracking: 1 weekly test in a rested state. The individual baseline matters more than population normative values.