Power Training Assessment | Jump & Reactive Test

Description

Power isn’t the same thing as strength, and it doesn’t decline at the same rate — research on ageing consistently shows power drops faster than maximal strength does, which is a large part of why it’s considered one of the better predictors of functional decline in later life, independent of how strong someone still tests as. The same quality is also what separates genuine explosiveness — a sharp finishing kick, real acceleration, a full jump — from simply being strong.

This assessment measures “how fast,” in two genuinely different ways, kept separate rather than blended into one number:

Dynamic power, measured via motion sensors during an actual jump — force expressed through real movement, body-mass displacement, and (for the reactive strength test) how efficiently you convert loading into rebound through a stretch-shortening cycle.

Isometric rate of force development (RFD), measured via a calibrated dynamometer — how steeply force rises in the first fraction of a second when you push or pull against a fixed point as fast and hard as possible. No movement, no flight, no body-mass displacement — a different mechanism for producing force quickly, and one that’s often more revealing of raw neural drive precisely because movement isn’t part of the equation.

These two don’t always agree, and that’s the point — an athlete can have excellent isometric RFD but a jump profile held back by technique, or vice versa. Reading them side by side tells you more than either alone.

This is purely about output, in both forms — it does not assess movement quality or joint control, which is a genuinely different mechanism covered by the separate Neuromuscular Control Assessment.

The testing battery:

Dynamic power (motion sensors):
– Countermovement jump — vertical jump height and peak power output
– Single-leg hop — unilateral power and distance, scored left and right independently
– Reactive strength index (drop jump) — the ratio of ground contact time to jump height, measuring how efficiently you use elastic energy

Isometric rate of force development (dynamometer):
– Explosive isometric pull — rate of force development (kg/s) and time to peak force, pushing or pulling against a fixed point as fast as possible
– Explosive isometric squat — the same RFD measurement in a quad-dominant pattern, scored left and right independently

What you’ll get:
– A full written report on jump power, unilateral power, reactive strength index, and isometric RFD, left and right where applicable
– A power profile across both dynamic and isometric expressions of explosiveness, flagging any side-to-side asymmetry or a meaningful gap between the two
– Targeted training recommendations — plyometric, reactive or explosive-strength work matched to what the results actually show, useful whether the goal is athletic performance or simply staying quick and springy as you age