Squat Jump Test: what it is and how to use it

The Squat Jump (SJ) is the simpler "sibling" of the CMJ. There's no downward phase before takeoff: the athlete starts from a static semi-squat position and jumps straight up with maximum power.

Although it looks very similar to the CMJ at first glance, the difference is key: by removing the countermovement, this test isolates purely concentric explosive strength, without the help of the elastic and reflexive contribution that the prior eccentric phase provides.

What does this test measure?

It assesses concentric explosive strength of the lower body, without the contribution of the stretch-shortening cycle. In other words, it measures "how much power you can generate from a dead stop," without the extra "boost" that comes from dipping down before jumping.

Equipment needed

• Jump mat, contact mat, or camera-based vertical jump app (to measure flight time and calculate height)
• A wall or reference surface if using a more basic method (Sargent Jump style)
• Enough space to jump safely

Test protocol

1. The subject adopts a semi-squat position at approximately a 90° knee angle and holds it for 2-3 seconds without movement (the "static starting position")
2. Hands stay on the hips throughout the test to isolate leg work
3. With no countermovement at all (no further dip or pre-jump impulse), tell them to jump vertically as high as possible
4. The system measures flight time to calculate jump height
5. Perform 3 attempts with full recovery and record the best

Common mistakes

• Allowing a small "countermovement" or adjustment right before jumping (this invalidates the nature of the test — it's no longer a pure SJ)
• Not holding the starting position long enough, creating a rebound from an unstable position
• Moving the arms during the jump, adding extra momentum and overestimating leg performance
• Not comparing the SJ with the CMJ, missing the most valuable insight from this test (the gap between the two)

How to interpret the result

Population	SJ jump height
Sedentary adults	15-25 cm
Recreational athletes	25-35 cm
Trained power athletes	35-45 cm
Elite (jumpers, sprinters)	> 45 cm

The most interesting part of this test isn't its absolute value, but its comparison with the CMJ:

$$\text{CMJ-SJ Difference} (\%) = \frac{CMJ - SJ}{SJ} \times 100$$

A typical difference falls between 5% and 10%. If the difference is much larger, it indicates the athlete relies heavily on the elastic/reflexive component (good reactive capacity but perhaps less base strength). If the difference is very small or zero, it may indicate poor use of the stretch-shortening cycle, something worth addressing with plyometrics.

Relationship with other tests

This test makes the most sense when compared with other vertical jumps:

• CMJ (Countermovement Jump) Test — the SJ vs. CMJ comparison is the most valuable information from this pair of tests
• Drop Jump Test — to extend the analysis toward reactive capacity under impact

Track and monitor

For the SJ vs. CMJ comparison to make sense, you need both data points well organized by date. With Movalytics you can log the Squat Jump result alongside the CMJ in the same assessment, and the app helps you see at a glance how that percentage difference evolves across the season — one of the most useful metrics for adjusting training focus (more strength vs. more plyometrics).

Frequently asked questions

Why do I jump less in the SJ than in the CMJ? That's completely normal and expected. The CMJ takes advantage of the stretch-shortening cycle (a fast eccentric phase followed by concentric), which adds height. The SJ, starting from a static position, doesn't have that boost. What if I jump the same or higher in the SJ than in the CMJ? It can indicate poor use of the elastic/reflexive component, or a technical issue when performing the CMJ (countermovement too slow or too deep). Review CMJ technique before drawing conclusions. Do I need expensive equipment to measure this? Not strictly necessary, but it helps: a high-speed camera jump app or a contact mat gives much more reliable measurements than estimating height "by eye."