CMJ vs Squat Jump: When to Use Which Test and What Each Tells You
Summary
The countermovement jump and squat jump measure related but distinct qualities. Choosing the right test—and comparing the two—gives you information neither test provides alone.
The countermovement jump (CMJ) and the squat jump (SJ) look similar. Both involve an athlete jumping as high as possible from a standing position. But they are not measuring the same thing, and using them interchangeably — or defaulting to one and ignoring the other — loses half the available information.
The Mechanical Difference
In a CMJ, the athlete begins from a standing position, dips into a rapid countermovement (hip and knee flexion), and immediately reverses into the jump. The downward movement rapidly stretches the hip and knee extensors, loading the stretch-shortening cycle before the concentric phase begins.
In a SJ, the athlete descends slowly to a defined knee angle (typically 90°), pauses to eliminate momentum, and then jumps concentrically from that static position. There is no pre-stretch, no elastic energy loading, and no SSC contribution.
Bobbert et al. (1996) explained why the CMJ almost always exceeds the SJ in height: the pre-stretch provides both an elastic energy contribution (via tendons and connective tissue) and an enhanced active state of the musculature at the onset of the concentric phase (via the myotatic reflex). The magnitude of this contribution varies between athletes.
What Each Test Measures
Squat jump: Concentric-only power from a fixed knee angle. This is as close to a "pure" measure of concentric force production as a field jump test offers. Changes in SJ performance over time reflect changes in concentric strength and explosive capacity.
CMJ: Total jumping ability including SSC contribution. CMJ performance reflects concentric power *plus* the athlete's ability to use elastic energy and the pre-stretch reflex. It is more sport-specific for most athletic movements, which virtually always involve some pre-loading.
The Diagnostic Value of Comparing Them
The difference between CMJ and SJ height — sometimes called the pre-load benefit or the SSC utilisation index — tells you about the quality of the athlete's stretch-shortening cycle:
- Large CMJ–SJ gap (>15%): The athlete is effectively loading and using the SSC. Their total output draws significantly on elastic mechanisms.
- Small CMJ–SJ gap (<5%): The athlete is either not pre-loading effectively (technique issue), or their SSC is poorly developed (training gap).
This comparison does not require additional equipment — just two tests and the ability to measure jump height from flight time. The information gained is disproportionately useful relative to the time cost.
When to Use Each
CMJ alone: Appropriate when tracking general neuromuscular readiness, fatigue, or training response for athletes whose sport is CMJ-dominant or involves significant reactive demand (most team sports, court sports, jumping events).
SJ alone: Less common in practice, but useful when you want to isolate concentric power changes and remove the SSC variable — for example, when assessing pure strength-to-power adaptations in a hypertrophy or strength block.
CMJ + SJ together: The highest-information option. Use at key testing timepoints to assess whether training is improving total jumping ability, concentric output, or SSC utilisation specifically.
A Practical Note on SJ Standardisation
The SJ is more technically demanding to standardise than the CMJ. The descent must be genuinely slow and the pause genuinely static. Athletes who perform the SJ with a rapid descent and minimal pause are effectively performing a low-amplitude CMJ. Use a 2–3 second hold at the bottom position and cue the athlete explicitly: "Stop completely before you jump." Without this standardisation, the CMJ–SJ comparison is meaningless.
Do both tests. The diagnostic value is in the difference.
References
Mark Fisher
Founder, Swift Performance
Mark Fisher is the founder of Swift Performance and has spent 30 years designing and building athlete testing equipment used by elite sport programmes and universities worldwide. He has worked alongside researchers and PhD candidates across biomechanics, sprint mechanics, and strength science — developing the hardware and software they use to collect and analyse performance data. His writing comes from three decades at the intersection of applied sport science and precision measurement technology.
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