Why Eccentric Peak Velocity Matters in Countermovement Jump Testing
- Jo Clubb
- Mar 4
- 6 min read
This post explains what Eccentric Peak Velocity (EPV) represents in the countermovement jump (CMJ), and how sports science practitioners can use it with healthy and injured athletes.
When we test a squat jump, practitioners are careful to ensure there is no countermovement, as that would invalidate the test. Yet when we perform a countermovement jump, we rarely check whether the athlete actually loaded sufficiently through the countermovement to properly challenge the stretch-shortening cycle.
One metric that may help answer this question is eccentric peak velocity (EPV).
I first heard of this metric from Dr Dan Cohen, the creator of ForceDecks. Along with Dr Morgan Williams, they have shared a series on the VALD Health Blog diving deeper into the science and application of EPV.
Consequently, I included EPV as the exploratory metric in the strategy bucket of my own CMJ analysis framework (below). Now I'm more familiar with the metric, I wanted to share my own dive into the topic on the blog and YouTube channel.
What Is Eccentric Peak Velocity?
Eccentric peak velocity represents the maximum downward velocity reached during the eccentric phase of a countermovement jump.
It has also been described in the literature and practitioner discussions as:
Peak negative velocity
Peak braking velocity
During a CMJ, athletes rapidly descend before reversing direction and producing force during the concentric phase of the jump. EPV reflects how quickly the athlete moves during this downward phase.
In practical terms, EPV provides insight into how aggressively an athlete loads into the countermovement.
This loading behaviour is critical for effectively utilising the stretch-shortening cycle. If the athlete performs a slow or shallow countermovement, the eccentric braking demands are reduced, which in turn alters the neuromuscular demands of the task. As a result, EPV can provide valuable context for interpreting other CMJ metrics.
Understanding EPV Within the Countermovement Jump
The countermovement jump consists of both eccentric and concentric phases, each of which can be further subdivided. To learn more about the phases and shapes of the CMJ curve, take a look at this two-part series.
The eccentric phase represents the entire downward portion of the jump and typically includes three subphases according to VALD:
Unloading phase
The athlete initiates the countermovement by reducing force below body weight while descending.
Yielding phase
Force begins increasing again as the athlete continues descending and prepares to reverse direction.
Deceleration phase
Force rises above body weight as the athlete actively brakes and prepares to transition into the concentric phase.
The yielding and deceleration phases together are referred to as the eccentric braking phase, as this is when the athlete actively generates braking forces to reverse the movement.
Eccentric peak velocity occurs at the point where the athlete reaches their maximum downward velocity, usually at the point of entering the deceleration phase. From this moment onwards, the athlete must produce increasing force to slow their descent and reverse direction.
Understanding this mechanical context is important because it highlights how EPV sits at a critical point within the movement.
Why Eccentric Peak Velocity Can Act as a Gatekeeper Metric
Many practitioners focus on eccentric-phase metrics such as eccentric duration, impulse, or rate of force development (RFD). However, these metrics are all influenced by how the athlete performs the countermovement.
If the athlete performs a shallow or slow countermovement, several of these metrics may change even though their underlying physical capacity has not.
For example, a slower descent may increase eccentric duration or alter rate of force development metrics without necessarily reflecting a change in the athlete’s neuromuscular capabilities.
In this sense, EPV can act as a gatekeeper metric.
Before interpreting other eccentric-phase metrics, practitioners can first confirm whether the athlete actually performed a sufficiently aggressive countermovement. If EPV is suppressed, changes in other metrics may simply reflect a different movement strategy rather than a meaningful physiological change.
Example EPV Values in Healthy Athletes
Analysis of VALD's extensive data lakehouse suggests that values around −1.2 m·s⁻¹ may represent an approximate threshold indicating that a jump has been sufficiently loaded during the countermovement in healthy male team sport athletes.
Female athletes often demonstrate slightly slower eccentric peak velocities. In some professional football datasets, typical EPV values for female players may sit closer to −1.2 m·s⁻¹, which may make a threshold closer to −1.0 m·s⁻¹ more appropriate when considering whether a countermovement has been sufficiently loaded.
It is important to emphasise that these values should not be treated as rigid cut-offs. Instead, they provide contextual reference points that can help practitioners judge whether a jump represents the intended task.
As with many monitoring metrics, EPV should ultimately be interpreted within the context of the individual athlete and their own historical data.
Why Might Eccentric Peak Velocity Be Lower Than Expected?
A lower than expected EPV can occur for several reasons, and understanding the context is essential before drawing conclusions.
Movement execution
The athlete may perform the jump incorrectly. For example, they may adopt a movement pattern closer to a squat jump with minimal countermovement.
This may occur when:
the athlete is unfamiliar with the task
instructions were unclear
the athlete was insufficiently cued to perform a maximal countermovement
In such cases, EPV can help practitioners identify jumps that may need to be repeated or excluded from analysis.
Insufficient intent
If the testing protocol requires maximal effort, a reduced EPV may simply reflect that the athlete did not fully commit to the jump. Monitoring EPV can therefore help practitioners identify submaximal efforts that might otherwise go unnoticed.
Fatigue, pain or soreness
In athlete monitoring contexts, a reduced countermovement depth may reflect residual soreness or fatigue following matches or heavy training sessions. Athletes may subconsciously avoid deep or aggressive countermovements if they are experiencing discomfort in the lower limbs.
A reduced EPV may also signal that the athlete is protecting a particular structure or experiencing pain during loading. This information may provide useful context for practitioners working within integrated performance teams, as it may prompt further discussion with medical or physiotherapy staff.
Tracking EPV During Rehabilitation
The interpretation of EPV can differ when working with injured athletes. In healthy athletes, a shallow countermovement may indicate insufficient intent or fatigue. In rehabilitation settings, however, the same behaviour may represent reduced confidence or limited loading capacity during early stages of recovery.
Rather than focusing on a strict threshold, practitioners can instead track how EPV changes throughout the rehabilitation process.
Research by Dutaillis et al. (2025), shared in the second-part of the VALD Health blog, examining CMJ performance following ACL reconstruction has shown that EPV often increases gradually, illustrated by a downward trend as we're dealing in the negative, as athletes progress through rehabilitation and regain the ability to tolerate higher braking forces.
This makes EPV a useful marker of how athletes recover their ability to decelerate body mass and reverse direction vertically during the countermovement.
Tracking EPV longitudinally can therefore provide valuable insight into how athletes regain both the capacity and confidence to load the eccentric phase of the movement.
A Practical Takeaway for Practitioners
EPV has been one of my exploratory metrics in my Countermovement jump analysis
system, and perhaps it's one worth exploring in your own setting as well.
It's giving us insight into an athlete's willingness or ability to load through a CMJ.
In healthy athletes, a slower EPV, maybe below that minus one 1.2 meters per second threshold in males might be a sign of fatigue, lacking readiness, lacking intent, or perhaps task misunderstanding.
We do generally expect a slower, eccentric peak velocity in our injured athletes, and that can represent their protective behavior and a lack of confidence that can be useful to track over time as their ability to load and challenge their eccentric capacity and stretch-shortening cycle improves in rehab.
Eccentric peak velocity offers a simple way to verify the athlete actually performed the movement in the way we intended. Before interpreting other eccentric-phase metrics, practitioners may wish to ask a simple question:
Was the countermovement sufficiently loaded?
Eccentric peak velocity can help provide the answer.
FAQs
What does eccentric peak velocity measure in the countermovement jump?
Eccentric peak velocity measures the maximum downward velocity reached during the eccentric phase of a countermovement jump.
Why is eccentric peak velocity important?
EPV provides insight into how aggressively an athlete loads during the countermovement, helping practitioners determine whether a jump was sufficiently loaded to properly assess stretch-shortening cycle performance.
What is a typical eccentric peak velocity value?
Values faster than −1.2 m·s⁻¹ have been suggested for healthy male athletes, while female athletes may demonstrate slightly slower values. However, EPV should always be interpreted within the context of the athlete population and individual athlete history.
Stay tuned for more insights on athlete testing in our series sponsored by VALD Performance. Subscribe to our blog to stay updated!
This article is support by VALD Performance. For more information, about their technology, visit their website.
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