> ## Documentation Index
> Fetch the complete documentation index at: https://docs.uplift.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Eccentric Velocity

> Average vertical velocity during the squat eccentric (downward) phase.

## Technical Details

* **Variable Type:** Discrete Metric
* **Data Type:** Float
* **Units:** m/s
* **Column Name:** `max_eccentric_velocity`
* **Aggregation:** mean
* **Precision:** 2
* **Optimal Direction:** Middle — moderate values are optimal
* **Calculation:** average pelvis vertical velocity from [Initiation](/biomechanics/activities/squat/events/initiation) to [Bottom](/biomechanics/activities/squat/events/bottom)

## Description

Eccentric velocity is the average or maximum velocity of the center of mass during the downward (eccentric) phase of the squat.
It reflects how quickly the athlete descends and can be used for tempo and loading assessment.

## Use Cases

* Tempo and control of descent
* Consistency across reps
* Comparison across squat types