PlayerLoad is the sum of the accelerations across all axes of the internal tri-axial accelerometer during movement. It takes into account instantaneous rate of change of acceleration and divides it by a scaling factor (divided by 1000).
The scaling factor is used to reduce the total value of the Accumulated PlayerLoad, thereby making it easier to work with during analysis.
This parameter tells you how much work the player did during a training session or game. It is a volume measure. The number itself is an arbitrary unit, meaning it is to be used as a scaling factor to compare the total volume of work performed.
For example, a player that has a Total PlayerLoad of 300 did 50% more work than a player that has a Total PlayerLoad of 200. This number is best used to evaluate how much work a specific player has done over time, or to compare how much work that player did in a specific training session compared to previous sessions.
What is the PlayLoad formula?
Instantaneous PlayerLoad Formula
fwd: forward acceleration
side: sideways acceleration
up: upwards acceleration
Accumulated Player Load Formula
PlayerLoad vs Distance Parameter
It has advantages over using distance as an effort metric because it accumulates during tackles, ruck work, or other non-running activities. However for an athlete whose main activity is running, there will be a strong correlation between distance covered and Player Load. This is because the heel strike force generates vertical accelerations (for example) which feed into the Player Load formula (see figure below).
Who created the PlayerLoad variable
This PlayerLoad formula was originally developed at the Australian Institute of Sport (AIS) as a proposed metric for measuring effort in a rugby union application.