In this unit we will discuss the difference between Acute and Chronic Workload…

 

Acute Workload

Acute Workload represents the short term accumulation of daily workload. Another way to say this is that Acute Workload represents the recent stimulus an athlete has incurred.

Traditionally Acute Workload has been calculated by taking an average of 1 Day Workloads over the last 7 consecutive days. In many sports this approach to Acute Workload can be beneficial.

In baseball though an issue arouse around the schedule of starters on a 5 or 6 day rotation who are given a day or 2 off. Using a 7 day window Acute Workload would drastically change mis-representing the actual Acute Workload sustained by that athlete. Motus was able to solve this with a 9 day Acute calculation.

Here is a direct quote of the issue Motus saw when calculating 7 day workloads for pitchers…

“Furthermore, when taking into consideration the real-world scenario of pitching rotations, a 7-day time window is not sufficient. Under ideal conditions, a MLB pitcher may pitch every 6th day as part of a 5 man rotation. Often times, rest days are introduced into schedules, pushing starts to every 7th day. At the minor league and college levels though, this is much more frequent, with starts occurring once every 8-days.”

To define the 9 day Acute Workload calculation Motus states…

“Acute workload in the Motus platform calculates an exponentially weighted moving average of the previous 9 days of workload”.

Motus goes on to explain the calculation of their 9 day Acute Workload works…

() = [0.7, 0.77, 0.83, 0.90, 0.97, 1.03, 1.10, 1.17, 1.23, 1.3]

Using this kernel, workloads from most recent day are multiplied by a 1.3, and workloads from previous days are multiplied by lower magnitudes, such that 8 day before most recent day are multiplied by 0.7.

Next, when computing the weighted average, all weighted values must first be summed. From here, the sum must be divided by a number of days, “N”. In standard fashion, the N = 9 days; however, in an effort to make ACR’s more usable within the first 2 weeks of usage, a dynamics divisor is incorporated. In this case, on the first day of usage, the acute N is equal to 3 days. On subsequent days, N is incremented until 9 days of usage occur.

(Linked White Paper For Further Reading)

In programming our goal with Acute Workload varies depending on the season. For example someone in an offseason will need to properly progress Acute Workloads increasing them until seasonal readiness is reached. Once an athlete is in-season our goal is to maintain consistent Acute Workloads as this will provide an athlete with the most optimal recovery within outing to outing routines.

 

The key take aways here are that Acute Workload is a metric representing a short term window and that Motus has concluded a coupled 9 day exponentially weighted Acute Workload is more accurate for baseball pitchers than the 7 day average Acute Workload used by other sports.