Unit 7 – A:C Ratio
Understanding AC Ratio
Dr. Tim Gabbett studied rugby players and published research pertaining to injury risk associated with changes in workload. During these publications Gabbett brought to the forefront what we call the Acute: Chronic Ratio (A:C Ratio for short).
Dr. Gabbett noticed that injury risk was increased when athletes were exposed to workload that caused the A:C Ratio to increase or decrease outside specified ranges. Motus Global studied this concept and introduced it via wearable technology to the game of baseball to help reduce arm injuries. The Motus sleeve has been ground breaking in its ability to seamlessly measure overall workload on baseball players daily.
Let’s break down A:C Ratio for a deeper understanding of how you can use it in your own training.
A:C Ratio takes our Acute Workload and divides it by our Chronic Workload.
As we have discussed in our previous unit Acute Workload gives us an idea of our short term window of exertion. Chronic Workload gives us a long term picture of an athletes fitness level.
Gabbett elaborated that a safe A:C Ratio range is approximately (.7 to 1.3). In accordance to Gabbett’s research if an athlete has an A:C Ratio resulting in higher than a 1.3 he is at approximately 25x higher risk of injury due to the athlete potentially having reached a fatigued state.
A:C Ratio should be thought of as a governor. It provides us framework to maintain progression of intensity to help us mitigate fatigue.
In off-season preparation for in-season play, it is important an athlete progresses his daily workload values in accordance to their effect on the A:C Ratio. Progression of daily workload values in accordance to A:C Ratio assures that an athlete mitigates fatigue in training progression. In-season it is important an athlete maintains a consistent schedule repeating daily workload values and mitigating fatigue.
This is why the combination of the Motus Sleeve and our Dynamic Throwing Program together provide the highest level of throwing protocols. The Motus Sleeve seamlessly tracks daily workload and provides an A:C Ratio. Depending on the prior throwing sustained by an athlete, the Motus Sleeve offers a daily workload value that can be used to develop daily throwing protocols. Our Dynamic Throwing Program offers multiple daily throwing options to achieve this recommended 1 day workload.
In our next unit we will show you how to progress and sustain appropriate A:C Ratio through a throwing model.