Load Management & the Acute:Chronic Workload Ratio

Something you will hear us talking about a LOT in physiotherapy is load management.

It is often presumed that this is just in relation to any increased or decreased loading immediately prior to or directly after your injury or pain onset. But in fact, a greater level of detail is often required to get to the cause of these pain presentations.

We consider a ratio called the acute:chronic workload ratio. This takes into account your activity and training load in the past week (acute) as well as over the past month or more (chronic). It has been consistently shown that large spikes in this ratio are associated with significantly higher injury rates. Recent research conducted on premiership soccer players has found that spikes in the acute:chronic workload ratio are associated with as much as 5-7 times greater non-contact injury risk. (1) Increased injury risk has also been found in other sports such as cricket (2), Australian football (3) and rugby (4,5) with spikes in the acute:chronic workload ratio.

So how can we avoid these spikes? There is a formula we can use to determine your workload ratio (we can help you out here!) but in simple terms, it is imperative to consider your training and activity levels over the previous 4-5 weeks when considering increasing your training load. A simple example of this is taking a two-week holiday where your activity levels may be significantly lower than usual and then returning to your “usual” activity levels straight away on return & adding higher weights / longer runs / trying out new exercise classes etc. This would lead to a greater spike in training and a potential for greater injury risk than if the increased loading was added prior to the holiday.

The key is a progressive program where you start small and gradually increase your weights used/distance covered/number of classes attended per week to allow your body to adapt to the increases in demand. The body is extremely adaptable and when planned correctly, can tolerate high volumes of training and load. It is how you get to this point of high load that determines your body's ability to tolerate it.

So what does all of this mean for you?

- Plan your activity levels to avoid acute spikes in training load

- Avoid pushing your limits straight after time out from training

- Maintaining a consistent chronic workload may help to reduce the risk of injury. This goes for the kids too. With the upcoming school holidays, remember to encourage the kids to remain active throughout if they plan on transitioning back into high volumes of training on returning to school after the holidays.

- This applies to everyone with all levels of activity, not just sporting populations - e.g. if you garden for a small amount of time regularly, but then spend the weekend intensively clearing the garden for a green waste collection, that is a spike in load too.

If you would like guidance on planning to start or increase your exercise program, get in touch on 9341 2215 or book online at www.westcoastphysiotherapy.com.au

Reference:

(1) Bowen L, Gross AS, Gimpel M, et al. Spikes in acute:chronic workload ratio (ACWR) associated with a 5-7 times greater injury rate in English Premier League football players: a comprehensive 3-year study. BJSM. Published Online First: 21 February 2019. doi: 10.1136/bjsports-2018-099422 (2) Hulin BT, Gabbett TJ, Blanch P, et al. Spikes in acute workload are associated with increased injury risk in elite cricket fast bowlers. BJSM. 2014;48:708-712. (3) Carey DL, Blanch P, Ong K, et al. Training loads and injury risk in Australian football—differing acute: chronic workload ratios influence match injury risk. BJSM. 2017;51:1215-1220. (4) Hulin BT, Gabbett TJ, Lawson DW, et al. The acute:chronic workload ratio predicts injury: high chronic workload may decrease injury risk in elite rugby league players. BJSM. 2016;50:231-236. (5) Hulin BT, Gabbett TJ, Caputi P, et al. Low chronic workload and the acute:chronic workload ratio are more predictive of injury than between-match recovery time: a two-season prospective cohort study in elite rugby league players. BJSM. 2016;50:1008-1012.

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