Last week, we covered the training volume in part 1 of load management. If you missed it, go check it out. Today, we’re going to take a deeper dive into components of load management itself and what you as an athlete, coach or healthcare professional can do about it.
I geek out on this stuff so get ready.
Any injury ever:
FORCE/LOAD > CAPACITY
This means any force/load that exceeds the capacity of your tissue’s ability to withstand that force/load.
Enter LOAD MANAGEMENT.
The goal is simple: to protect you from injury and maximize performance
Proper training must be prescribed. Over-training and under-training both increase risk of injury.
You want to:
I’d be remiss to not give credit where credit is due: Tim Gabbett and company have been leading the front on this area and are really changing the way teams and athletes are handling training.
Now, let’s define LOAD:
It is broken down into 2 variables – external load and internal load
We use these two variables to create the:
ACUTE: CHRONIC WORKLOAD RATIO (ACWR)
This is also commonly referred to as FATIGUE compared to FITNESS. Fatigue being the acute workload and fitness being the chronic workload.
With technology nowadays, we have a number of ways to track this type of data. The most commonly cited method in the research is Session RPE (sRPE), which is time (total number of minutes) multiplied by the RPE for a given training session. The RPE is usually taken after a training session to gauge level of exertion/difficulty. This is measured as “arbitrary units” or “exertional units”.
For example, in week 5, let’s say a soccer player practices one day for 60 minutes at an RPE of 8. That gives us: 60 x 8 = 480 units. She practices 4 times during week 5 with a similar intensity. This gives us our ACUTE WORKLOAD (4 x 480 = 1920 units) for week 5.
Now we have to look at her CHRONIC WORKLOAD for weeks 1-4.
When we compare the two, you get:
1920/1808 = 1.06
Now what does this number tell us?
This ratio helps delineate whether you as the athlete are prepared for the task at hand – what you’ve done compared to what you’re prepared for – that can be a running a marathon, doing a CrossFit Open workout, playing in a professional football game or doing parkour in your living room.
In terms of injury risk, acute:chronic workload ratios within the range of 0.8–1.3 is considered the training ‘sweet spot’ where injury risk is at its lowest, while acute:chronic workload ratios ≥1.5 represent the danger zone. If you look at the trend of the curve before 0.80, you should notice the injury risk climbs back up – similar to a “U-shaped” curve. This relationship between workload and injury demonstrates that both inadequate and excessive workloads are associated with injury.
Now let’s say from the example above that week 5 workload came out to 3500 arbitrary units.
That would make the ratio: 3500/1808 = 1.94
If you don’t get this reference, we’re not friends.
This athlete is at an increased risk of injury.
When training load is fairly constant (ranging from 5% less to 10% more than the previous week) players had <10% risk of injury based on the study by Gabbett et al.
However, when training load was increased by ≥15% above the previous week's load, injury risk escalated to between 21% and 49%. This is commonly represented by ‘spikes’ in acute load relative to chronic load.
To minimize the risk of injury, we should limit weekly training load increases to <10%. There’s room to work within this, but a great starting point.
Athletes accustomed to high chronic loads have fewer injuries than those accustomed to lower loads, and this supports Gabbett’s assertion that higher chronic loads can act as a protective effect against future injury.
These two graphs give a great depiction of what happens when load is applied appropriately:
Compared to excessive load and/or lack of recovery:
This is something I use every day with my patients and athletes. I’ll look at their training program and see if there is a mismatch in training volume and load management. We start here then look to optimize other components of injury and performance training such as stress management, tissue tolerance, biomechanics, physiology, strength, power, etc. At the end of the day, ask yourself this question: Is your body prepared for the demand of the task?
Dr. Ravi Patel, PT, DPT, CSCS
Dr. Danny and Dr. Jackie's views on performance improvement, injury prevention and sometimes other random thoughts.