“I keep getting injured this season; I just can’t catch a break”
This is, firstly, not uncommon and, secondly, unlikely luck related, though you may feel that way.
A fairly recent article in the BJSM (the preeminent sports medicine journal) has highlighted well that standard reloading protocols used are probably over ambitious in their prescription. This seems to be increasing injury risk, during and just after return to sport protocols.
This is through no fault of clinicians in their intent but rather more related to new information and understanding regarding injury risk.
This may seem like good news, which it is for injury risk, but many athletes reading this may be disappointed to hear it means a longer return to sport protocol (which means more time without playing).
This new understanding has collateral implications for general loading and more importantly in this situation deloading. Previously time off and deloading were seen as protective in nature with respect to injury risk, particularly with regards to ‘overuse’ type of injuries (see below for a better term for these and a better understanding of them). Better understanding of loading now indicates that underloading may be as big a risk factor as overloading for injury risk, but more on this later.
What is this new information and understanding? See the next classic statement.
“You are training too much”
There have been calls to do away with the term ‘overuse injury’ in favour of ‘loading error’ and, to be honest, this seems more logical to me when these injuries are often in people not doing a great deal.
So why the change and how does this happen in people who are not doing a great deal?
The last few years have yielded a significant number of scientific papers looking into this area of injury and the prevailing picture is remarkably consistent (it rarely is in science) and very helpful to those ‘on the ground’ (often not the case in science) by putting paradigm to some of the intuitive things coaches had thought and felt for a long time.
The new paradigm that is being proposed is the ‘Acute to Chronic Workload Ratio’ (ACWR).
Let’s break this down and explain its implications.
Acute workload; generally considered the training load of the last week (or microcycle if you must)
Chronic workload; recent articles focus this on the average training load of the last month (or mesocycle if you must) but this is often extended out to 10 weeks or beyond.
Acute:Chronic workload ratio(ACWR): This is the ratio of the workload in the last week to the average workload of the last month (or more).
“So what is the story with ACWR?”
It seems the story coming out of the research is fairly consistent and boils down to the ‘Goldilocks’ principle ie you need not too much but importantly not too LITTLE loading.
The sweet spot of loading is a little variable between sports (as suggested in an article released in the last month or so in the BJSM pertaining to football/soccer specifically) but generally it is suggested an ACWR of 0.8-1.1 is considered optimal. Outside of this the injury risk starts to rise, this rise looks a little variable but is almost exponential. Just to reiterate here, this is injury RISK NOT injury RATE or incidence. So you may well ignore this advice (or have been doing so inadvertently to this point) without issue, but limiting RISK of injury is the business we are in in the sports medicine community as we cannot possibly eliminate it.
Thinking about this you can see that any spikes or troughs in loading carry through for a month or more and thus should be dealt with appropriately or avoided as best as possible. This has implications much beyond any given month of the season and in the peri-injurious period.
Increased preseason participation has been shown to be protective for injury, with this effect being more significant when examined at differing running speeds. In short; the more preseasons sessions you do the less likely you are to be injured, conversely, those who have done fewer sessions are at greater risk of injury, with this effect magnified with increasing running speeds.
The QUT/ACU hamstring group have done great work over many years pertaining to one of the most hated of all injuries in sports, the hamstring strain. Their more recent work suggests that ACWR is likely implicated in hamstring injury! This is particularly interesting as this was formerly NOT seen as a loading related injury!
“How do you measure load? “
This is a really good question with answers that are far reaching and probably a bit beyond this article. But here are some considerations. Load can be measured intrinsically or extrinsically and either objectively or subjectively.
Most in the industry quantitatively measure at least extrinsic load (think GPS data) and potentially intrinsic load also (think heart rate).
Usually this is correlated with subjective measure of intrinsic loading (rating of perceived exertion).
Interestingly talking to coaches, their anecdotal experience seems to indicate that often times intangible and more informal, subjective wellness monitoring of their athletes is more useful to them. This was recently confirmed in some research suggesting that wellness questionnaires (which are fairly standard in elite sport) are a better predictor of training status/overtraining in athletes.
This is probably a good indicator that the ‘load of life’ so to speak and/or suboptimal recovery is a factor that is an effect modifier in training. For more on this see below in the article.
“He’s so good and he never seems to get injured”
Interesting that… I wonder if the two are related. Turns out there is some good data that this is indeed the case.
So even if you are more focused on performance than injury prevention (I don’t even want to know why that would be the case) there is now an associative (at least) relationship between remaining injury free and performing.
This probably doesn’t surprise a number of readers, it stands to reason that more time spent on pure training stimulus rather than recovery and reloading stimulus has a more potent effect on performance.
“I do everything I can to prevent injuries”
I’m not going into the fact that this could be called into question of itself.
Instead I will talk about things that I believe many would not be doing/things that will aid people in this endeavour which are not necessarily standard practice.
The first point is probably most important for endurance athletes and recreationally active people. It is the concept of training monotony. There is some fairly significant indication that training monotony is a large risk factor in injuries related to loading errors. What is monotony? Monotony is the LACK of variety ie running the same route, pace and in the same footwear weekly or even daily. This must be avoided at all costs and is hugely common in the aforementioned populations, though is relatively rare in team sports.
Somewhat inversely related to this is ‘bulletproofing’ yourself so to speak. This requires a high, diverse chronic workload. Alright, I will breakdown all the buzzwords in that phrase. As mentioned previously chronic workload is accumulated over the last month (or longer to be honest, including total lifetime). Having a chronic workload is important, ensuring it is diverse is crucial too. What does that diversity entail? Strength work is probably the first issue and should come as no surprise (for ALL athletes, endurance included!!!) beyond that cross training aids this too, particularly moving in different planes of motion and in different ways. As part of this, the load of ‘life’ is important to consider and optimise too. For instance; active commuting to work, leisure time physical activity and the likes.
There is some suggestion from many coaches that loading is definitely a huge issue but there are other factors that play a role in this often not considered when thinking about athletes. This includes the load from life so to speak, for instance, work stress (physical and psychological). The other aspect or another side of this coin is recovery. I have definitely heard the opinion that overtraining is non-existent and that the issue is under-recovery. Irrelevant of its pure accuracy the statement points to an important fact; recovery is crucial. Appropriate sleep, nutrition and relaxation is of the utmost importance when training and loading the body. I personally believe our society, and as a result sports as a microcosm thereof, underemphasises anything that isn’t vigorously active and subsequently recovery and regeneration is under emphasised and poorly executed by many athletes.
“Oops, I probably did a bit much”
We have all been there. How do mitigate some of the risk here?
There has been quite a bit of research in the past 5 years or so into performance enhancement/recovery augmentation. It seems to be a bit of a case of ‘groundhog day’ so to speak, with the moral being that life is a null sum. OR phrased differently, you are robbing Peter to pay Paul. The overarching take away from research on things like antioxidant supplementation, use of compression garments and ice baths seems to be that whilst they may augment recovery they also seem to blunt response to training stimulus. Again if we use some logic, this probably makes sense, the response to stimulus causing the fatigue, if blunted, would then blunt the stimulus itself.
The specifics of when, how and what regarding the use of these modalities are beyond the scope of this article.
That said, the question remains when to use these modalities if they are seemingly negative?
This may well end of being a matter of personal preference and/or coaching staff preference.
But my advice to athletes/coaches is usually that these modalities should be used when loading has been a little excessive and recovery is of a premium even at the cost of performance gain.
This usually occurs;
- Between weeks in team sports, with or without short turnarounds, usually from mid-season onwards
- When you do a bit much in training (read; don’t listen to your coach)
- When you have competed and been stretched a bit further than you thought you would be ie overtime etc
“So what are the take home messages?”
- Loading and consistency thereof, using the Goldilocks principle was, until recently, not very well appreciated in the research, hopefully this translates into practice particularly pertaining to spikes and troughs in workload as well as return to sport protocols.
- ACWR is more useful that total load and loading related injuries are probably more of a product of change in loading rather than pure amount of loading.
- ACWR of 0.8-1.1 seems to be ideal (with some caveats around different sports and individuals).
- Measuring load is hard, it is probably a matter of trial and error to find what is ‘signal’ (meaningful information) and what is ‘noise’ (useless information). But it is definitely worthwhile to monitor wellness measures in your athletes.
- Injury prevention is important for performance; lower rates of injury are associated with better performance in both team and individual sports.
- Avoid monotony in training and develop a high chronic workload to help protect yourself/your athletes from injuries.
- Ensure you optimise recovery and manage load during periods of high ‘life load’.
- If you are overstretched during competition or need to augment recovery, techniques like compression garments and cryotherapy/ice baths may be used, but understand they may blunt adaptive stimulus.
David Lipman is a medical doctor, podiatrist and exercise physiologist. He should know better, but still runs too much and often too hard, lifts much too heavy for his goals and probably drinks too much coffee (if that’s a thing). But now he tracks his acute to chronic workload ratio and it looks like it is working.