Load Management Part 2: The Effects of Detraining

Rugby league players pre-game warm up

The Melbourne Sports Medicine Centre's Physiotherapist Mick Hughes has shared with us part 2 of his Load Management blog:

'Earlier on this week I wrote a blog on Load Management, specifically on the topic of the acute to chronic workload ratio (ACWR). As mentioned in the blog, this was one topic that I found to be very useful in trying to manage non-contact, soft tissue "overuse" (or "under-prepared") injuries. The other topic that I found to be equally important for us working with patients/athletes with these type of injuries is the effect of detraining - and it goes hand in hand ACWR.

As the name suggests, detraining is the physiological maladaptation to reduced training loads and/or physical inactivity, and it has been shown to be a contributing factor to non-contact, soft tissue injury. This is a very real topic for all of us working with, not only elite athletes, but the amateur athlete, the weekend warrior and the sedentary office worker.

Detraining can come in the form of having an off-season holiday, or can be a product of not being able to train at 100% volume/intensity due to injury or illness. Regardless of injury or illness, decreased training loads increases the risk of injury when training rapidly resumes back to normal.

Think back to the ACWR I talked about earlier in the week. If training volume is reduced to 0% for 2 weeks because you go away on holiday, subsequently your rolling 4 weeks chronic workload is also reduced. Then all of a sudden you think you're well rested and good to go after you return from holiday, and training is resumed back to 100%. What will happen is that you're going to spike your workload and your ACWR.

A typical example of this that I see in the clinic is over a 2-week Xmas break, when the patient/athlete does nothing for 2 weeks and then resumes their normal training load prior to Xmas. They often will present with a soft-tissue or tendon "niggle"/injury in mid-late January. Below would be a simple example of their training loads for a 5 week period:

  • Week before Xmas break (1500 units),
  • Week 1 holiday (0 units),
  • Week 2 holiday (0 units),
  • Week 1 after Xmas break (1500 units)
  • Chronic Workload = 3000/4 = 750units

Then in the 2nd week after the Xmas break the acute weekly load increases by 10% from 1500 to 1650:

  • ACWR = 1650/750 = 2.2

As you can see this ACWR well and truly lays outside of the "sweet spot" (as discussed in my last blog). Even if training remained the same from weeks 4 to week 5, the ACWR would still be 1500/750 = 2.0. Remember we shouldn't panic, but we know that the patient/athlete has a significantly high risk of sustaining a non-contact, soft tissue injury 7-28 days if training isn't modified back into the "sweet spot" (ACWR - 0.8-1.3) very soon.

Unfortunately this is a very common presentation and an under-appreciated aspect of the patients/athletes strength and conditioning plan. And to be fair, you wouldn't think that taking 2 weeks off over Xmas would put you at a high risk of injury when you resume your "normal" training, but as you can see it does. It really, really does. 

The good thing about all this information is that some really smart people at the AIS have devised a "Choose Your Own Adventure" table,  that outlines time-frames it takes to safely return to normal training, based on reduced training loads. It can be found here in the "appendix" section at the end of the paper provided, and I highly recommend showing this table to any patient that has sustained an "overuse" injury not long after resuming training after an extended break. Alternatively, it is a good resource to show an athlete how long it will take for them to resume 100% training after taking a "modified break".

I'll outline 2 examples or reduced training loads and training times to reinforce what the table presents:

Athlete 1: lets assume they have a cracking holiday. They go and sit on a deserted island for 6 weeks and perform 0% exercise. What the table tells us is that they will need 13 (12.9) weeks of steady consistent training - including the 6 weeks to make up for doing nothing - to safely get back to the same fitness and strength levels that they were at before taking their break.

To put this in perspective, for an elite athlete, that is almost a whole pre-season just to get back to the same standard that they were at last year. For most professional clubs, that standard won't be good enough, and it wouldn't surprise me if they under-perform from their previous season or have an injury-plagued season because they simply cannot keep up with their fitter teammates and opponents.

Athlete 2: They go to the same deserted island, but instead of doing absolutely nothing, they chose to train at 60% volume/intensity for that same 6 weeks. From the table you'll see that it would only take them 9.5 weeks of careful and consistent training to get back to the same level prior to the break.

To be frank, 9.5 weeks is still a bloody long time to safely regain previous levels of fitness and strength, but it’s a great example of how quickly detraining can effect the musculoskeletal system, and it allows us to encourage consistent training in our athletes/patients to reduce the chances of non-contact soft tissue injuries.

It’s an even better example of how long someone who has not performed any exercise in >3 months will take to achieve their goals (whilst having a reduced risk of injury). It also allows us to have a realistic conversation with them when we sit them down to plan out their recovery timeframes from an injury that they have sustained, or plan out their fitness/health and well-being goals.

So there it is, the 2 most valuable parts (in my opinion anyway) of the Load Management Symposium broken down into 2 blogs.  The other key messages that I took away from the weekend are:

- 40% of patients that walk through your door WILL sustain a subsequent injury. Not a recurrence of their presenting injury, but a completely different injury. Eg. G2 ATFL ankle sprain. Player can't train at 100% for 3 weeks. Resumes normal training and tears calf. It ties in perfectly with both the ACWR and the detraining effect, so try to plan and predict what will happen next after an injury and "put those spot-fires out before they become infernos".

- Don't forget to consider the kinetic chain in reducing loads through an injured joint or muscle.  Eg. PFJ pain. YES, quads strength is important to look at, but also look at hip abduction/ER strength AND ankle DF ROM AND quads:hamstring ratio as well.

Well that's a wrap on load management for now.  I hope that you have all been able to take something away from these 2 blogs that you can apply to your clinical practice today or tomorrow. I also hope that I have explained it in an easy to understand manner.'

If you have any queries or would like to contact Mick, please phone 9650 9372.  Appointments to see Mick can also be made online here.