Adaptations to Training
When we “use” our bodies, our bodies adapt to the activity we are doing. The more we do, the more we are able to do. The less we do, the less we are able to do. This is essential in eliciting a training response.
When we train we want to cause stress to our body. (This may be our muscles, bones, cardiovascular system, etc.) We want to overload the system, which causes a degree of damage or micro-trauma. The body then responds by growing bigger / stronger / faster / fitter, so it can cope with that load in future. We cause stress to force adaptations.
Stress/load => damage => rest/recovery => adaptation/growth.
A lot of common gradual-onset injuries result from a failure to adapt to load.
There are a number of variables that can be multiplied to determine the total load:
The intensity of the activity is the most powerful multiplier in this list.
When we are considering total load, we also need to consider variables that make it harder for our bodies to adapt to load.
Variables that can be multiplied to determine how well we adapt to the load:
Recent research found that getting less than 8 hours sleep a day almost doubles the injury rate in athletes.
I’ve been frustrated this week by a couple of patients with Achilles problems that I thought should recover well. They’ve disappeared to go and have an injection, against my recommendation. It’s made me think about whether or not I should have made the referral myself? What are our options for injections, and do they work?
There are a range of commonly prescribed treatment options for tendinopathy, but very few are supported by quality, randomised, prospective, placebo-controlled trials.
SO WHAT DO I DO?
WHAT ABOUT INJECTIONS?
There are a range of drugs to inject into or around a tendon, depending on who you are referred to:
- Corticosteroid (A strong anti-inflammatory)
- Prolotherapy (An irritant to stimulate new tissue growth, e.g. hypertonic dextrose/glucose)
- Sclerotherapy (An irritant to decrease vascularisation, e.g. Polidocanol)
- Traumeel (A homeopathic preparation derived from arnica)
- Actovegin (derived from calf blood)
- Autologous blood (injecting your own blood into the tendon to promote healing)
- Platelet-rich plasma (blood is taken and PRP is extracted and injected to promote healing)
- High-volume injections (to damage the tissue and encourage new growth)
PROLOTHERAPY / SCLEROTHERAPY
AUTOLOGOUS BLOOD INJECTIONS
PLATELET RICH PLASMA (PRP)
WHY DO THE INJECTIONS WORK FOR SOME PEOPLE?
REGRESSION TO THE MEAN
Injections are a powerful way to administer a placebo effect. You need to see a specialist to receive it. You need to pay more money. There’s some high-tech equipment spinning the blood. Everything is set up for you to expect improvement and, in a decent percentage of cases, that’s all it takes to get better. If you believe the injection will help you then it is much more likely to work. However, the research tells us it doesn’t really matter what substance is injected, it is your belief in whether or not it will help that is the variable more likely to determine the outcome.
Have you had an injection for your tendon?
Load Management For Injury Prevention
Managing training load is crucial in injury prevention and treatment. A graphic in Tom Goon’s recent blog visualises how training load outweighs all other factors.
Historically we have advised that training loads shouldn’t increase by more than 10% a week. I’m not sure where this figure comes from. I’ve got no problem with it, it seems reasonable, and I’ve quoted it hundreds of times.
There’s a recent BJSM podcast interview with Tim Gabbett on load management for injury prevention. Specifically Tim talks about this paper:
- Billy T Hulin, Tim J Gabbett, Peter Blanch, Paul Chapman, David Bailey, John W Orchard, 2013.
It is research into fast bowlers but I think the principles apply just as well to any athlete.
They measured the acute workload of the last 7 days (and call it “fatigue”) and compare that to the chronic workload of the previous 4 weeks (which they call “fitness”).
Measuring Training Load
Or we could be more accurate and account for a mixed training program that may include a variety of hills / sprints / cross training etc, by giving each session a rate of perceived exertion (RPE) out of 10, and multiply that score by the number of training minutes:
The research subtracted the current 1-week average from the previous 4-week average and called this number the “training-stress balance”.
A negative training-stress balance increases the risk of injury 4 times.
Negative balance = 4 times risk of injury
For people that may be more vulnerable to injury I would change the 4-week average to a 6-week average, therefore, bringing the increase in load each week down from 25% to 16%.
This more cautious group could include:
- Pre-season training
- Kids going through growth spurts
- Athletes returning from injury
- Known history of over training injuries
- People without any training history
- Novel exercise modality