Rest can be used for recovery from fatigue and injury, but it’s the side effects of rest for injury management that hides a pretty grim secret.

Initial response to injury

It seems to be a fairly generic and universal response to most niggles, pains and injuries: rest.

You pause your running/gym/field training and have some time off to let things settle.

But what’s often forgotten is the side effects of rest as a way of managing injury.

While the occasional rest has its place in injury management, it’s one of my biggest frustrations as a physio – hearing the magic phrase “I had a month off but it’s no better, maybe even worse”.

To understand why resting can be so counterproductive, we need to go through the intended effects and side effects of rest.

We’ll go through the changes that occur over the course of the month.

Note that the timeframes discussed may be slightly different depending on your age and training history.

No one is immune to the effects of deconditioning!


Effect of resting for two days

After two days off, there’s mostly good effects – the side effects of rest haven’t made an appearance yet.

Muscles have a chance to recover and regain their full capacity.

Tendons and other connective tissue maintain their bounce and are still ready to run.

Acute inflammatory response, the body’s initial response to structural injury such as a ligament tear or muscle damage, is just winding down (a typical inflammatory response lasting two to three days after injury or stress).

Bone stress and bone cell recovery, like in a stress fracture and impact injury, is pretty much unchanged after only two days. The soreness it generates will ease slightly due to a lack of ongoing loading.

Your fitness is still pretty good. You’ve only just lost your peak fitness but you’d barely notice it.

So overall your body’s had a good rest. Most adverse symptoms are beginning to ease and you’re feeling better overall.


Effect of resting for one week

After 7 days off, the early side effects of rest begin to creep in.

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Your strength is beginning to decline without any challenge or stimulus to muscles.

Movement patterns (including running technique) start to get a little rusty and inefficient. Without physical rehearsal of movement, the brain’s “map” of the coordination of that movement becomes less accurate.

The elastic component that makes up the connective tissue reduces and your connective tissues (tendons, ligaments, fascia) begin to lose some of their bounce. Basically you feel a little bit less spring in your step.

Acute inflammatory response has finished days ago and soreness from ligament and muscle tears has reduced. So you “feel” better.

Bony soreness has usually eased a fair amount by this stage but the underlying bone reaction is virtually unchanged.

Fitness has dropped to a level that you’d notice. Running up a hill would be harder but you could still cruise on the flat without noticing much change.

Overall, your symptoms have reduced. But so has your capacity and tolerance to loading.

It’s the start of the side effects of rest for injury. And that’s not a good thing when you’re already carrying an injury…


Effect of resting for 1 month

One month after resting from training, the side effects of rest are starting to multiply.

#1 Strength and fitness have significantly declined as the weaker muscles shed bulk to make themselves lighter and easier to move. After four weeks without muscle stimulus, you’ve lost around 8-12 weeks of training gains and you’re still declining.

#2 Your movement patterns have lost their efficiency so tasks require more effort for less output. Your rusty brain map struggles to cope and over-activates muscles to try to compensate. That just leads to earlier muscle fatigue in weaker muscles.

#3 Your connective tissue has lost even more spring and elasticity, making movement feel flat and heavy. As the connective tissues provide rapid storage of energy for muscle power, it means you’ll need more muscle power to move. More muscle power from weaker muscles = early fatigue.

The combination of less strength, less bounce and more effort required to move all compound the issue and make it much harder, and riskier, to complete any activity.

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#4 Symptom-generating inflammation has eased off, although typically not fully resolved. But it no longer causes soreness at low loads. The tissue is still sensitive though and primed to react to any overload.

#5 Bone reactions have begun to settle, reducing in severity and soreness. Bone cell regeneration is underway and bones are repairing. However without much load, they’re adapting by being a little less heavy and strong.

#6 Your fitness has plummeted. Running easy now feels like hard work and you can’t sustain that effort for too long before needing a walk break.

So the good news is that your soreness has eased and you feel better.

But, and it’s a big “BUT”, you’re less capable of generating and tolerating loads due to all the side effects of rest including loss of strength, bounce and efficiency.

So your risk of overload is huge and the return to sporting activity is prone to re-aggravation due to early fatigue.

Overall effect of rest for injury

After a month off, you’ve achieved symptom reduction so you feel better.

But the hidden side effects of rest means you’re now more prone to injuries, both the original injury and a list of fresh injuries.

You’re now weaker, so movement and maintaining technique is more challenging.

Your movement is rusty, so it requires more effort for the same output.

Tendons can’t store as much energy, so you’ve lost your bounce and ability to build power.

And you’re less fit, so you get exhausted earlier.

With more fatigue and effort required, the side effects of rest have left you vulnerable to overload and injury.

How long until you’re back to normal after rest?

If you take a month off, there’s around three months of training required to catch up.

But you’ve got to take it slower on your return due to your injury risk associated with the side effects of rest.

So three months of training will probably take 4-6 months to achieve.

That’s assuming you don’t have any setbacks with symptom aggravation, new injuries…the list goes on.

Suddenly the month off seems like a very short sighted “solution”, right?