The real reason strength training helps reduce pain and rehab injuries | Canada Voices

If you’ve got a bum knee or a sore back or a creaky shoulder, there’s a good chance you’ll be advised to get stronger. After all, exercise is the most effective treatment for a wide range of muscle and joint problems.

But there’s a flaw in this logic, according to a group of health care clinicians and researchers writing in the British Journal of Sports Medicine. There’s plenty of evidence that exercise really works to reduce pain, but it’s not clear that increased strength is the main reason. Instead, exercise may have other rehab benefits that are more important to emphasize.

For example, knee osteoarthritis is among the most common causes of pain and disability among adults, and targeted leg-strengthening exercise is considered a primary way to treat it. It makes sense: Stronger leg muscles should take some of the load off the knee joint.

A recent meta-analysis, which pooled results from 12 studies, did indeed find that exercise reduced pain and improved physical function in people with knee osteoarthritis. But the benefits didn’t depend on how much stronger the patients got. In fact, increased strength explained just two per cent of the observed improvements.

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“It’s not nothing,” says Jared Powell, a physiotherapist at Bond University in Australia and the lead author of the new study, “but it certainly doesn’t seem to be the dominant mechanism of improvement.”

The same is true for a variety of other conditions: low back pain, rotator cuff problems in the shoulder, tendon pain in the knee or calf. In each case, studies find that strength training works, but that the benefits aren’t proportional to how much strength you gain.

Powell and his colleagues suggest several other reasons that exercise might help with these kinds of musculoskeletal pain. For example, physical activity is known to reduce inflammation throughout the body, which in turn might help ease the symptoms of inflammatory conditions like knee osteoarthritis.

A well-planned and gradual exercise routine might also help people lose the fear of movement – what clinicians call kinesiophobia – which can set in after a prolonged period of pain or injury. And it can reduce pain catastrophizing, which is the fear that minor discomfort will inevitably spiral into more serious pain if you keep moving the affected joint or limb.

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These latter explanations are harder to measure or quantify, but they reflect a growing belief among doctors and scientists that our experiences of pain depend not just on signals generated by our bodies, but also on how those signals are interpreted in our brains. And they suggest that the exact details of the rehab program you follow may not be as important as previously thought.

“The context in which exercise is delivered is probably just as important as the exercise itself,” Powell says. “A clinician who builds trust, validates the patient’s experience, and helps them reconnect with activities they value is probably doing more than any particular set-and-rep scheme.”

That’s not to say that building strength doesn’t matter at all. Powell’s physiotherapy practice focuses on shoulder pain, and resistance training is an important part of his treatment arsenal. “There’s something about progressively lifting heavier weights that can powerfully shift a person’s self-concept from ‘fragile’ to ‘robust,’” he says. “I absolutely wouldn’t dismiss that.”

But acknowledging that building strength isn’t the only goal of a rehab program has a crucial benefit: It means that your pain might improve even if you don’t seem to be getting stronger as quickly as you hoped. And it gives you some flexibility to tailor your exercise program to your own interests and goals.

“Strength changes may contribute to pain outcomes in some people, under some conditions,” Powell says, “but as one ingredient in a much broader recipe.”

Alex Hutchinson is the author of The Explorer’s Gene: Why We Seek Big Challenges, New Flavors, and the Blank Spots on the Map.