How does exercise training reduce pain?
Meta-analysis shows contribution of placebo in exercise for muscle and joint pain.
Prof. Daniel Belavy from the Hochschule für Gesundheit (University of Applied Sciences) in Bochum, Germany, in collaboration with an Australian research group (Dr. Clint Miller, Institute for Physical Activity and Nutrition, Deakin University, Melbourne, Australia) examined how effective exercise is for musculoskeletal pain syndromes. Their findings: in a meta-analysis of 79 studies including 4719 patients, they found exercise training improves chronic pain, but that the effect is similar to that of a placebo treatment. Their findings were published online in the journal Sports Medicine on 27. August 2021.
Chronic musculoskeletal diseases include for example chronic back pain and fibromyalgia with a common complaint of persistent pain. Exercise therapy is a strongly recommend treatment. However it is not known whether this success is due to a placebo effect or a natural improvement in pain over time. A placebo effect is where an improvement in symptoms is seen without a known effective treatment, such as when tablets without the active medication are given.
For this reason the research team conducted a systematic review of the literature with a meta-analysis. 79 individual studies compared exercise to no exercise, but only 4 of these compared exercise to a placebo treatment.
"According to our findings, the effect of exercise training is the same as a placebo treatment. However, the evidence base is not as strong as necessary to make firm clinical recommendations“, explained physiotherapy professor Daniel Belavy.
„We know from other research that the process of visiting a physiotherapist for treatment, the expectations and experiences of the patient and the clinician as well as a number of other factors influence whether a patient benefits from a certain treatment“, explained Dr. Clint Miller.
"We consider it important to stress that exercise therapy is effective, and more effective than standard medical care for chronic musculoskueletal pain, but that more work is needed to understand how it works", Dr. Miller clarified.
Belavy added: "This evidence gap, which we identified, needs to be attended to urgently as it is a question of deep underlying importance. We know that exercise works, however by knowing how, we can improve and optimise this and other therapies to achieve the best possible outcomes for our patients".
In future randomised controlled trials it would be important to always consider: exercise therapy, placebo and no treatment, or usual care. Only in this way is it possible to assess how important each component is for reducing chronic musculoskeletal pain.
Prof. Dr. Daniel Belavy
Professor for Physiotherapy
Hochschule für Gesundheit
Tel. +49 234 77727-632
Miller CT, Owen PJ, Than C, Ball J, Sadler K, Piedimonte A, Benedetti F, Belavy DL (2021) Attempting to separate placebo effects from exercise in chronic pain: A systematic review and meta-analysis. Sports Medicine, doi: https://link.springer.com/article/10.1007%2Fs40279-021-01526-6