Both ‘high-dose’ and ‘low-dose’ exercises were beneficial.

Although exercise has been a longstanding guideline-recommended therapy for patients with osteoarthritis (OA), whether higher ‘dosing’ of therapy (by duration and intensity) can yield incremental improvements in symptoms, function or quality of life (QOL) is unknown. Scandinavian researchers randomised 189 patients (average age, 62 years) with symptomatic knee OA to receive either high-dose (11 exercises over 70 to 90 minutes) or low-dose (five exercises over 20 to  30 minutes) exercise therapy three times weekly for 12 weeks; all sessions were supervised by physiotherapists.

At the end of the three-month intervention and after six and 12 additional months of follow up, both groups achieved similar improvements in knee-pain scores and activities of daily living. Patients who received high-dose exercises attained significantly greater function related to sports and recreational activities at the end of therapy and at six-month follow up and significantly greater QOL benefit at six month follow up. Those incremental gains (over low-dose exercises) waned by 12 months.

Comment: This study did not include a placebo group, and some placebo-effect benefits might have occurred. It also incorporated a professional physiotherapist for the exercise training, which might not be generalisable to many patients outside the study. Nonetheless, most people with knee OA should be encouraged that even low-dose (i.e. 20 to 30 minutes, three times weekly) exercises can confer relevant symptom and function improvements, and more-active individuals benefit from extended exercise sessions.

Daniel D. Dressler

Torstensen TA, et al. High- versus low-dose exercise therapy for knee osteoarthritis: a randomized controlled multicenter trial. Ann Intern Med 2023 Jan 24; e-pub (https://doi.org/10.7326/M22-2348).