Characteristics of the differential response to exercise in adults with restless legs syndrome

Restless legs syndrome (RLS) is a prevalent, sensorimotor sleep disorder characterized by the irresistible urge to move that is temporarily relieved by movement. Despite evidence for the benefits of exercise in RLS, inter-individual variation in the response to exercise exists, whereby some people experience symptom improvement while others report exacerbations. The present study examined factors that may account for differences in perceived responses to exercise in RLS.

Participants (N = 527) completed a nationwide survey with items assessing RLS, physical activity, sedentary levels, and experiences with RLS responsiveness to exercise. Logistic regression analyses examined associations between individual characteristics (e.g., age, sex) and perceptions of improvement and exacerbation with exercise. Exploratory analyses examined characteristics associated with perceived positive responsiveness (i.e., exercise only improves RLS) or negative responsiveness (i.e., exercise only worsens RLS).

Ordinal logistic regression identified lower RLS severity (OR = 0.83, p = 0.044), higher prevalence of a condition that could cause secondary RLS (OR = 1.76, p = 0.005), lower prevalence of periodic limb movements (OR = 0.52, p = 0.001), and higher physical activity levels (OR = 1.47, p < 0.001) as significant, independent predictors of exercise improving RLS symptoms. Individual feature ordinal logistic regression identified female sex as significantly associated with exercise exacerbating symptoms (OR = 0.62, p = 0.008). Exploratory logistic regression identified people with higher BMI (OR = 0.69, p = 0.019) and higher RLS severity (OR = 0.70, p = 0.026) had lower odds of being positive responders to exercise.

The present study presents factors that might account for individual differences in the response to exercise. Overall, our results suggest that milder cases of RLS (lower severity, absence of PLMs), people with secondary forms of RLS, and those with a lower BMI may perceive exercise as more beneficial for symptoms. These should be considered in exercise-based management aimed at managing symptoms as the collective body of research supports the benefits of exercise in adults with RLS.