The aim of this study was to investigate the dose-response relationship between physical activity and health-related quality of life (HRQoL) in a large population-based sample of people with chronic disease. We analysed the data of 29,271 adults (15,315 women) who were diagnosed with chronic diseases and participated in the Welsh Health Survey (Wales, UK; data collection 2011-2015). Participants were classified, based on their weekly minutes of moderate-to-vigorous physical activity (MVPA), into four groups as follows: inactive (no MVPA), insufficiently active (<150 min/week), sufficiently active (≥150-<300), and very active (≥300). The main outcome was HRQoL measured via the Short-Form 36 Health Survey (SF-36). This study found a curvilinear association between MVPA and HRQoL and a dose-response relationship for the perception of general health and vitality domains. Compared to inactive participants, those who were very active had higher HRQoL scores (coefficient = 12.54; 95% confidence interval [CI] 11.39-13.70), followed by sufficiently active (coefficient = 11.70; 95% CI 10.91-12.49) and insufficiently active (coefficient = 9.83; 95% CI 9.15-10.51) participants. The fully adjusted regression model showed curvilinear associations between MVPA and the domains of SF-36. Future research should find ways to motivate people with chronic diseases to engage in physical activity. The evidence to support regular exercise in individuals with chronic diseases in all age groups is strong and compelling, and patients should be encouraged to regularly devote more time to physical activity in order to improve their health and well-being.
Keywords: COPD; SF-36; cancer; cardiovascular disease; chronic disease; diabetes; exercise; health survey; health-related quality of life; physical activity.