Association Between Physical Activity Amount and Cardiorespiratory Fitness, Sleep Quality, and Health-Related Quality of Life in Patients With Long COVID: A Cross-sectional Study.

ABSTRACT

OBJECTIVE: To investigate the association between physical activity (PA) amount and gender differences on cardiorespiratory fitness (CRF), sleep quality, and health-related quality of life (HRQoL) in individuals with long COVID. DESIGN: Cross-sectional study. SETTING: An integrated outpatient clinic for post-COVID-19 at a medical center. PARTICIPANTS: Convenience sample of patients (N=264) diagnosed with long COVID. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: PA amounts, sleep quality, and HRQoL were measured by the International Physical Activity Questionnaire, Pittsburgh Sleep Quality Index, and the World Health Organization Questionnaire on Quality of Life Short Form, respectively. CRF was evaluated through graded exercise testing. RESULTS: The participants had a mean age of 42.5±13.5 years and a mean duration of post-COVID-19 symptoms of 12.7±6.8 weeks. More than half (n=149, 56.5%) were female patients. Female participants had significantly lower CRF than male participants (P<.05). Older age and higher body mass index were associated with worse CRF and HRQoL (P<.05). Less sitting behavior and greater amounts of vigorous-intensity PA (VPA) or total PA were associated with better CRF (P<.05). In addition, greater total PA and moderate-intensity PA (MPA) were associated with better sleep quality and HRQoL (P<.05), respectively. CONCLUSIONS: Gender differences were found in CRF among patients with long COVID. Greater self-reported VPA or total PA was associated with better CRF, whereas greater total PA and MPA were associated with better sleep quality and HRQoL, respectively, in patients with long COVID. Further research is needed to explore these associations in longitudinal studies.