Physical activity, acute severity and long-term consequences of COVID-19: an 18-month follow-up survey based on a Swedish national cohort.

Objective: To investigate how changes in levels of physical activity (PA) in regard to acute disease severity relate to perceived difficulties in performing daily life activities 18 months after COVID-19 infection.

Design: An observational study with an 18-month follow-up survey based on registry data from a national cohort.

Participants: 5464 responders to the 18-month follow-up survey of a Swedish national cohort of 11 955 individuals on sick leave due to COVID-19 during the first wave of the pandemic.

Outcomes: The follow-up survey included questions on daily life activities, as well as present and retrospective level of PA. Changes in PA level from before COVID-19 to follow-up were assessed by the Saltin-Grimby PA Level Scale and analysed by the Wilcoxon signed-rank test. Comparisons of groups were analysed by the Student's t-test, Mann-Whitney U test and χ. Multiple binary logistic regression was performed to assess the association of changes in PA with perceived difficulties in performing daily life activities.

Results: Among the 5464 responders (45% of national cohort), the PA level decreased. Hospitalised individuals had a lower PA level both prior to COVID-19 (p=0.035) and at the 18-month follow-up (p=0.008) compared with non-hospitalised responders. However, the level of PA decreased in both groups. A decrease in PA level increased the odds (OR 5.58, 95% CI 4.90 to 6.34) of having difficulties performing daily life activities.

Conclusions: PA levels were reduced 18 months after COVID-19 infection. A decrease in PA over that time was associated with perceived difficulties performing daily life activities 18 months after COVID-19. As PA is important in maintaining health and deconditioning takes time to reverse, this decline may have long-term implications for PA and health.