ABSTRACT
We aimed to investigate the association of self-reported leisure-time physical activity (LTPA) over a 45-years from adolescence to late middle age mediated by LTPA in early middle age. We also explored whether LTPA in adolescence and early middle age was associated with change in LTPA during the COVID-19 pandemic. We constructed a path model employing questionnaire data from three LTPA measurements (1976, 2001, 2021) including duplicated assessment for pre- and during COVID-19 in 2021. The direct and indirect associations between LTPA in adolescence, early middle and late middle age were investigated, as well as the impact of previous LTPA on change in late middle age LTPA due to the pandemic. The number of participants per assessment was: n = 2083; n = 1468 (71% of the original); n = 878 (42%) and n = 867 (42%), respectively. However, the number varied depending on the path examined. LTPA in adolescence was associated with LTPA in late middle age, although the association was not strong. LTPA decreased significantly during the pandemic. Earlier LTPA was associated with change in LTPA between before and during COVID-19 among males. This study is the first to demonstrate an association between adolescent and late middle age LTPA. However, the association across the 45-years was low.