Associations of light and moderate-to-vigorous physical activity with health-related outcomes: findings from the FINFIT 2017 and 2021 studies

Health associations of moderate-to-vigorous physical activity (MVPA) are well-established, but those of light physical activity (LPA) are much less studied. This study analysed associations of LPA and MVPA assessed both in absolute and relative terms with predicted maximum oxygen consumption (VO2max), perceived health, physical and mental quality of life (QoL), and depressive symptoms. The study is based on pooled data of two cross-sectional population-based FINFIT studies. PA was measured by a triaxial hip-worn accelerometer among 20–69-year-old adults (N = 3587, 62% women). VO2max was predicted by the 6 min walk test and analysed in sex- and age-group-specific tertiles. Other outcomes were self-reported. Absolute LPA was defined as 1.5–2.9 metabolic equivalents (METs) and MVPA as ≥3 METs. Cut points for relative LPA were ≥1.5 METs and <40% of oxygen uptake reserve (VO2R), and for MVPA ≥40% of VO2R. Data were analysed by general linear model (GLM) multivariate analysis adjusted for sex and age-groups. In absolute terms, participants spent daily 3.6 h in LPA and 48 min in MVPA. In relative terms, the corresponding times were 4.1 h and 19 min. Participants with the poorest fitness accumulated less absolute and relative LPA, less absolute MVPA, and more relative MVPA than those with better fitness (p < 0.001). Longer daily times of absolute and relative LPA and absolute MVPA were associated with better perceived health, mental and physical QoL and fewer depressive symptoms (p < 0.05). Daily time of both absolute and relative LPA and absolute MVPA was associated with better predicted VO2max, perceived health, QoL and fewer depressive symptoms, whereas relative MVPA indicated the opposite or no association. Higher amount of light physical activity was beneficially associated with estimated maximal cardiorespiratory fitness and perceived health and quality of life regardless of individual fitness level.Absolute and relative intensities of physical activity offer different but complementary utilities.Light physical activity may have health-related potential regardless of individual fitness level, but regarding more intense activity, it would be reasonable to utilize relative intensities whenever possible. Higher amount of light physical activity was beneficially associated with estimated maximal cardiorespiratory fitness and perceived health and quality of life regardless of individual fitness level. Absolute and relative intensities of physical activity offer different but complementary utilities. Light physical activity may have health-related potential regardless of individual fitness level, but regarding more intense activity, it would be reasonable to utilize relative intensities whenever possible.