Objectives: Health-related quality of life (HRQOL) encompasses a holistic examination of well-being in which health is considered a state of complete physical, mental, and social well-being. Recent studies suggest that prolonged sedentary behavior (SB) may harm to metabolic health independent of moderate-vigorous physical activity (MVPA). Thus, this study aimed to determine both independent and combined association of objectively measured SB and MVPA on the risk of poor HRQOL in general US population.

Methods: We analyzed data from 5359 participants (2667 males and 2692 females) aged 20 years or older from the National Health and Nutrition Examination Survey 2003-2006. HRQOL was measured using a HRQOL-4 that consists of four questions focused on the self-perception of general health, physical health, mental health and activity limitation. SB and MVPA were measured using a uniaxial accelerometer. We also created a categorical variable using a combination of SB tertile by MVPA tertile.

Results: We observed that SB was marginally associated with general health (P for trend=0.088) and significantly associated with activity limitation (P for trend=0.007). MVPA was also associated with poor general health (P for trend=0.002) and physical health (P for trend=0.003) after fully adjusted for potential confounders. Compared to the high SB/low MVPA, there was a substantial decrease of the risk of poor overall HRQOL in individuals with moderate SB/high MVPA (OR: 0.56 (95% CI: 0.40-0.78)) or low SB/high MVPA (OR: 0.69 (95% CI: 0.51-0.94), but there was no significant decrease in those with high SB with high MVPA.

Conclusions: SB and MVPA were independently associated with poor HRQOL components, respectively. Moreover, our findings suggest that prolonged SB may weaken protective effect of MVPA on the risk of poor HRQOL.