Physical activity and mental health: the connection between step count and depression, anxiety and quality of sleep.

While there are studies connecting everyday physical activity (PA) to mental health, they mostly use self-report measures for PA which are biased in multiple ways. Nevertheless, a realistic assessment of everyday PA is important for the development and implementation of low-threshold public health interventions. Therefore, we want to analyze the relationship between objectively measured daily steps and mental health. We included 1451 subjects from a subsample of the population-based LIFE-Adult-Study (2011-2014) with an average age of 55.0 years, 52.1% were female. We analyzed the effects of PA (step count measured via SenseWear Pro 3) on depression (CES-D), anxiety (GAD-7), and quality of sleep (PSQI). The regression analysis showed a significant negative association between low to moderate PA [Incidence rate ratio: 0.87 (0.77; 0.98)] as well as high to very high PA [0.84 (0.74; 0.95)] and depression and no significant associations between PA and anxiety [l-m: 0.98 (0.81; 1.18)/h-vh: 1.00 (0.82; 1.21)] or quality of sleep [l-m: 0.94 (0.84, 1.06)/h-vh: 0.92 (0.82, 1.03)], controlling for sociodemographic variables and personality. Low-threshold interventions that increase daily step count could be a useful approach for the prevention of depression. The use of objective PA measurement for research is highly encouraged.