Correlates of Physical Activity and Cardiorespiratory Fitness Among Racially and Ethnically Diverse People with Serious Mental Illness

Background and Purpose: Obesity and related-conditions (e.g., type-2 diabetes) disproportionately impact people with serious mental illness (SMI, e.g., schizophrenia, bipolar disorder) compared to people without SMI. Physical inactivity and poor cardiorespiratory fitness (CRF; i.e., the ability of the circulatory and respiratory systems to supply oxygen to muscles during physical activity) are key modifiable risk factors that contribute to these health disparities among people with SMI. In this study, we used baseline data of a federally-funded effectiveness trial to examine demographic, health, and mental health correlates of these risk factors in a racially/ethnically diverse sample of 314 people with SMI who are overweight/obese (BMI ≥ 25) living in supportive housing agencies.

Methods: Sedentary behavior (i.e., total minutes sitting per day) and physical activity (i.e., total minutes-per-week spent walking and proportion of participants who engaged in at least a 150-minutes-per-week of at least moderate-intensity physical activity) were measured with the International Physical Activity Questionnaire. CRF was measured with the 6-minute walking test (6MWT).  We used ordinary least squares (OLS) and logistic regressions to identify demographic, health, and mental health correlates of sedentary behaviors, physical activity and CRF.

Results: Participants were mostly male (57%), racial/ethnic minorities (82%), particularly blacks and Hispanics, with a mean age of 48 and a mean BMI of 33.  The most common lifetime mental health diagnoses in our sample were depression (75%), schizophrenia/schizoaffective disorder (56%), and anxiety disorders (50%). Thirty-two percent reported a lifetime drug use disorder.  On average, participants walked 5.9 hours weekly, and sat 9.2 hours daily. Thirty-four percent engaged in at least 150 minutes-per-week of at least moderate-intensity physical activity. On average, participants walked 316.8 meters in the 6MWT. In our models, we found that female participants, on average, spend significantly less time walking than men, and older age was significantly associated with more time spent sitting per day and fewer meters walked in the 6MWT. Poor mental health, particularly having depression, was significantly related to walking less minutes per week when compare to participants without depression. Participants with diabetes and those who perceived their health as fair/poor were more sedentary than their counterparts. In contrast, health-related quality of life was positively related to being more physically active in terms of walking minutes-per-week and engaging in at least 150-minutes-per-week of a least moderate-intensity physical activity. Self-efficacy for exercise and having an internal health local of control were a positively associated with being more physical active.    

Conclusions and Implications: Our finding illustrate how sedentary behaviors, physical activity, and CRF are not evenly distributed in a racially/ethnically diverse sample of people with SMI and are associated with multiple demographic, mental health and health factors.  Our findings suggest subgroups and factors that can be targeted to develop tailored health interventions to improve the physical health of people with SMI.