But that's who I Am: The inability to enact physical activity identity is associated with depression and anxiety symptoms

There is strong evidence to suggest that physical activity reduces depression and anxiety symptoms, and recently there have been calls to consider the role of psychological determinants of physical activity behaviour as part of this effect. We investigated whether a person's physical activity identity moderated the impact of physical activity on depression and anxiety symptoms. Participants aged 19-33 years (N = 97; M = 21.8; 50.5% female, 44.3% Caucasian) self-reported their physical activity identity then wore activity monitors for six days. On the seventh day, participants self-reported their depression symptoms and anxiety symptoms. Multiple linear regression models were conducted to determine whether physical activity identity moderated the link of physical activity with prospective depression and anxiety symptoms. For people who had physical activity identity scores greater than 1.51 SD more than M, physical activity and depression symptoms were negatively associated. For people with a physical activity identity score greater than 0.52 SD more than M, physical activity and anxiety symptoms were negatively associated. For those with a strong physical activity identity, not being physically active was associated with more prospective depressive and anxiety symptoms although the effect sizes were small. It may be that there are negative mental health impacts of not being physical active for those with strong physical activity identities. Physical activity interventions targeting mental health outcomes may need to be tailored for a person's identity and provide support when people do not engage with the physical activity behaviour that they value as part of their identity standards.