Testing key pathways of the multi-process action control framework: factors associated with exercise identity in people living with and beyond cancer.

Physical inactivity is a prevalent concern among people living with and beyond cancer (LWBC). Exercise identity, a construct thought to be important for exercise maintenance, has received limited attention in survivorship research. Within the Multi-Process Action Control (M-PAC) framework, identity and habit are key reflexive processes proposed to help sustain behavior. This study examined the applicability of the M-PAC framework in people LWBC and to identify how M-PAC, clinical, demographic, and behavioral variables are associated with exercise identity. In this cross-sectional survey, participants were recruited globally via cancer organizations, social media, and research platforms. Validated self-reported measures assessed exercise (Modified Godin Leisure-Time Exercise Questionnaire), reflective processes (affective attitude, instrumental attitude, perceived capability, and perceived opportunity), regulatory processes (regulatory behaviors including self-monitoring, goal-setting, and action planning), and reflexive processes (habit and exercise identity). Structural Equation Modeling (SEM) examined model fit and relationships; regression analyses examined factors associated with exercise identity. Participants (N = 477; Mage = 48.5 ± 15.4; 69.4% female) were on average 61 months post-diagnosis. Common cancer types were breast (29.1%), hematologic (12.0%), and gynecologic cancers (11.8%). SEM indicated good fit (CFI = 0.975, RMSEA = 0.064, SRMR = 0.038). Reflective processes were positively associated with both regulatory and reflexive processes, and regulatory processes were positively associated with reflexive processes (all p < 0.001). In the final regression model, exercise identity was positively associated with higher MVPA (β = 0.62, p < 0.001), stronger habit (β = 1.30, p < 0.001), greater regulatory behaviors (β = 0.28, p < 0.001), higher perceived capability (β = 0.39, p = 0.004), more positive affective attitude (β = 0.63, p < 0.001), and older age (β = 1.70, p = 0.006), and negatively associated with BMI (β = - 1.91, p = 0.015). Among people LWBC, exercise identity was associated with habit, regulatory behaviors, perceived capability, affective attitude, higher MVPA, older age, and lower BMI. These findings are broadly consistent with the M-PAC framework and suggest that future survivorship research may benefit from exploring strategies to support exercise identity.