Family history of cancer as a cue to action for physical activity behaviour and beliefs.

Examine if family history of cancer serves as a cue to action prompting adults to assess their personal risk of cancer, consider the consequences, and engage in physical activity (PA) if they believe it will reduce their risk. Cross-sectional survey of adults with and without a close relative with cancer. Health Belief Model (HBM) constructs of perceived cancer vulnerability, perceived cancer severity, response effectiveness of PA, self-efficacy for PA, and barriers to PA, and moderate-to-vigorous intensity PA (MVPA). Perceived barriers and self-efficacy correlated with MVPA in both groups ( < .05), and perceived vulnerability and response effectiveness correlated with MVPA in participants with a close relative with cancer ( < .05). In multiple regression analyses, HBM constructs accounted for 18.5% and 8.3% of the variability in MVPA among participants with and without a close relative with cancer, respectively. Participants with a close relative with cancer had greater perceived vulnerability to cancer compared to participants without a close relative with cancer ( < .001). Adults with and without a close relative with cancer may be differentially influenced by HBM constructs, and as a result may respond differently to PA interventions and public health messaging.