Physical Activity for Adults in the Ontario Breast Screening Program

There is "strong" evidence that physical activity (PA) can reduce the risk of breast cancer (Bernstein, 2009; Kehm et al., 2020), which is important for individuals at higher-than-average risk due to their family history or genetic susceptibility. PA can also enhance quality of life (QoL), fitness, and surrogate markers (e.g., weight) linked to cancer prognosis (Ligibel et al., 2019; Patel et al., 2019). Despite this evidence, most adults are insufficiently active, meaning they do not meet Canadian recommendations of at least 150 minutes of PA each week (Statistics Canada, 2020). This study aims to develop materials that can help increase the number of adults at higher-than-average risk who meet PA recommendations, alongside improving QoL and body mass index (BMI; a measure of one's body weight-height ratio). Participants will include individuals assigned female at birth, aged 30-69 years, at high-risk of breast cancer registered in the Ontario Breast Screening Program who will be randomly assigned to receive (1) the intervention, which includes a copy of PA recommendations (Canadian Society for Exercise Physiology \[CSEP\] recommendations for adults plus content spotlighting PA benefits) plus a PA motivation package featuring three online webinars (explaining PA benefits and how to get started), digitized PA materials (providing evidence-based tools to modify behaviour), and a digitized logbook (to track PA) or (2) only a copy of PA recommendations.