Scalable Community-Based Exercise to Support Physical Activity in Cancer Care: A Hybrid Effectiveness-Implementation Study

Background/Objectives: Despite recommendations to exercise, many individuals living with and beyond cancer do not achieve or sustain recommended physical activity levels because access to structured exercise support remains limited. We evaluated the real-world delivery of a scalable, community-based exercise model designed to address this gap. Methods: We conducted a hybrid effectiveness–implementation study of a 12-week supervised exercise intervention delivered in community settings across Alberta, Canada (in person or virtual). The primary outcome was the proportion of participants meeting physical activity guidelines at one year. Secondary outcomes included physical fitness and patient-reported outcomes. Results: Among 2570 participants, completion (90.6%) and attendance (77.1%) were high. At one year, the proportion meeting physical activity guidelines increased from 24.1% to 38.9% (p < 0.001), exceeding the prespecified target. At 12 weeks, participants demonstrated clinically meaningful gains in physical fitness, including sit-to-stand performance (+2.8 repetitions; 95% CI, 2.6, 3.9) and six-minute walk distance (+39.9 m; 95% CI, 36.9, 42.8), along with improvements in patient-reported outcomes. Improvements in fatigue and quality of life were smaller among participants receiving chemotherapy. Adverse events were rare (0.5%), with all serious events occurring among participants receiving active cancer treatment. Conclusions: This study demonstrates that structured supervision and behavioural support can be delivered through scalable, community-based models integrated with cancer care and may help patients achieve and sustain recommended physical activity levels. These findings support the translation of established exercise evidence into real-world models of care while highlighting the need for additional strategies to support long-term behaviour change.