Periodizing Exercise Medicine Prescription for Patients with Cancer: A Narrative Opinion.

Exercise has emerged as an effective therapeutic strategy in cancer management. Long-term supervised exercise programs, including resistance training and aerobic training, can improve body composition and physical fitness, modulate circulating factors (e.g., hormones, cytokines), enhance treatment tolerance, and reduce side effects, potentially influencing cancer progression and reducing mortality risk. Despite advancements in exercise oncology, opportunities remain to refine exercise prescription through the integration of advanced methodologies such as periodization and autoregulatory programming strategies. Periodization, a systematic approach to organizing training over time, has demonstrated benefits in general fitness and clinical populations but is underexplored in cancer care. Emerging evidence suggests periodized exercise programs may enhance physical fitness (e.g., muscle strength and cardiorespiratory fitness) while mitigating treatment-related side effects (e.g., fatigue, loss of bone mineral density). Here, we examine the mechanisms underlying the benefits of periodization in exercise oncology and propose an updated framework for its implementation across the cancer continuum (e.g., neo-adjuvant, adjuvant, survivorship). Incorporating parallel or emphasis periodized models tailored to individual needs may optimize outcomes. These models of periodization and the use of autoregulatory programming strategies allow exercise intensity and volume to be modulated in response to patients' symptoms and fatigue, ensuring safety and adherence, while aligning with the goals established by the periodized training plan. Ultimately, future research should explore complementary strategies such as nutrition and psychological periodization. By adopting a holistic and individualized approach, clinicians can improve the effectiveness of exercise interventions and ultimately enhance the quality of life for patients with cancer.