For most of my career, the standard advice given to individuals with cancer was simple: rest, eat what you can, and focus on getting through treatment. It was well-intentioned. It was also incomplete. The science has moved. We now have consensus-level evidence that structured exercise during active cancer treatment is not only safe for most adults but also meaningfully improves outcomes. The 2022 American Society of Clinical Oncology (ASCO) guideline on exercise, diet, and we