Abstract Survivors of childhood cancer in their thirties have exercise intolerance that mirrors values found among older adults in the general population. Exercise intolerance among survivors substantially increases their risk for early mortality, reduced cognitive function, poor quality of life, emotional distress, and sub-optimal participation in social roles. Fortunately, exercise intolerance is modifiable, even among individuals with impaired cardiac, pulmonary, and neuromuscular health. Nevertheless, survivors do not, on average, engage in exercise. Our hypothesis is that regular exercise may be difficult and/or uncomfortable for childhood cancer survivors because of underlying organ system impairments (specific impairment prevalence ranges from 15.5-37.7% in our eligible population). The premise of this proposal is that tailored interventions, designed, and supervised by a professional with appropriate expertise are necessary to help survivors with significant impairment feel comfortable and gain confidence with exercise and physical activity. These interventions need to be delivered in a way that both incorporates the initial supervision and advice that these survivors need, while minimizing disruption in their daily lives. This proposal tests the efficacy of an individually prescribed exercise intervention on exercise tolerance, with initial instruction provided at one clinical visit, and subsequent supervision and exercise progression provided remotely. This study, using an experienced multidisciplinary team (exercise physiology, psychology, cardiology, internal medicine, oncology, survivorship, implementation science experts), if effective, will move standard of care (encouraging physical activity) for exercise intolerance from its’ current state, where it is ineffective for many survivors, to a clinically actionable, practical, sustainable, relatively low cost, and generalizable intervention.

Relevance Survivors of childhood cancer in their thirties have exercise capacity that mirrors values found among older adults in the general population. This proposal tests the efficacy of an individually prescribed telehealth-based exercise intervention on exercise capacity in this population. This study has potential to move standard of care (encouraging physical activity) for exercise intolerance from its’ current state, where it is ineffective for most survivors, to a clinically actionable, practical, sustainable, and generalizable intervention.