Physical Activity and Exercise During Early Treatment Phases for Childhood Acute Lymphoblastic Leukaemia to Protect Against Muscle Loss and Improve Frailty Outcomes

This is a small trial testing out a new approach before doing a bigger study. Researchers are observing a group of children/adolescents (ages 5-17) with acute lymphoblastic leukemia (ALL) and testing a physical activity and exercise program on a group of them who after 5 weeks of treatment show signs of weakness or frailty. Kids who are NOT losing muscle aren't part of the exercise trial - they're just monitored over time to see how they do. The goal: To see if an exercise program helps kids who are getting weaker from acute lymphoblastic leukemia treatment build back/maintain their strength, compared to kids who don't do the extra intervention. The study will also look at if this way of measuring muscle weakness works well for kids with cancer.

This is a pilot randomised controlled trial with a hybrid implementation design. In this pilot study, we are exploring a range of outcome measures to assess feasibility, acceptability, and preliminary variability. Data from these measures will inform the selection of the most appropriate primary and secondary outcomes, and estimate sample size for a future definitive trial. At 5 weeks following an acute lymphoblastic leukaemia diagnosis children/adolescents (5-17 years) will be assessed for frailty using a novel frailty framework, to evaluate their frailty risk and identify those with signs of sarcopenia. Children with signs of sarcopenia will be randomised to one of two groups: 1. Standard care only, or,2. Physical activity and strengthening intervention plus activity tracking with a Fitbit (A wearable electronic activity tracker). This study will evaluate if the implementability of this intervention as well as the limited efficacy and investigate the framework for frailty used in this study. It is known that children undergoing acute treatment for ALL experience signs of frailty from as early as 6 weeks post diagnosis. It is known that physical activity and exercise is safe and effective for children though it is most commonly conducted as a reactive therapy when children have already significantly deteriorated. Very little is known regarding the pathophysiology that drives sarcopenia in children with cancer, there is optional consent for participants to have their blood samples biobanked for future studies. There are no standardised diagnostic criteria, assessment tools or treatments for sarcopenia or frailty. Often studies limit diagnosis to imaging modalities alone, omitting functional assessment. We will use a standardised criteria incorporating muscle mass and functional measurements (such as hand grip strength). This study aims to explore factor that contribute the frailty including sarcopenia assessment ("muscle strength" and muscle mass "loss of muscle") as well as "slowness", "poor endurance", "low physical activity" The intervention aims to reduce the risk of frailty for participants with early signs of sarcopenia and currently there are no interventions that target frailty directly in children with cancer nor has frailty been investigated in the acute treatment phases of treatment.

Inclusion Criteria: * Aged 5-17 years at the time of consent * New diagnosis of acute lymphoblastic leukaemia \<7 days * Is planned to receive management for their cancer treatment at the trial site for the duration of the trial period * Has a legally acceptable representative capable of understanding the informed consent document in English and providing consent on the participant's behalf * Have a family electronic device that can be linked with the tool to be used (Fitbit) Exclusion Criteria: * none