RecruitingBehavioural interventionInterrupting Sedentary Time to Improve Cardiometabolic Health and Toxicity in Patients With Lymphoma Receiving Chemotherapy: The iSTAND TrialThis study aims to see if a 12-week exercise program designed to reduce long periods of inactivity is feasible in newly diagnosed lymphoma participants receiving R-CHOP or POLA-R-CHP chemotherapy treatments, and whether it can improve heart health and reduce chemotherapy drug side effects.