Sarcoma and Intra-infusion Exercise for Better Outcomes

The main goal of this clinical trial is to determine: 1) the safety and 2) feasibility of moderate-intensity, intra-infusion aerobic exercise in people receiving chemotherapy for non-resected sarcoma and 3) assess whether intra-infusion exercise acutely increases tumor perfusion. The trial aims to answer the following research questions: * Is intra-infusion aerobic exercise safe in people receiving chemotherapy for sarcoma? * Is intra-infusion aerobic exercise feasible in people receiving chemotherapy for sarcoma? * Does aerobic exercise induce acute increases in tumor perfusion? * In future work, which patient reported outcomes are relevant to explore in people receiving chemotherapy for sarcoma? Adverse event data and patient-reported quality-of-life outcomes will be compared to those of a historical control comprising patients who received chemotherapy for sarcoma within three years prior to study initiation. Participants will: * Participate in light- to moderate-intensity aerobic exercise during chemotherapy infusion (intra-infusion exercise) for the duration of their treatment protocol. * Exercise will follow a 15-minute exercise / 15-minute rest interval, totaling 30 minutes of exercise per hour of infusion. * Prior to initiating chemotherapy, undergo a single 15-minute exercise session. During peak exercise, a radioactive tracer will be injected intravenously followed by a single-photon emission computed tomography and computed tomography (SPECT /CT) scan to obtain images of tumor perfusion. A resting SPECT/CT scan will also be performed.