PURPOSE: There is increased demand for lifestyle interventions earlier on the cancer continuum (i.e., during curative-intent treatment). To address this need, researchers face unique challenges intervening in the short period of time after diagnosis, but before initiation of chemotherapy and/or surgery. During the peak of the COVID-19 pandemic, transitions to remote/digital platforms became both mandatory and immediate. METHODS: This case study details the rapid transition to a remote/digital study embraced by our team as we recruited patients newly diagnosed with breast cancer to a pilot study. The pilot's purpose was to characterize the relationships between physical activity (PA) and cognitive and mental health during breast cancer treatment. RESULTS: We reflect on the lessons learned during this pilot study with a particular focus on three emergent challenges: digital data collection, recruitment during active breast cancer treatment, and participant burden. We used a systematic implementation framework to track adaptations made to meet the evolving needs of patients and clinicians, while adhering to institutional protocols. CONCLUSIONS: This case study provides important insights into the delicate balance between patient, clinician, and institutional needs in the breast cancer setting, particularly when delivering digital interventions during treatment. IMPLICATIONS FOR CANCER SURVIVORS: Careful attention should be paid to protocols for remote research to ensure that it is feasible, acceptable, and rigorous for all cancer survivors.