Prolonged Overnight Fasting and/or Exercise on Fatigue and Other Patient Reported Outcomes in Women With Hormone Receptor Positive Advanced Breast Cancer

Participants will undergo a 12-week program of prolonged overnight fasting (POF) during which they will abstain from consuming food or drink after 8pm, and wait 12 to 14 hours before resuming eating the next day. Participants will fast overnight for six nights each week, with one night off, and log their fasting start and stop times and timing of food intake daily via text messaging, or via study-provided app accessible by web browser or smart phone, or via paper journal returned by mail at the end of each month. Participants will also complete one weekly session with a health coach to review their fasting log and any barriers to and/or facilitators of meeting the POF goals. Sessions may be delivered in-person, by telephone, or by video call based on participant preference. Sessions will last 15 to 30 minutes each, for a total of 12 sessions. Participants will be provided with a notebook with information and support to encourage meeting the POF goals.

Participants will undergo a 12-week program consisting of three weekly sessions of moderate-to-vigorous aerobic and resistance exercises, under the supervision of a health coach. Sessions may be delivered either in-person or virtually via telehealth. Sessions will be tailored to the individual participant based on fitness level and symptoms at study entry, and limited to daylight hours as much as possible. Each session will last 30 to 50 minutes, as tolerated by the participant, for a total of 36 sessions. Participants will receive a Fitbit device to track their activity, and to provide heart rate monitoring during each session. Participants without access to wi-fi will be loaned cellular-enabled tablets to allow them to participate in telehealth sessions. Participants will also receive a notebook with information and support to encourage exercise.

Participants will receive a general health education resource manual at study entry, followed by six bi-weekly sessions with a health coach to review the information. Six topics, one topic for each session, will be selected based on topics of potential interest to a population living with advanced breast cancer, focusing on general nutrition, healthy lifestyle, and quality of life, with no discussion of prolonged overnight fasting or exercise. Each session, administered via telephone or video call, will last about 15 to 30 minutes, and have a specific topic and call script for the health coach to follow to minimize any intervention drift and/or contamination. Participants will receive a Fitbit activity monitoring device and additional study materials at the end of their participation in the study.