Eligibility criteria
Inclusion Criteria:
* INTERVENTION (SURVIVORS) INCLUSION
* Histologically confirmed prostate cancer or breast cancer without evidence of metastatic disease
* Confirmed by review of the electronic medical record (EMR) and subsequently recorded in Survivor Health History. In cases where the EMR isn't clear, their Oregon Health \& Science University (OHSU) provider will be contacted for confirmation. For non-OHSU patients, we'll initially collect their cancer health history by a self-report questionnaire and confirm when we receive the survivor's outside medical record (through a signed Release of Information)
* Scheduled to receive radiation therapy for curative intent
* Confirmed by review of the EMR and subsequently recorded in Survivor Health History. In cases where the EMR isn't clear, their OHSU provider will be contacted for confirmation/ For non-OHSU patients, we'll initially collect their cancer health history by a self-report questionnaire and confirm when we receive the survivor's outside medical record (through a signed Release of Information)
• Completed surgery \>= 6 weeks prior to enrollment and no concurrent adjuvant therapy other than ADT for prostate cancer or hormone therapy for breast cancer
* Confirmed by self-report on the Health History Questionnaire (HHQ). If unknown, the participant's healthcare provider will be contacted for confirmation
* Co-residing with an intimate partner or spouse who is willing to participate
* Confirmed by self-report on the Demographic Questionnaire
* INTERVENTION (SURVIVORS AND PARTNERS) INCLUSION
* 18 years of age and older
* For survivors: confirmed by review of the date of birth as documented in the Electronic Medical Record (EMR) and subsequently recorded in Survivor Health History. For non-OHSU patients, we'll collect their age by self-report on the Survivor Health History
* For partners: confirmed by self-report on the Health History Questionnaire
* \< 2 structured strength training sessions for less than 30 minutes per week in the last month
* Confirmed by self-report on Health History Questionnaire
* Home internet sufficient for videoconferencing
* Confirmed by staff review of Internet Connectivity Screening Guide with the participants and outcome recorded in a CRF
* Signed informed consent
* Confirmed by completion of e-Consent in REDCap
* Willing to be randomized into either study arm and adhere to study protocol
* Confirmed verbally with the participant and response documented in the Participant Tracking database
* IMPLEMENTATION INCLUSION
* Be one of these key stakeholders: patient, spouse/partner, healthcare providers, or administrator
* Verbal informed consent following receipt of an Information Sheet
Exclusion Criteria:
* INTERVENTION (SURVIVORS AND PARTNERS) EXCLUSION
* Cognitive difficulties that preclude answering the survey questions, participating in the exercise classes or performance tests, or providing informed consent
* In the event of a suspected undeclared cognitive impairment, it will be confirmed by physician clearance or professional opinion of the Principal Investigator, Kerri Winters-Stone
* A medical condition, movement or neurological disorder, or medication use that contraindicates participation in moderate intensity exercise. Specific contraindications include the following: poorly controlled diabetes, recent cardiac event, neuromuscular disease, untreated orthostatic hypertension, recent surgery, acute hernia, acute rheumatoid arthritis, severe memory disorders, severe balance disorder, inability to ambulate without a walker or wheelchair, inability to stand for 3 minutes, severe hearing or vision problem
* Confirmed by a combination of reviewing the EMR, self-report on the Health History Questionnaire, Charlson Comorbidity Index questionnaire, and/or by physician clearance. If in the professional opinion of the Principal Investigator, Dr. Kerri Winters-Stone, contraindications other than those identified by the patient or physician are present, she may consider the participant ineligible. For Spouse/Partner: must answer 'No'; to American College of Sports Medicine pre-participation screening questions. If spouse/partner answers 'Yes'; to either question they may be required to obtain physician clearance prior to becoming eligible. Physician clearance may also be requested at the discretion of the principal investigator.
• Not fluent in English and therefore incapable of answer survey questions, following directions during exercise or performance testing, and providing informed consent in English
* Confirmed by staff interaction and/or the professional opinion of the Principal Investigators, Dr. Kerri Winters-Stone