An Exercise and Nutrition Monitoring Intervention (Pt Pal) for the Improvement of Strength in Patients With Pancreatic or Stomach Cancer Receiving Chemoradiation Therapy Before Surgery, SurgeryStrong Study

Inclusion Criteria: * Pancreatic or gastric adenocarcinoma, biopsy-proven * Have completed or are within 2 weeks of completion of preoperative chemoradiotherapy either on- or off-protocol * Anticipated to undergo potentially curative resection in 4-6 weeks from enrollment * Able to understand the description of the study and willing to participate * Able to understand the exercise program * Able to independently maintain daily exercise logs via Pt Pal -iOS, Android or desktop web browser on their own personal device * Telephone or email access and agreement to engage with the research personnel via phone or email * Meet all screening requirements, including physician clearance * \>= age 18 Exclusion Criteria: * Non-English speaking * Has participated in moderate to high intensity strengthening exercises at least two times per week within the past four weeks prior to enrollment * Unable to complete the baseline assessment questionnaires or functional assessments * Underlying unstable cardiac or pulmonary disease or symptomatic cardiac disease (New York Heart Association functional class III or IV) * Recent fracture or acute musculoskeletal injury that precludes the ability to weight bear fully on all 4 limbs in order to participate in an exercise intervention * Numeric pain rating scale of \>= 7 out of 10 * Myopathic or rheumatologic disease that impacts physical function * Recurrent cancer following prior resection * \< age 18