Physical Activity In Gastrointestinal Cancer

Inclusion Criteria: * Start of trial: * A three-month of strict inclusion criteria (Phase 1). * At the end of three-months, if at least six participants have not been accrued, inclusion criteria will be expanded for a second three-month recruitment phase (Phase 2). * At the end of six-months, an average of two patients per month has not been accrued, a further expand inclusion criteria (Phase 3). * Phase 1 (most strict) Eligibility criteria include: * Voluntary, signed informed consent; * Diagnosis of histologically-confirmed esophageal, gastric, pancreatic, or colorectal that is metastatic or locally-advanced (unresectable); * First-line cytotoxic chemotherapy started within four-weeks of enrollment (patients can have reviewed prior adjuvant therapy if completed ≥6 months prior to start of first line chemotherapy for metastatic disease); * Age greater than 65 years; * Baseline weight-bearing physical activity less than 150 min∙wk-1 using the Paffenbarger physical activity questionnaire; * Eastern Cooperative Group Performance Status of 0, 1, or 2; * Self-reported ability to walk 400-meters (approximately one city block) without sitting, leaning, or the help of another person or walker; * Written physician approval; * Life expectancy \>3 months; * English speaking. * Phase 2 (less restrictive) Eligibility criteria will loosen: \-- The minimum age from greater than 65, to greater than 55; * Phase 3 (least restrictive) Eligibility criteria will add: \-- The minimum age from greater than 55, to greater than 18. * Exclusion Criteria * Known or suspected brain or other central nervous system metastases; * Uncontrolled cardiac or pulmonary disease; * Pregnant or breast feeding; * Any other condition that may impede testing of the study hypothesis, make it unsafe to engage in the physical activity program, or make the participant not available for end of study assessments (determined by the investigative team).