This study will see if patient who undergo a physical activity intervention called Walk With Ease report experiencing less fatigue and a higher quality of life during chemotherapy for colorectal cancer than those who do not participate in this intervention.

The primary purpose of this multicenter, randomized controlled study is to evaluate the impact of a physical activity program on fatigue in older patients (≥60 years) undergoing adjuvant chemotherapy for colorectal cancer. The investigators also plan to evaluate physical function and quality of life as secondary objectives. The investigators' hypotheses are that people who undergo the physical activity intervention compared to those who do not, will: 1) report less fatigue, 2) report higher health related quality of life, and 3) have less decline in physical function. Additionally, The investigators will characterize ≥grade 3 adjuvant chemotherapy associated toxicities in this older population, and describe the changes reported in fatigue, physical function, and HRQOL over the course of chemotherapy.

Inclusion Criteria:

• ≥ Age 60 years (no upper age limit)
• Diagnosis of stage II-III colon or rectal cancer planned for treatment with adjuvant chemotherapy scheduled as part of standard treatment
• Able to read English (required for CGA and other surveys administered)
• Approval from their treating physician to engage in moderate-intensity physical activity
• Patient-assessed ability to walk and engage in moderate physical activity
• Signed, IRB-approved written informed consent

Exclusion Criteria:

• Other active, invasive malignancy requiring ongoing therapy or expected to require systemic therapy
• Already walking or engaging in other physical activity >120 minutes per week as documented via subject self-report
• Unable to walk or engage in moderate-intensity physical activity
• One or more significant medical conditions that in the physician's judgment preclude participation in the walking intervention