Epidemiologic data consistently indicate that colorectal cancer survivors can improve their quality-of-life and prognosis by engaging in physical activity. This study aims to build on this epidemiologic work and translate the findings to inform and change patient behavior. The specific aims are to: (1) Develop a mobile technology physical activity intervention among colorectal cancer patients who have completed therapy. (2) Conduct a 3-month pilot randomized controlled trial utilizing mobile technology to increase physical activity among 40 men and women who have completed standard cytotoxic chemotherapy for primary stage I-III colorectal cancer at the UCSF Helen Diller Family Comprehensive Cancer Center. Participants in the intervention arm will receive a Fitbit® for self-monitoring, interactive text messages, and educational print materials; participants in the control arm will receive educational print materials at baseline and will be given a Fitbit® after completion of the 3-mo. follow-up assessment.

Inclusion Criteria:

• stage I-III colon or rectal adenocarcinoma
• completed standard cytotoxic chemotherapy if medically indicated
• be considered disease-free at baseline
• be able to speak and read English
• have no contra-indication to moderate to vigorous aerobic exercise
• be able to walk unassisted
• be inactive at baseline (<150 min/week of moderate physical activity)
• have access to a mobile phone
• be able to navigate websites, fill out forms on the web, communicate by email, and have regular access to the internet