To learn if an 8-week, phone-based texting intervention program will reduce sedentary (non-mobile) behavior.

Primary Objective: To test the effect of two text messaging strategies, responsive texts and standard scheduled texts, on sedentary behavior in a racially and geographically diverse sample of adults.

Secondary Objective: To assess participant engagement with the program and with the educational content delivered via text messaging.

Exploratory Objective: To determine whether two text messaging strategies, responsive texts and standard scheduled texts, increases physical activity in a racially and geographically diverse sample of adults.

Exploratory Objective: To determine whether two text messaging strategies, responsive texts and standard scheduled texts are associated with changes in corresponding patient attitudes as assessed by surveys of exploring sedentary behavior, readiness for exercise change, and physical functioning.

Inclusion criteria:

1. >18 years old
2. owns a smart phone
3. has access to WiFi or willing to use mobile data
4. has an email address or willing to create an email address
5. able to read and understand English;
6. able to give informed consent;
7. willing to receive text messages and complete brief questionnaires on their smart phone
8. self-reports sedentary behavior (> 6 hours/day of sitting time).

Exclusion criteria:

1. unwilling to have sedentary behavior and activity tracked
2. unable to walk without ambulatory assistance device (i.e. cane or walker) or due to underlying medical condition
3. MD Anderson employees that report to the Principal Investigators of this study
4. family or household member already enrolled into study
5. not sedentary based on < 6 hours/day of sitting time, and (6) currently participating in a weight management or exercise study or program