Optimizing a Remote-based Physical Activity Intervention for Adults With Total Knee Replacement

All participants will receive a 6-month, fully automated online behavioral exercise program (Energize! Exercise Program). This program is designed to increase moderate-intensity physical activity among individuals who engage in little to no physical activity at baseline. Over the course of the program, participants are given a physical activity goal which starts at 75 minutes per week and gradually progresses to 200 minutes per week. Participants are instructed to view a 10-15-minute video lesson weekly, during months 1-3, and monthly during months 4-6. These lessons teach behavioral principles for increasing exercise and maintaining physical activity long-term. Participants are also asked to complete an 'Apply Your Knowledge' activity after watching each video lesson. These activities are designed to help the participant engage more with the lesson content, with a particular emphasis on applying the content to their lives. Within this program, participants are also asked to plan and report their exercise each week, and automated feedback is provided based upon their weekly physical activity reports.

In addition to receiving the Energize! Exercise Program, participants will be randomly assigned to receive 0-4 supplemental intervention components (phone coaching, progress reports to providers, 'Hear From Others' videos, and individualized feedback) which are each described in more detail below.

Inclusion criteria

• had a knee replacement (including primary, staged or independent bilateral, or revision) at least 12 months ago
• have a computer, tablet, or smartphone with active internet access
• self-report engaging in less than 60 minutes/week of moderate-intensity physical activity
• be English-speaking and able to read consent and study materials written in English
• be willing to complete the 4 remote assessments, including physical activity monitoring
• be willing to be randomized to receive 0-4 supplemental intervention components.

Exclusion criteria

• any contraindications to physical activity (e.g., chest pain)
• have a scheduled surgery within the next 12 months (e.g., hip or knee replacement)
• have a mobility limiting comorbidity unrelated to knee replacement
• live outside of the continental U.S
• do not currently have a physician or orthopedic surgeon whom they see regularly
• are currently participating in physical therapy (for knee)
• are participating in a structured weight loss or physical activity program
• unable to provide proof of knee replacement surgery
• have a BMI >40kg/m2
• score >30 on PROMIS cognitive function