Self-directed Use of Resources for Physical Activity (CHARGE)

To prepare for a future fully powered RCT, the investigators are conducting a pilot RCT. The pilot RCT will enroll n=39 insufficiently active primary care patients, and randomize them to one of 3 conditions: LLM alone condition: participants are recommended to use a publicly available, general-purpose LLM for physical activity promotion over the next 3 months (n=13); LLM enhanced condition: participants are recommended to use a publicly available, general-purpose LLM for physical activity promotion over the next 3 months and additionally attend an initial session providing guidance on LLM use and weekly text message with suggestions on using the LLM (n=13); or Control condition: participants are recommended to use publicly available tools to help with sleep (websites with tips for sleep and guided meditation videos) over the next 3 months (n=13). At study onset, all participants will be given basic information about exercise safety. At 3 months, moderate-to-vigorous physical activity will be measured with a validated self-report measure. Feasibility and acceptability outcomes such as recruitment and retention--metrics essential for advancing to a subsequent large-scale trial-will be measured.