Time to Move in Pregnancy Hyperglycemia

Research participants will: 1. Exercise according to a schedule provided by the study for an 11-day period. They will complete either no exercise or 30 minutes of walking/stepping (e.g., stepping in place or around the house when walking outside is not an option or not an attractive option) on specifically assigned days, at specifically assigned times of day. 2. Wear a masked Dexcom G6 continuous glucose monitor (CGM) or unmasked Dexcom G7 CGM for the 11-day study period. 3. Wear a masked physical activity (PA) monitor watch (ActiGraph CentrePoint Insight Watch) on the non-dominant wrist for the 11-day study period (all day and all night). 4. Take pictures of all of food and drinks consumed, at the start and end (showing food and drink not eaten) of all eating occasions. Participants will use their phones to upload photos to a study website for the entire 11-day study period. Participants will also complete 24-hour dietary recall phone calls for 3 of the 11 study days (i.e., for 1 morning PA day, 1 late afternoon/evening PA day, and 1 no PA day, with the days randomly selected). 5. Complete electronic REDCap surveys, including daily surveys that assess: when (i.e., the exact times) they started eating breakfast, lunch, and dinner that day; when (e.g., the exact times) they went to bed and fell asleep for the night and woke up and got out of bed the next morning, and questions on the quality of their sleep; adverse events and issues with the study equipment (e.g., CGM); and mood state following PA (on days assigned 30 minutes of walking/stepping).