Participants in this group will receive a 12-week, social cognitive theory-based intervention targetting reduction of daily sedentary time. This information will be delivered to them in the form of Zoom workshops, a program workbook, personalized step count goals, and a private social media page. The aim of this component will be to have participants displace their daily sedentary time with light-intensity physical activity, such as casual walking. The second component of this intervention will be increasing participants' weekly MVPA engagement. Participants will participate in 1 live, virtual aerobics-based exercise class per week and complete 2 additional sessions on their own time. Participants will build up to exercising 150 minutes/week (the federal physical activity recommendations).

Participants in this group will only receive the MVPA-promoting component (which will be the same delivery as the intervention group). Participants in this arm will participate in 1 live, virtual aerobics-based exercise class per week (held separately from the intervention group) and will complete 2 additional exercise classes on their own time. Participants will build up to exercising 150 minutes/week (the federal physical activity recommendations).

12 week home-based exercise program to promote engagement of 150 min/week of moderate-vigorous intensity exercise; personalized step count goals to increase daily volume of physical activity and displacement of sedentary time

Participants will wear a hip-based pedometer for 7 days at baseline and 12 weeks

Participants will wear a hip-based accelerometer for 7 days at baseline and 12 weeks to measure their daily time spent sedentary.

Participants will wear a hip-based accelerometer for 7 days at baseline and 12 weeks to measure their daily time spent engaged in light-intensity physical activity.

Participants will wear a hip-based accelerometer for 7 days at baseline and 12 weeks to measure their daily time spent engaged in moderate-vigorous intensity physical activity.