Start slow and take into account your overall health. Build up an exercise plan that works for you and keeps you motivated. You should aim for a goal of at least 30 minutes of aerobic exercise most days of the week. If you think that you can’t find 30 minutes, you can break up the exercise into chunks—10 minutes throughout the day. Once you are able to reach your goal of 30 minutes of aerobic activity, you can then add strength training to build muscle mass. Lifting weights for 20-30 minutes two or three times a week is sufficient to get the full benefits of strength training.