The heart is a muscle, and just like any other muscle in your body, being inactive will make the heart weak. If you have CHF your heart is already weak, but being inactive with CHF will only make your heart even weaker. Your heart needs to be made stronger by performing light exercise and activities, so that it does not get so weak that it causes pulmonary edema. However, it is important that a physical therapist guide you through early activities and teaches you what you should and should not do. You should not start exercising on your own because you are at an increased risk of developing complications. Physical therapists can monitor your heart's reaction to exercises and adjust your exercises appropriately.