The advice usually given is that formulated by the American College of Sports Medicine (1976) - that anyone over the age of 35 should have a full medical examination, including an electrocardiogram recorded before, during and after maximal exercise. Persons under 35 who have risk factors for heart disease (a family history of heart disease, a history of smoking, high blood pressure or high blood fat levels) should also be tested. More recent guidelines from the U.S. National Heart Lung and Blood Institute (1981) say that you should consult a doctor before beginning an exercise program is you meet any of the following criteria: 1. You are over age 60 and not accustomed to vigorous exercise. 2. You have a family history of premature coronary heart disease (under 55 years of age). 3. You frequently have pains or pressure in the left or midchest area, left neck, shoulder or arm (distinct from the "stitch") during or immediately after exercise. 4. You often feel faint or have spells of severe dizziness, or you experience extreme breathlessness after mild exertion. 5. Your doctor has said that your blood pressure is too high, or you do not know that it is normal. 6. Your doctor has said that you have heart trouble, that you have a heart murmur, or that you have had a heart attack. 7. Your doctor has said that you have bone or joint problems, such as arthritis . 8. You have a medical condition that might need special attention in an exercise program. [the above taken from Noakes] Use your common sense. Go to your doctor if you are in doubt.

Definitely check with your doctor before starting any exercise regimen. You might also check in at Livestrong for more beginner workout ideas. Good luck getting fit!

Depends on how intense your exercise program is and how good your general health is. Age would matter too. Kinda like chicken soup, going and getting a medical exam couldn't hurt. A yearly physical wouldn't be a bad idea anyway.