Most people can begin a program of moderate exercise, such as regular walking and building strength using body weight for resistance. Anyone with arthritis, diabetes, heart disease, liver disease, kidney disease, lung disease or asthma should bring up the subject at a regular physician's appointment before taking on such activities.

If you experience muscle pain, uncomfortable shortness of breath, dizziness, or chest pain or tightness while you are exercising, consult your doctor before continuing.

The American College of Sports Medicine suggests you have a complete physical examination before starting a program of vigorous exercise, especially if any of the following descriptions apply to you:

• You're a man older than age 45 or a woman older than age 55


• You have a family history of heart disease before age 55


• You smoke or you quit smoking in the past six months


• You haven't exercised for three months or more


• You're overweight or obese


• You have high blood pressure or high cholesterol


• You have impaired glucose tolerance, also called prediabetes