SORRY, you've been lied to. Forty is not the new 30, and there is no surgery, cream, magic elixir, age-proofing diet or fountain of youth. Exercise, I'm afraid, is not a cure-all.

In our youth-obsessed culture, we resist the inevitability of change. Even worse, we want guarantees that if we eat the "right diet" and do the "right exercises" we will not only bypass aging and avoid diseases, we will ultimately cheat death itself.

A few weeks ago I overheard a conversation between two women who were grappling with the sudden death of a dear friend. According to them, the deceased was beautiful, stunningly fit and looked at least 10 years younger than her true age.

While listening to the conversation, it became fairly obvious to me that on some level these women mistakenly thought that beauty or fitness guaranteed good health and prevented death.

Undeniably, exercise offers myriad benefits, including reducing the risks of heart disease and some cancers, improving blood sugar, staving off osteoporosis, boosting energy levels and improving mood.

But exercise is no panacea for all that ails us. No level of exercise can guarantee good health. Exercise, like vitamins, should be viewed as an ounce of prevention and not a cure-all.

With that said, forget about the myths and the slogans, but do note these five important points:

Exercise, yes, but keep up preventive care. Exercise is a complement to, not a replacement for, preventive care. Preventive care requires that you maintain a working relationship with your primary-care doctor. Find out from your primary doctor which screening tests and immunizations you need and when they are due. Maintain a tickler file and write the dates down in a personal planner. Then be sure to schedule those appointments and get it done. For example, at age 50 it is recommended that all adults get their first colonoscopy - earlier if there is a family history of colon cancer.

Keep a family history. Before you schedule your doctor appointment, know as much as you can about your personal health and family health history. Are you allergic to latex? Did you have the mumps and measles when you were a child? Did Mom have high blood pressure and Dad have diabetes? Ask questions and gather as much data on your family health history as you can. Identifying personal and family risk factors is key to health maintenance and prevention strategies.

Myth: Muscular, strong and beautiful bodies are proof of good health. While most exercise enthusiasts would like to believe this, it's simply not true. Like it or not, there are plenty of people who look amazingly healthy and fit, but have some deadly disease. While I encourage all to exercise regularly, real health goes far beyond a six-pack.

Beware the Scrooge of health. A sedentary lifestyle is the biggest Scrooge to good health. Daily exercise is beneficial to all, young and old. Regular exercise may reduce your risks to many chronic diseases, and also help you avoid being flabby, weak and tired. Regular physical exercise is a must.

The only competition is you. Remember to exercise at your own pace, and compete only with yourself. Follow common sense, listen to your own body and avoid comparing. Some people foolishly injure themselves - or worse - trying to keep up with others. Don't let your ego get you hurt.