This is the VOA Special English Health Report.

Watching the Olympics probably made some people feel a little guilty about not exercising. The truth is, if physical inactivity were a sport, a lot of us could give a gold-medal performance. Or should we say non-performance?

To mark the London Olympics, the Lancet, a British medical journal, published a series of papers about this problem. Public health experts say physical inactivity is the world's fourth leading cause of death. They estimate that inactivity plays a major part in six to ten percent of deaths from non-communicable diseases. These include conditions like heart disease, diabetes, and colon and breast cancer.

I. Min Lee at the Harvard School of Public Health worked with a team that studied inactivity. She says the findings are conservative and may even underestimate the problem.

I. MIN LEE: "Physical inactivity is harmful to health, as harmful as far as deaths are concerned as smoking."

The researchers compared data on physical inactivity with disease rates in 122 countries.

I. MIN LEE: "So when we did our analysis, we looked at increased risk of disease after taking into account other health habits that might be associated with physical activity. For example, we know that if you are active, you probably smoke less. Additionally we factored out obesity, independent of the fact that active people also tend to weigh less."

Harold Kohl from the University of Texas School of Public Health also worked on the special report. He says physical inactivity should be recognized as a global epidemic.

HAROLD KOHL: "We have to realize that high income countries are the most inactive around the world, but low to middle income countries are not going to be far behind as things change, as their economies improve and their people rely more on the improvements that basically engineer physical activity out of our daily lives."

Harold Kohl points to campaigns that continue to reduce smoking and alcohol use. He says the time has come to target physical inactivity as a major threat to public health.

HAROLD KOHL: "It is not just telling someone to go out and be physically active, but how we rely on the transportation sector or how our cities or neighborhoods are designed, how crime can be minimized to help people become more physically active in their neighborhoods, simply walking to the store or walking down and being outside with friends and family and so forth. These broader environmental issues are becoming much clearer in terms of their effects."

I. Min Lee agrees -- and she challenges people to do 150 minutes a week of moderately intense exercise.

I. MIN LEE: "Anything you can do is great! Even if you don't reach that 150 minutes a week, a little is better than none and more is better than a little."

She plans to return every four years -- just like the Olympics -- (to give a progress report) to tell us how the world is doing.

And that's the VOA Special English Health Report. How much physical activity do you get? Are you a couch potato or a gym rat, someone who just sits and watches TV or someone who continually works out at the gym? Tell us at voaspecialenglish.com. And if you listen to music when you exercise, give us your nominations for the best workout songs. I'm Lorry Berman.

colon: 結(jié)腸

engineer: 建造或操縱

gym rat: 健身迷

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（來源：VOA 編輯：實習生朱眉霖）