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 one hundred fifty 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.