In fact, in the summer of 2012, the CDC reported that more Americans were walking for exercise, with those who walk being nearly 3 times more likely to meet the recommended level of physical activity.

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Rather than the exclusive focus on BMI and weight loss, focusing on maintaining an adequate level of physical activity throughout life is likely to be the most effective way to counter the deposition of abdominal fat and the adverse metabolic changes that accompany it.

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Physical activity levels were much higher among children, where the recommended level is 60 minutes each day, including school-based activity.

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If you were outdoors in air quality of that level, you'd be told to go indoors and not do any physical activity.

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