When kids sit and watch TV for hours on end, their breathing tends to become shallow, which may increase bronchial reactivity and airway irritation. This notion represents a startling reversal of past assumptions about obesity and asthma, two of the fastest growing, most pervasive public health problems in the United States. Incidence of asthma, which affects about 5.3 percent of adults and 6.3 percent of children, has more than doubled since 1980. The richer the country, the more obesity and asthma. But within the richer countries, it's the poorer people who have more asthma and obesity.
Experts offer many other theories to explain the poverty-asthma connection.
For example, the poor are more likely to live in run-down housing with allergens such as dust mites, cockroach droppings and mold. Physical activity helps relieve asthma in a variety of ways. When you're out of condition, you're less likely to get this broncho-dilating effect. Excessive weight on the chest can make it difficult to expand the lungs, notes Wenzel, who says exercise's potential for weight loss also can help people breathe easier. I've had a lot of patients with asthma report they've benefited from taking karate, which teaches breath control.