Dusting will give you a little bit of exercise, of course, but that's not the point. It's to remove chemicals that mess with your body. According to this study, two-thirds of the chemicals researchers suspected and tested increased the growth of fat cells.
These chemicals are often referred to as endocrine-disrupters, human-made chemicals that your body thinks are hormones. Hormones regulate a lot more than women's periods. They regulate a lot of your body's functions including metabolism. These endocrine-disrupters like to hang out in fat cells, so they concentrate there. And what's really scary is this concentrates them in breast milk. They also end up in household dust.
Where do they come from? Does your shampoo have parabens? Has your sofa been treated with fire retardants? Do you use a plastic water bottle or heat up food in plastic storage containers?
So mop with a damp mop and dust with a damp rag (so you don't just move the dust back into the air.) Check the ingredients in your personal care products. Avoid products with "fragrance" like laundry soap. Store and heat your left-overs in glass.
Chemicals lurking in household dust may prime cells to store fat - Popular Science