If you’re having trouble catching your breath during your workout, it may not be the exercise that’s making your lungs work overtime – it may be the air you’re breathing.

The Mother Nature Network posted this article on a study undertaken to look at indoor air quality at gyms:

[M]onitors showed high levels of airborne dust, formaldehyde and carbon dioxide in concentrations that exceeded most accepted standards for indoor air quality. The levels were especially high during evening exercise classes, when many people were packed into small rooms, stirring up dust and fumes and puffing out large doses of carbon dioxide with every breath. The high concentrations of dust and formaldehyde were the biggest concern, because consistent exposure to these chemicals has been linked to asthma and other respiratory issues.

Over at RIDE Solutions, I advocate integrating exercise into your commute through biking and walking (even if it’s biking at walking to the bus stop) as a way to enjoy the outdoors, but the article points out that during the colder and darker winter months people are includes to take their exercise indoors.  While the article doesn’t suggest cancelling your gym membership, it does suggest avoiding the busiest times to avoid the worst air quality issues.