Normally, getting around by foot instead of in a taxi would be considered good exercise.

Break a sweat, physical education teachers implore. Take the stairs instead of the escalator, to get in some extra cardio. Run around outside, parents across the world instruct children glued to monitors. This would all be valuable advice if we weren't considering doing these things in Hong Kong's thick, smoggy air.

Every inhalation of stale sum-mer fumes makes me feel like I'm shortening my lifespan and increasing the chance of developing pain-ful illnesses before dying. All the benefits of exercise are erased. I don't have proof, but it sure feels that way.

The nagging feeling that it's hazardous to be outside was especially strong at the end of last month, when pollution levels reached a record high. The government warned that children shouldn't venture outdoors at all. It's disgusting and it seems there's nothing anyone can do about it except block it out of their mind.

This leads us to another problem: must the health-conscious pay for gym membership so they can get meaningful exercise? Apartments are often too small even for press-ups, not to mention bulky equipment. On days with higher-than-normal pollution levels, playing sports outside makes me feel extra short of breath. The Bonham Road running trail, although lined with a few trees, is still shrouded in smog. There's no escape.

A few joggers in urban areas have taken to wearing hi-tech face masks.

Hong Kong is a wonderful city filled with excitement and beauty. We also enjoy many liberties, but it's sad that we don't have the freedom to breathe without serious risk to our health.