The Lung and the Restless

An expert explains why L.A.’s air quality shouldn’t spoil your workout

Illustration by Jason Schneider

The city’s air isn’t as smoggy as it was in the ’70s, but it’s still hard on the body. High temperatures cook contaminants in the air and raise the level of ozone, a lung irritant that has been linked to asthma and heart disease. Ed Avol, an air quality expert at USC’s Keck School of Medicine, advocates a “when and where” approach to exercising outside.

Unless you’re exercising by the ports, the coast is your best bet. “The air over the water is cleaner, and it typically blows west to east,” says Avol.

Rainy and overcast days are also easy on the lungs. The electrostatic activity and the turbulence help clean the air.

Ozone levels tend to be highest in the afternoon, when temperatures peak. Stick to early-morning and late-evening outings to dodge the heat and belching tailpipes.

Exercising roadside isn’t an ideal option because of car exhaust and tiny airborne particles from tires. If you can’t avoid the boulevards, at least steer clear during rush hour.