If you live in a city, there are risks to going for an afternoon walk when the sun is shining and the temperatures are climbing. Exercise, pollution and heat don’t mix. Smog hangs in the air during the summertime, causing health effects ranging from a dry cough and worsened asthma symptoms to reduced lung function. Regular exposure to smog has even been linked to lung cancer. That does not mean you have to be stuck inside when the weather is hot. 

Follow these tips to reduce your exposure to smog.

Check the time: “You can minimize your exposure to pollutants by choosing the right time of day to go for a walk,” says Kenneth Rundell, PhD, director of respiratory research and the human physiology lab at Marywood University in Scranton, Pa. Exercising very early in the morning (even before sunrise) or after sunset will minimize exposure to air pollution. Exercise at the start or end of your day rather than around lunch or dinner time.

Plan your route: Avoid busy streets. Instead, walk in low-traffic neighborhoods, ride your bike along the waterfront or go to the park to exercise. “Pollution levels drop dramatically if you move even 100 meters away from heavily-trafficked areas,” says Rundell.

Eat right: Antioxidants like vitamins C, E and beta-carotene and the mineral selenium can protect your lungs from irritants, including those found in smog, according to researchers at Cornell University. Eat lots of fruits and veggies and consider taking a daily multivitamin.

Monitor pollution levels: Local TV and radio stations broadcast air quality updates, using the Air Quality Index or Pollutant Standards Index. If the index rises above 200, the air is considered “very unhealthful” according to federal standards. On those days, you may better off going to the gym or walking around the mall.