Research links vigorous exercise with improved memory, mood and mental clarity. But a new study in Medicine & Science in Sports & Exercise reports that running in a polluted urban area could diminish the positive brain boost you would ordinarily get from a workout.
Why? Hard exercise makes for faster and deeper breathing, meaning you take in more air—and everything in it. This exposes your body (and brain) to more toxins. (Even on a clear day, breath control while training is crucial to success. Learn the right way to breathe while working out.)
In the City
Vehicles and industrial sources emit harmful particles and gases that can make your eyes and throat burn, your head ache, your chest tighten and your breathing labored. Long term, it increases your risk of heart and lung disease.
Manage your risk: "The positive benefits of running likely outweigh the risks," says Linsey Marr, Ph.D., an environmental engineering professor at Virginia Tech. Still, it's best to skip outdoor runs when the air-quality index is 100-plus. To reduce exposure on other days, run in the morning in parks or near water.
Wondering what workout gear to put on for your outdoor runs? Plug in the weather conditions in our What to Wear App to figure out.