Exercising in polluted air can actually backfire, says WHO

Technology Dec 04, 2025

Thinking of going for a run outside?
The World Health Organization (WHO) warns that working out in polluted air—especially with stuff like PM2.5, ozone, and nitrogen dioxide—means you end up breathing these particles in even deeper.
Instead of boosting your health, this can cause inflammation and stress in your body, making it harder to see real fitness gains or improve your performance.

Why it matters: Long-term effects add up

Over time, exercising regularly in dirty air can reduce the usual benefits you'd expect—like better endurance, stronger lungs, and improved metabolism.
It also makes workouts tougher for anyone with asthma or breathing issues.
Basically, if the air's bad outside, you might want to rethink that outdoor workout.