 When you train at elite level, getting out of breath is par for the course. But studies suggest athletes like these can take in as much as 20 times more air than a person at rest, meaning they also breathe in 20 times more pollution. It's something that can impact even the very best, including two-time marathon Olympic champion Elliot Kipchoge. If you run in a polluted city, you really feel that your lungs are really compressed due to the pollution.