Hi, CO2 and work-out Captain here. I don't know how much CO2 you typically exhale when you do push ups but it is nothing near the exhaust fumes by your 5lt gasoline SUV built in 1990.
It’s especially funny as you would think the whole reason people want to live so close to other people is because they don’t want to travel far to engage with other people… Yet it is always about how to get as far away from them as possible, whether by bike or train or whatever it takes.