Is there any study that explores whether people in big cities physically exert themselves more as part of their daily routine to the benefit of their physical health?

My thinking is this: people living in big cities (e.g. London, New York) often do not own a car and rely on public transport to commute to work 5 days a week. This might involve walking from their home to a subway station (and maybe climbing some stairs) as well as walking several blocks to their office when alighting from the subway. This is physically strenuous and something that those taking a car do not have to endure (I speak from experience, going to college in London but now being spoilt by the suburban California lifestyle).

In practice I know that there are many variables that cloud this argument so I wanted to know if there is any systematic research about it.