Lung age

It certainly worked fro some of my classmates in medical school.

I was an older (45 YO) student, and in physiology we had a lab where we performed lung function tests on each other.

A couple of my classmates were typical jocks – but smokers. I’ve never smoked. My lung function tests were what theirs should have been, and their results would have been bad for someone my age.

It helped motivate one of them to quit…..The others, well: Admission to medical school is no guarantee of native intelligence.