Because someone who doesn't have a lung dysfunction doesn't need to.
Problem is these things aren't clear cut. A diagnosis that is.
Nothing to do with the human body is. That's why medicine uses things like probability and risk calculations to decide on a course of action for an illness.
@GoatandTricycle started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Because someone who doesn't have a lung dysfunction doesn't need to.