Wwnt for acheckup at work occupational health nurse non smoker 5ft 8 go to gym 4 days a week got spirometery test done im 53 yrs old 5ft 8 tall was told my lung age is 78 years im pretty fit or at least i thought i was can do 30 minutes on a crosstrainer ata high level was a bit worried to be told this ive tried my sons peak flow meter who has asthma and i can only blow it to 550.what u think