title: Effects of physical activity on exercise tests and respiratory function.
abstract: BACKGROUND
  Exercise is an important component of pulmonary rehabilitation for patients with chronic lung disease.
  
  
  OBJECTIVE
  To explore the role of physical activity in maintaining cardiac and respiratory function in healthy people.
  
  
  METHODS
  Cardiorespiratory fitness was measured by a maximal treadmill test (MTT), and respiratory function was tested by spirometry. The cross sectional study included data from 24 536 healthy persons who were examined at the Cooper Clinic between 1971 and 1995; the longitudinal study included data from 5707 healthy persons who had an initial visit between 1971 and 1995 and a subsequent visit during the next five years. All participants were aged 25-55 years and completed a cardiorespiratory test and a medical questionnaire.
  
  
  RESULTS
  In the cross sectional study, after controlling for covariates, being active and not being a recent smoker were associated with better cardiorespiratory fitness and respiratory function in both men and women. In the follow up study, persons who remained or became active had better MTT than persons who remained or became sedentary. Men who remained active had higher forced expiratory volume in one second (FEV(1)) and forced vital capacity (FVC) than the other groups. Smoking was related to lower cardiorespiratory fitness and respiratory function.
  
  
  CONCLUSIONS
  Physical activity and non-smoking or smoking cessation is associated with maintenance of cardiorespiratory fitness. Change in physical activity habits is associated with change in cardiorespiratory fitness, but respiratory function contributed little to this association during a five year follow up.
authors.affiliation: The Cooper Institute, Atlanta, GA, USA. ycc1@cdc.gov
authors.forename: Y J
authors.initials: YJ
authors.lastname: Cheng
authors.forename: C A
authors.initials: CA
authors.lastname: Macera
authors.forename: C L
authors.initials: CL
authors.lastname: Addy
authors.forename: F S
authors.initials: FS
authors.lastname: Sy
authors.forename: D
authors.initials: D
authors.lastname: Wieland
authors.forename: S N
authors.initials: SN
authors.lastname: Blair
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D012119:Respiration; D012907:Smoking / Q000009:adverse effects; D013147:Spirometry; D014797:Vital Capacity