The Influence of Cardiorespiratory Fitness on Firefighter Cardiovascular Health Under Exercise Conditions

On either Visit 3 or 4, subjects performed a maximal cardiopulmonary GEST following the Balke protocol. Immediately prior to the GEST, the study physician or his designee performed a brief physical examination, in which BP was assessed and all relevant medical information (i.e. medical history, medications, family history) were reviewed. The physician who completed the physical examination remained present during the GEST to monitor the subjects' electrocardiogram (ECG) and other physical signs. After the GEST was completed, the study physician reviewed the ECG for signs of ischemia. Breath-by-breath analysis of expired gases (i.e. oxygen and carbon dioxide) (ParvoMedicsTruneOne® 2400 Metabolic Measurement System, ParvoMedics Inc., Sandy, UT) determined maximal oxygen uptake (VO2max). Heart rate was measured continuously with a 12-lead ECG system and BP was measured by auscultation every 3 minutes during the GEST.