Advancing Age and the Cardiorespiratory Stress of Fire Suppression: Determining a Minimum Standard for Aerobic Fitness

This study establishes and subsequently validates a minimum cutoff for the cardiovascular fitness of firefighters. Volunteers (n = 150) representing five discrete age classifications from 20 to 65 years were selected randomly for testing on their cardiovascular and pulmonary status. Discriminant function analysis was used to identify a group (n = 20) of firefighters to be monitored on heart rate (HR), oxygen consumption (vo,), and inspired ventilation (v,) during performance of a simulated fire-suppression protocol. Average VO, rnax of the subject group was 39.9 + 5.1 mlskg-lamin-1. They worked at 76 + 8% of VO, rnax with a V, of 46.7 + 3.4 lomin-1. The HR attained was 173 + 9 beatdmin. Based on these data a minimum VO, rnax of 33.5 ml. kg-1-min-1 was proposed as appropriate in order to maintain performance effectiveness. Concurrent validity of the proposed cutoff was examined in 32 additional firefighters. Individuals with VO, max values between 33.5-5 1.0 ml kg- I. min- had a significantly higher probability of successfully completing a fire-suppression protocol than firefighters with a VO, rnax between 26.0-33.49 ml.kgl.min -1.