Validation Of A Field-Based Aerobic Capacity Assessment In Firefighters

Cardiovascular disease (CVD) is the leading cause of on-duty death and morbidity in firefighters. Aerobic capacity (VO2 max) has been shown to be a significant predictor of CVD events in firefighters. The Fire Service Joint Labor Management Wellness Fitness Initiative (WFI) currently uses a submaximal treadmill test to estimate the aerobic capacity of firefighters. This submaximal field-based protocol has yet to be validated with an accepted laboratory-based test. PURPOSE: The purpose of this study is to evaluate the validity of this submaximal treadmill test in predicting the true VO2 max of firefighters. METHODS: Thirteen firefighters from North Central Florida completed the WFI submaximal treadmill test and were subsequently evaluated using the Bruce maximal protocol to determine their true aerobic capacity. RESULTS: The mean predicted and observed VO2 max values are similar (45.0± 4.5 and 44.5 ±8.4 ml/kg/min respectively). However, the Standard Error of the Estimate shows that the field-based submaximal VO2 test inaccurately predicts true VO2 max by an average of 4.62 ml/kg/min. The submaximal test over-predicted the observed VO2 max in 54% of subjects, and under predicted in 14% of subjects. The margin of error in prediction was greater than 10% in either direction. CONCLUSION: Accurate and reliable assessment of aerobic capacity has important implications in reducing rates of on-duty deaths and disease from CVD in firefighters. These results indicate that a more robust and precise field-based aerobic capacity assessment may be needed to predict the true VO2 max of firefighters.