Validation of a Cardiorespiratory Fitness Assessment for Firefighters

Abstract

Currently, a submaximal protocol is used to measure cardiorespiratory fitness in firefighters by estimating their true aerobic capacity (V[Combining Dot Above]O2max); however, this submaximal test has not been cross-validated among firefighters. Thirty firefighters (85% male, 15% female), completed the submaximal protocol and the maximal (Bruce) treadmill protocol on separate occasions. Pearson's correlation analyses between the submaximal and Bruce protocol revealed a significant moderate positive correlation (r = 0.635, p = 0.005). The range of mean V[Combining Dot Above]O2max values and SDs produced from the submaximal and maximal protocols varied greatly (35.4-50.9 vs. 28.6-58.4 ml·kg·min, and SD of 3.91 vs. 7.22, respectively). The submaximal V[Combining Dot Above]O2 test underestimated the true V[Combining Dot Above]O2max in the majority of firefighters (72.4%) and overestimated the true V[Combining Dot Above]O2max in the remainder of firefighters. Participants with a higher body fat percentage were more likely (p = 0.0157) to have an overestimated true V[Combining Dot Above]O2max than those with a lower-body fat percentage. Our results indicate the current submaximal V[Combining Dot Above]O2 test used to measure cardiorespiratory fitness in firefighters is an improvement over previous protocols. However, our findings also show that the accuracy of this submaximal test for predicting the true V[Combining Dot Above]O2max in firefighters is questionable, and may not identify firefighters who possess substandard cardiorespiratory fitness, particularly in those with a higher percentage of body fat. Thus, the results of this study indicate that improvements to the current Fire Service Joint Management, Wellness & Fitness Initiative (WFI) V[Combining Dot Above]O2 assessment is still needed to accurately reflect the true V[Combining Dot Above]O2max of individual firefighters.

Body Composition and Fitness Characteristics of Firefighters Participating in a Health and Wellness Program: Relationships and Descriptive Data

“…The Bruce Protocol is a 7-stage graded exercise treadmill test that measures the ability to perform moderately strenuous exercise over an extended time and is used to estimate maximal aerobic capacity [ 62 ]. This protocol has been used within the health and wellness program for many years to produce historical normative data and has also been adopted before for aerobic testing in firefighters [ 63 , 64 , 65 , 66 ]. Standard procedures were followed for this test [ 62 , 63 , 64 , 65 , 66 ].…”

“…This protocol has been used within the health and wellness program for many years to produce historical normative data and has also been adopted before for aerobic testing in firefighters [ 63 , 64 , 65 , 66 ]. Standard procedures were followed for this test [ 62 , 63 , 64 , 65 , 66 ]. Following a 1 min warm-up on the treadmill at a speed of 2.7 km per hour (km/h) with a 0% grade, the Bruce Protocol was initiated, prompting firefighters to begin stage 1 at a speed of 2.7 km/h with a 10% grade.…”

Isokinetic Strength, Vertical Jump Performance, and Strength Differences in First Line Professional Firefighters Competing in Fire Sport

“…Although presented study aimed on determination of isokinetic and explosive strength, cardiorespiratory fitness is also an important component of good health-related physical fitness. A low level of cardiovascular fitness is associated with risk factors of cardiovascular diseases [43], such as hypertension, dyslipidaemia, and obesity, which are leading cause of on-duty death or disability [44] in firefighters. Obesity is associated with a sedentary job and lack of movement, irregular sleeping, unbalanced and irregular nutrition, and effect of 24 h shifts as factors threatening first-line firefighters [45].…”

Firefighter Health: A Narrative Review of Occupational Threats and Countermeasures

“…Interestingly, Dolezal et al concluded that the WFI protocol had a tendency to overestimate CRF among those who were considered less fit while underestimating those who were considered high fit (i.e., 11% error margin) [56]. Moreover, it was noted that the present policies for measuring CRF among firefighters should be reevaluated, and a more robust approach is likely needed [54,57]. Fire departments are beginning to utilize alternative field-based protocols to assess CRF among firefighters, including maximal effort intermittent shuttle run tests (e.g., 30-15 intermittent fitness test (IFT)), which may simulate the discontinuous physical efforts frequently utilized on the fireground, or continuous shuttle run (beep) tests; both of which allow for multiple firefighters to be tested concurrently.…”

“…The most accurate way to assess CRF is to measure oxygen consumption with a gas analyzer during a maximal effort on a treadmill or cycle ergometer. CRF assessments might not always be feasible due to expense, time, and requirements for proper exercise testing equipment [56][57][58]. Interestingly, Yang et al conducted a retrospective longitudinal cohort study among 1104 firefighters from 10 fire departments over a 10-year period [59].…”