Performing one or more verification VO2 workload(s) immediately after an incremental to maximal graded exercise test significantly increases the proportion of participants who meet the job-related aerobic fitness standard for structural firefighters.

ABSTRACT

PURPOSE: Graded exercise tests (GXTs) are commonly used to determine the maximal oxygen consumption (VO2max) of firefighter applicants. However, the criteria used to confirm VO2max are inconsistent and have a high inter-subject variability, which can compromise the reliability of the results. To address this, a verification phase (VP) after the GXT has been proposed as a "gold standard" protocol for measuring VO2max. METHODS: 4179 male and 283 female firefighter applicants completed a GXT and a VP to measure their VO2max. VO2peak values measured during the GXT were compared to the VO2 values measured during the VP. The proportion of participants who met the job-related aerobic fitness standard during the GXT was compared to that of those who met the required standard during the VP. RESULTS: For male and female participants that required the VP to attain their VO2max, the VO2peak values measured during the GXT (47.3 ± 6.0 and 41.6 ± 5.3 mL kg-1 min-1) were, respectively, 10.1% and 10.3% lower than the VO2 values measured during the VP (52.1 ± 6.7 and 45.9 ± 6.4 mL kg-1 min-1), p < 0.001. Furthermore, the proportion of male and female participants who met the job-related aerobic fitness standard significantly increased from the GXT to the VP by 11.6% and 29.9%, respectively, p < 0.001. CONCLUSION: These results strongly support the use of a VP to confirm VO2max, especially for females, older and overweight individuals. These findings are applicable to other physically demanding public safety occupations and when examining the efficacy of training interventions on VO2max.