Body Composition Is Related to Maximal Effort Treadmill Test Time in Firefighters.

Firefighting tasks may require near maximal levels of cardiorespiratory fitness. Previous research has indicated that body fat percentage (BF%) and aerobic capacity (VO 2peak ) are related to the performance of firefighting tasks. Since a standard submaximal treadmill test for firefighters is terminated at 85% of maximal heart rate (MHR), key performance information relating to maximal cardiorespiratory effort may not be measured in a submaximal test. The purpose of this study was to examine the relationships between body composition and time spent running at intensities greater that 85% MHR. Height, weight, body mass index (BMI; kg/m 2 ), BF%, MHR (bpm), VO 2peak (mL/kg/min), predicted VO 2peak (P-VO 2peak ; mL/kg/min), submaximal treadmill test time (WFI sub Test Time; min), and maximal treadmill test time (WFI max Test Time; min) were collected in fifteen active-duty firefighters. The results indicated that significant relationships ( p < 0.05) existed between BF% and VO 2peak , BF% and WFI max Test Time, BF% and T diff , and VO 2peak and WFI max Test Time. P-VO 2peak was not significantly different than VO 2peak , and the WFI max Test Time was significantly longer than the WFI sub Test Time. These results indicate that a submaximal treadmill test may reasonably predict VO 2peak , but key information about physiological work at intensities greater than 85% MHR may be missed when using submaximal effort tests.