Validation of a bench stepping test for cardiorespiratory fitness classification of emergency service personnel.

Field tests are used in many occupations to screen and classify personnel for cardiorespiratory fitness. Presumably these tests yield predictive results which correlate well with maximal oxygen uptake (VO2 max), the most widely-accepted criterion of cardiorespiratory fitness. The purpose of this study was to validate one of the most popular field tests, the modified Kasch Pulse Recovery Step Test (KPRST), used by several emergency service agencies in Southern California. One hundred fourteen male state traffic officers from the California Highway Patrol, ranging in age from 24 to 56 years, performed treadmill VO2 max tests to volitional fatigue and the modified KPRST. Heart rates taken during the first and last 10 seconds of the one-minute recovery period for the modified KPRST compared against treadmill VO2 max values yielded correlations of --0.25 and --0.27, respectively, indicating that the modified KPRST is a poor predictor of cardiorespiratory fitness for the population studied. These results suggest that agencies should carefully validate any predictive measure of cardiorespiratory health and performance before adopting that measure for screening purposes and cardiorespiratory classification.