U.S. Navy Physical Readiness Test Scores Do Not Predict Performance On Simulated Shipboard Firefighting Activities

Shipboard firefighting (SBFF) requires strength, cardiovascular and muscular endurance, and power to handle physically demanding tasks in high-stress, high-risk environments. The Physical Readiness Test (PRT) is used by the U.S. Navy to assess the general fitness of sailors but its relevance to SBFF performance is unknown. PURPOSE: Evaluate the PRT and other fitness assessments as predictors of SBFF performance. METHODS: Seventeen healthy adults (24 ± 5 y, 177 ± 8 cm, 81.7 ± 14.0 kg) completed the PRT, fitness tests, and SBFF protocol in protective garments on three separate days. The PRT includes a two-minute push up test, a forearm plank until failure, and a cardio test. Participants chose between a 1.5-mi walk/ run, 2000 m row, 450 m swim, and a 12 min stationary bike test. The PRT was graded by number of pushups completed, time of plank, and cardio test. Other fitness tests included a 3-repetition maximum (3RM) deadlift, 55 m shuttle run, vertical jump, and VO2 max. The SBFF protocol consisted of a 80 m scene entry walk, a two 20 kg bucket-carry up and down stairs, and lifting, pulling, and striking (LPS) tasks. Heart rate (HR) and core temperature (Tc) were collected at the end of each task. Pearson’s correlation coefficients were used to test the PRT scores and the other fitness test results as predictors of the number of LPS tasks completed. For variables identified as significant predictors, participants were grouped by tertiles of these variables and separate a priori survival curves were generated with differences between curves tested by the logrank test for trend. RESULTS: The group completed 14 ± 6 SBFF tasks (min = 5, max = 25). There were positive correlations between deadlift (p < 0.01; r = 0.63) and VO2 max (p = 0.02; r = 0.54) and LPS tasks completed. There were no correlations between LPS tasks completed and any PRT test or the overall PRT score. Participants were grouped by tertiles for deadlift (≤113, 113-133, and ≥ 133 kg) and VO2 max (≤41, 41-48, and ≥ 48 ml·kg-1·min-1). There were significant differences between deadlift survival curves (p = 0.03) but not VO2 max survival curves (p = 0.06). CONCLUSIONS: The PRT is not a good predictor of SBFF. The 3RM deadlift and VO2max are predictors indicating that both whole body strength and cardiovascular endurance are important for SBFF. Supported by: Office of Naval Research N000142312829