Aerobic Fitness is of Greater Importance than Strength and Power in the Load Carriage Performance of Specialist Police

Police officers are required to carry external loads as part of their occupation. One means of preparing officers to carry loads is through physical conditioning. The aim of this study was to investigate whether strength, power or aerobic endurance had the greatest association with load carriage performance. Retrospective data from 42 male specialist tactical police officers (mean body weight = 88.8±8.25 kg) informed this study. Baseline data were provided for strength (1 Repetition Maximum [RM] bench press, deadlift, squat and pull-up), lower body power (vertical jump, 10m sprint) and aerobic ('beep' test) performance. In addition, officers completed three 5km load carriage trials (3 to 4 months apart) with 25 kg packs as fast as possible. Pearson's correlations were used to look for associations between measures with an analysis of variance used to detect changes in load carriage performance. Alpha levels were set a priori at 0.05. All variables of strength and power were significantly correlated with performance except for 1RM deadlift and the 10m sprint for the last two load carriage trails. Of all fitness measures, aerobic fitness was the most highly significant correlation with the load carriage trials (r=-0.712, -0.709 and -0.711 for trials respectively). Time to completion improved across the three load carriage trials (p<.001). These findings support the approach that optimal load carriage performance may be achieved by performing load carriage tasks in conjunction with aerobic fitness and full body strength/lower limb power training.