Effects of Eccentric Training Intervention on Performance During the Sprint, Drag, Carry Event of the Army Combat Fitness Test

Abstract

The purpose of this study was to determine the effect of introducing eccentrically focused movements into a normal Military training program on the Army Combat Fitness Test (ACFT). The fourth event of the test, the Sprint Drag Carry, was the focus of the research. Eccentric training has been shown to elicit a sprint performance benefit 10,13,19,27 as well as decrease injury prevalence 17,20,28,34,36, It was hypothesized that including eccentric movements would improve performance for this 250m shuttle sprint event. Twenty-two Cadets from the Indiana University ROTC program were recruited to participate in a 6-week training program. Participants were randomly assigned to one of two groups to conduct either 3 x 5 repetitions of a Nordic Complex (combination of Nordic hamstring curl and reverse Nordic hamstring curl) or 3 x 15 repetitions of a tempo-based body weight squat. Participants took a pre and post ACFT to measure the change in performance. Overall ACFT scores as well as three of the six events showed significant improvement; 3.1% (p<.001) improvement in overall score (out of 600), 6.7% (p=.001) improvement in Hex bar deadlift, 2.7% (p=.045) improvement to 2-mile run time, and 10.4 % (p<.001) improvement in Sprint Drag Carry performance from pre to post with no differences between groups. No injuries were reported during the training period. The results demonstrate there was an observed improvement from pre to post-test; however, it is more likely a result of a dedicated training program designed by the Army to improve ACFT performance than the addition of the movements.