Effect of carrying different military equipment during a fatigue test on shooting performance

This study investigated the effect of a 3-km walking test (3kWT) carrying different military equipment on shooting performance, rating of perceived exertion (RPE), heart rate (HR), and test time. The relative combat wear and backpack weight (as percentage of soldier's body weight [%BW]) was reported and, along with HR, its relationship to marksmanship variables was tested. Thirty-nine Spanish Army males walked as fast as possible to complete the 3kWT in the following conditions in a randomized order: unloaded walking; wearing the combat uniform; and carrying the combat uniform plus combat backpack. A shooting test was completed before and after the 3kWT. The HR and RPE were evaluated. The marksmanship variables and HR were analysed using a two-way repeated measures ANOVA, and a repeated ANOVA was also used for 3kWT completion time and HR reserve analysis. Correlation analyses were performed between the equipment's weight, HR, and marksmanship variables. The results showed that shooting score decreased after the 3kWT in both load conditions (p < 0.001). The 3kWT time, RPE, and HR increased from control to load conditions, and also between load conditions. The HR reserve showed no significant effects between conditions. The %BW of the backpack condition negatively influenced aiming accuracy (r = -0.35; p = 0.04) and cleanness triggering (r = 0.37; p = 0.03). Correlations between HR and shooting variables were non-significant. In conclusion, wearing the Spanish Army combat wear and backpack resulted in shooting performance degradation. Furthermore, fatigue and RPE increased and this could decrease physical marksmanship and performance capacity in combat situations.