High-intensity tasks with external load in military applications: a review.

This article provides a synopsis of the limited investigations examining the impact of external load (EL) on performance of high-intensity tasks under load (HITL), EL training intervention effects on HITL performance, and injuries from EL training. Repetitive lifting tasks and initiation of locomotion, such as rapidly moving from a prone position to sprinting appear to be more hindered by EL than maximal sprinting velocity and may explain why training with EL does not improve obstacle course or prolonged (200-300 yard shuttle) drills. EL training appears to offer very little if any benefit for HITL in lesser trained populations. This contrast results of multiple studies incorporating ≥ 3 weeks of prolonged hypergravity interventions (wearing EL during daily activities) in elite anaerobic athletes, indicating EL training stimulus is likely only beneficial to well-trained soldiers. Women and lesser trained individuals appear to be more susceptible to increased injury with EL training. A significant limitation concerning current HITL knowledge is the lack of studies incorporating trained soldiers. Future investigations concerning the effects of HITL on marksmanship, repetitive lifting biomechanics, efficacy of hypergravity training for military personnel, and kinematics of sprinting from tactical positions with various EL displacements and technique training are warranted.