Physiological responses of female load carriage improves after 10 weeks of training

Purpose: This study aimed to characterize and evaluate female-specific physiological and perceptual responses during a load carriage walking task before and after a 10-wk physical training program. Methods: Eleven recreationally active women (age, 21.5 ± 2.2 yr; stature, 1.66 ± 0.8 m; body mass, 64.4 ± 6.8 kg) completed a load carriage task (5 km at 5.5 km·h^-1, wearing a 23-kg torso-borne vest) before and after a 10-wk physical training program. Physiological (i.e., maximal oxygen uptake, carbon dioxide production, respiratory exchange ratio (RER), breathing frequency, and pulmonary ventilation) and perceptual (i.e., rating of perceived exertion [RPE]) responses were collected during the load carriage task. Additional physical performance measures (i.e., push-ups, sit-ups, beep test, and isometric midthigh pull) were collected in a separate session before and after the 10-wk of training. Results: Compared with before training, maximal oxygen uptake requirements reduced during the load carriage task (P < 0.05), whereas heart rate and RPE remained similar. RER reductions over the 5-km march indicated a shift toward fat utilization, with other physiological responses demonstrating an increased ability to sustain the metabolic demands of the load carriage task. Increases in push-up and isometric midthigh pull performance demonstrated improvements in upper-body muscular endurance and lower-body strength after the 10-wk training program (P < 0.05). Conclusions: During a standardized load carriage task, physiological and perceptual responses indicated physical adaptations to specific training in women. Although positive physiological responses were elicited, additional strategies (i.e., cognitive resilience training, female-specific vest design to reduce pain burden) to build load carriage task-specific resilience (perceptual responses) may be required.