12-weeks Of Resistance Training Elicits Varying Sex Responses In Strength In Military Recruit-aged Adults

Revised military physical performance tests incorporate more strength-based measures to reflect relevant operational demands of service personnel. Understanding sex-specific responses to training will enable improved design of training interventions for service members. PURPOSE: To investigate sex differences in measures of strength and power following 12-weeks of Resistance Training (RT). METHODS: Thirty-three recruit-aged (18-36 years) men (n=19) and women (n=14) completed a 12-week RT program. Changes in absolute (%1RM) and relative (kg/BM) squat strength were assessed. Changes in power were measured using Squat Jumps (SJ) performed at ~30% of squat 1RM performed on a force platform. Rate of Force Development (RFD) during the SJ was calculated from the initiation of the concentric phase to 100ms (RFD100) and 200ms (RFD200), respectively. Peak force was derived as the maximum force (N) attained during the concentric phase of the SJ and was normalized to body mass. Mann-Whitney U tests were used to compare change distributions between men and women (α=.05). RESULTS: Change in SJ peak force was significantly greater in women (Mdn=46) than men (Mdn=-291)(U=195, p=.024) but relative squat strength increased more in men (Mdn=0.96) than women (Mdn=-0.09)(U=27, p