2384 Research has suggested that maximal eccentric (ECC) strength is underestimated by 20–60% compared to concentric (CON) strength. However, a dearth of research testing this assumption in resistance exercises between genders exists. PURPOSE: To determine the difference in maximal ECC and CON strength for different exercises in men and women using a recently published method for determining maximal ECC strength. METHODS: Nine healthy male (M ± SE 25.44 ± 3.78) and 10 healthy female (M ± SE 23.40 ± 4.33) recreational weightlifters with resistance training experience participated in the study. Two sessions were performed to establish CON and ECC one repetition maximums (1-RMs) for lat pulldown (LTP), leg press (LP), bench press (BP), leg extension (LE), seated military press (MP), and leg curl (LC) on a weight stack machine (Master Trainer, Rayne, LA). Equipment was modified to isolate ECC/CON contractions using steel bars and pulleys. A 3-set warm-up followed by a counterbalanced and randomized trial was employed to determine the CON and ECC 1-RM. The 1-RM was determined using a 3-second cadence to completion. If the subject failed to maintain the 3-second cadence or could not complete the pre-determined range of motion in the allotted time, the lift was considered a failed attempt. Within two weeks, subjects returned and completed a retest-trial. RESULTS: Test-retest reliability ranged from r = .98 to .99 for all resistance exercise trials. Men demonstrated consistent ECC strength within previously proposed parameters (LTP = 46%, LP = 47%, BP = 37%, LE = 36% MP = 53%, LC = 33%). Women's strength exceeded the proposed parameters for greater ECC strength in four exercises (LP = 69%, BP = 142%, MP = 212%, LC = 83%). The percent difference in ECC and CON strength was greater for the women than men for BP, LE, MP, and LC, pp<.05. CONCLUSIONS: Data confirmed men's ECC strength was 20–60% greater than CON in men and even greater for women. The differences between genders may be due to muscle mass and biomechanical differences between men and women.Table