High force, resistance exercise (RE) is used to promote muscle hypertrophy and improved contractile function. When performed unaccustomed, or in excess, RE results in exercise-induced muscle damage (EIMD), muscle pain and decreased contractile function that may persist for several days. An appropriate model of muscle damage and repair EIMD is a non-ecologically valid model of RE training in RE-trained athletes. This study investigated the magnitude and temporal change in static and dynamic contractile function in RE-trained male and female athletes following an ecologically valid RE-training session. Subjects were RE-trained young (18-35y) male (MEN, n=11) and female (WOMEN, n=8) athletes. Isometric maximal voluntary contraction (IMVC) and angle of peak torque (APT) of the knee extensors (Con-Trex MJ; CMV AG, Dubendorf, Switzerland) and dynamic counter movement jump (CMJ) was measured prior to (BASAL) and 4, 24, 48 and 72h following an ecologically valid RE-training bout comprising ~ 50 repetition of a fixed mass barbell back squat (> 80% 1RM). Creatine kinase (CK) activity and perceived muscle soreness (visual analogue scale, VAS) were used as an analog of EIMD. Data are reported as % change from BASAL, mean [lower : upper] 95% confidence intervals and P-values adjusted for posthoc contrasts by time or sex. Minor perturbation in post-RE CK activity (MEN 24h, 126 IU.l-1 [76 : 176] ; WOMEN 24h, 89 IU.l-1 [55 : 123] confirmed the non-overt-EIMD RE-training bout. A significant decrease in IMVC (MEN -10.2% [-15.0 : -5.5], P = 0.003 ; WOMEN -14.8% [-25.0 : -4.6], P = 0.011) and CMJ. (MEN -13.5% [-18.3 : -8.7], P < 0.001 ; WOMEN -21.8% [-30 : -13.5], P < 0.001) was observed 4h post-RE. IMVC recovered by 24h and CMJ recovered by 72h for both sexes. The magnitude of decrease for the CMJ was greater for MEN than WOMEN (24h; MEN -9.6% [-13.4 : -5.7] vs. WOMEN -20.3% [-29.6 : -11.3], P = 0.046, d = 1.31: 48h; MEN -6.2% [-10.4 : -2.0] vs. WOMEN -24.9% [-35.2 : -14.6], P < 0.001, d = 2.05). There was no change in APT over time (P > 0.05, ω2 = 0.02). Muscle soreness increased throughout recovery, WOMEN reporting higher initial scores than the MEN (4.4 mm [3.5 : 5.3] vs. 6.0 mm [4.8 : 7.2], P = 0.036, d = 1.14). These data find a significant decrease in static and dynamic contractile function following ecologically valid RE training in RE-trained men and women and a differential recovery rate for static vs. dynamic function that was marginally greater in women. It is speculated that mechanical disruption to the excitation-contraction coupling accounted for the immediate force loss. Latent calcium-mediated myocellular disruption/remodelling may in part explain the delayed recovery of function and, potentially, the minor increase in CK activity.