Objective: To investigate the sex-related differences in single-task performance through motor torque, cognitive tasks and walking speed, and the combined dual-task costs (DTCs) considering both motor and cognitive performance in young adults. Methods: Sixty-seven non-athletic subjects 37 females and 30 males were enrolled. The study measured their knee extension muscle torque using an isokinetic strength dynamometer and their walking speed using the one step app. these assessments were performed both with and without a cognitive task, and the DTCs were calculated. Results: The females exhibited significantly larger motor performance dual task effect through (torque-DTC, speed-DTC) compared with males while exhibiting smaller cognitive dual task effect with muscle torque and speed. Conclusion Deterioration in motor performance during muscle force production and speed during dual tasks was large in females compared to males, whereas males experience a decline in cognitive ability when performing dual tasks compared with females.