AbstractThe purpose of this study was to determine the effects of 8 weeks of Copenhagen exercise on hip adduction eccentric strength, hip adduction/abduction eccentric strength, and change of direction ability, which are risk factors for groin injuries. This study was designed as a cluster randomized controlled trial in which a team was defined as one cluster of female high school soccer team. The recruited twenty-four participants were divided into a Copenhagen exercise group(CAE; n=12) and Nordic curl exercise group(NCE; n=12), and then the intervention was applied for 8 weeks. As a result, application of the Copenhagen exercise to female elite high school soccer players for 8 weeks resulted in an increase in hip adduction eccentric strength and hip adduction/abduction eccentric strength ratio at the non doninant leg, which are risk factors for groin injury, and improved change of directio ability, a performance related factor. Therefore, the Copenhagen exercise is recommended to be included in warm-up program to reduce risk factors for groin injury as well as improve change of direction ability.