Objective: To assess the acute effect of a myofascial release protocol applied to the adductor muscles of the thigh on functional, biomechanical, and physiological variables. Methods: This study is a randomized, double-blind, two-arm crossover clinical trial that will analyze male water polo athletes aged 16 to 25 years recruited from a sports training center in the city of Bauru. Data related to the following parameters will be collected for the physical evaluation: functional performance, through the jump test; biomechanical, through maximum isometric torque of hip adductors, electromyography of the hip and gluteus medius muscles; and physiological, through the analysis of serum markers of muscle damage and inflammation, and heart rate variability. After the initial evaluation, the participants will be randomly divided into two groups: intervention group and sham group. Then, all participants will perform a game simulation. After the game, the participants will receive the intervention designated for each group. For the intervention group, a manual therapy protocol will be applied, based on myofascial release in the thigh region that presents trigger points. For the Sham group, a manual technique, called classic massage, will be applied, with superficial pressure, used to reach only subcutaneous tissues, without acting on muscles and fascia. This protocol will be repeated at four different times, always after the games. After a washout week, the participants will change groups and the data collection protocol will be applied again.