Background and Aim: Aggression in adolescents is one of the common behavioral problems, which is associated with reduced psychological resilience, lower quality of life, and physiological disorders such as increased cortisol and decreased BDNF. The aim of the present study was to investigate the effect of eight weeks of high-intensity interval training on resilience, quality of life, cortisol levels, and BDNF in aggressive students.

Materials and Methods: This quasi-experimental study was conducted with a pretest-posttest design and a control group in a randomized manner. The sample consisted of 20 aggressive students (identified using the Buss and Perry Aggression Questionnaire, 1992) who were randomly assigned to two groups: experimental (n=10) and control (n=10). The experimental group underwent an eight-week high-intensity interval training protocol (three sessions per week). The dependent variables included resilience, quality of life, cortisol levels, and BDNF (measured using ELISA method). Data were analyzed using analysis of covariance and SPSS software version 26.

Findings: The results of covariance analysis, after controlling for the pretest effect, showed that the eight-week high-intensity interval training program had positive and significant effects on the dependent variables. For the resilience variable, the posttest mean scores of the experimental group were significantly higher than those of the control group (p=0.001). For the quality of life variable, the posttest mean scores of the experimental group also increased significantly (p=0.002). Cortisol levels in the experimental group decreased significantly (p=0.002). Additionally, BDNF levels in the experimental group showed