Siswa atlet adalah salah satu kelompok siswa yang sering kali mengalami underachievement, meskipun siswa atlet tersebut termasuk siswa berbakat intelektual gifted. Underachievement ini disebabkan oleh rendahnya kemampuan regulasi diri dalam belajar. Intervensi Self Regulation Empowerment Program SREP terbukti dapat meningkatkan regulasi diri dalam belajar dan prestasi akademik melalui penelitian Cleary Zimmerman 2004, Cleary, Platten Nelson 2008, Cleary Platten 2013 dan Giri 2016. Pada penelitian berdesain single subject experimental study ini, peneliti ingin melihat pengaruh SREP dalam meningkatkan regulasi diri dalam belajar dan prestasi akademik siswa atlet SMA dengan gifted underachievement. Data diperoleh dari pengukuran Motivated Strategies and Learning Questionnaire MSLQ, Self-Regulation Strategies Inventory SRSI Parent and Teacher Rating, dan nilai pada mata pelajaran PKN, Matematika, serta Sosiologi. Melalui pengujian statistik reliability change index RCI disertai dengan analisis kualitatif, diketahui bahwa SREP dapat memberikan peningkatan signifikan pada regulasi diri dalam belajar RCI = 3.58, p Student athletes are one of the group of students who often experience underachievement, even though the athlete 39 s students are intellectually gifted. This underachievement is due to the low self regulation ability in learning. The Self Regulation Empowerment Program SREP interventions proved to improve self regulation in learning and academic achievement through study from Cleary Zimmerman 2004, Cleary, Platten Nelson 2008, Cleary Platten 2013 and Giri 2016. In the study of single subject experimental study design, the researcher wanted to see the influence of SREP in improving self regulation in learning and academic achievement of high school athlete with gifted underachievement. Data were obtained from measurement of Motivated Strategies and Learning Questionnaire MSLQ, Parent and Teacher Rating Self Regulation Strategies Inventory SRSI, and grades on PKN, Mathematics, and Sociology subjects. By testing the reliability change index RCI statistics along with qualitative analysis, it is known that SREP can provide significant improvement in self regulation in learning RCI 3.58, p |