Deep Impact: How Rumination About Martial Law Depletes Personal Resources and Reduces Mastery Experiences

South Korea’s 2024 declaration of martial law triggered a sudden, uncontrollable sociopolitical crisis that disrupted citizens’ psychological and physical well-being. Drawing on self-regulation theory, this study examines how evening rumination about martial law undermines next day functioning by depleting core personal resources which subsequently impairs mastery experiences at home. Using an eight-day experience sampling method with 230 South Korean employees (1,781 observations), we find that nighttime rumination predicts greater depletion of personal resources the following workday. In turn, cognitive and emotional depletion—but not physical fatigue—are associated with reduced mastery experiences in the evening. Furthermore, lunch meal quality acts as a buffer, attenuating the association between rumination and cognitive depletion, and marginally buffering emotional and physical resource loss.