Rapid and extreme weight cutting is a common practice among combat sports athletes aiming to compete in lower weight categories, yet its effects on performance and physiological function remain a significant concern. This study aimed to investigate the impact of short-term, severe weight reduction on competitive performance, cardiovascular parameters, muscular strength, and endurance in athletes participating in wrestling, judo, and mixed martial arts. A total of 40 male athletes aged 18–28 years, all with at least three years of competitive experience, were recruited and divided into two groups: one undergoing extreme weight cutting (losing 5–8% of body weight within 48 hours) and a control group maintaining regular weight. Performance assessments included agility tests, reaction time, grip strength, anaerobic power, and simulated combat bouts, while physiological measures comprised heart rate, blood pressure, hydration status, and blood lactate concentration.