The study aims to identify the effect rapid weight loss on some physiological and biochemical variables and their impact on physical and skill efficiency of wrestlers. The sample of this study included 28 junior wrestlers (at the age of 15: 20 years) was divided into 12 as basic sample and 16 as Exploratory sample . The researcher used the experimental approach and the main results indicated that weight loss ratios confined between 2.33: 7.69, which led to an imbalance in some physiological variables, Where pulse rate was increased at rest and systolic and diastolic blood pressure and respiratory efficiency was decreased. In addition to the lack of proportions sodium and potassium, calcium and magnesium salts, which led to a decrease in the level of physical and skill efficiency of the wrestlers under study.