Studying the effect of strength training (plyometric and isometric) on some blood components in junior handball players during the competition phase (17, 18 years old).

Abstract

In strength training, coaches have resorted to using various methods, including plyometric training, which is suitable for all ages, levels, and abilities, and is also appropriate for all sports activities where explosive power plays a significant and important role. Plyometric training also enhances muscle endurance for stretching exercises through the presence of both concentric and eccentric contraction phases (Darwish Kamal El-Din et al., 1998, p. 34). Another method used in strength training is isometric training, which has gained considerable traction among coaches. This type of training relies on the change in electrical potential within the nerve cell as a result of a sufficient nerve signal, without changing muscle length. This type of training is performed without muscle contraction or extension and plays an important role in increasing tensile strength and speed-strength and maximum strength when applied in conjunction with other types of strength training (Weineck J, 1997, p. 216). In order to ensure good performance in competition, it has become necessary to take into account strength training methods, as both plyometric and isometric training have become widely used at the level of special training programs. Strength training is applied by using high-intensity physical exercises that cause physical transformations that appear in muscle size and the accompanying changes in body weight. As for changes in blood characteristics, they appear at the level of red and white blood cells and the percentage of hemoglobin, etc., in addition to some changes in hormones that are activated by increasing the intensity of physical exertion, such as male hormones, growth hormone (GH), and cortisol, etc. (Wilmore J.H, Costil D.L, 2006, P 166). Furthermore, every high-intensity physical activity leads to a range of biological consequences, which are most pronounced at the muscular level. Hoppeler H et Olgivie R.W. (1989) indicated that athletic training based on eccentric muscle contractions results in biological changes in hematological and urinary characteristics (Rieu M et Barrault D, 1989, p. 21). Since various types of muscle contractions in strength training affect muscle tissue, a significant immune response is observed, characterized by increased activity and mobilization of different types of white blood cells after physical exercise. Bricout V.A. et al. (2006, p. 336) indicate that the immune response to high-intensity exercise manifests primarily in leukocyte activity, which migrates from the circulatory system to damaged tissues, along with the infiltration of neutrophils and phagocytic cells (Camus G et al., 1994). According to Northoff H et al. (1995) Cell migration begins within the first 45 minutes of exercise and continues for the next 5 days. The importance of phagocytic cell leakage is directly proportional to the magnitude and extent of muscle tears resulting from strength training. Therefore, our study aimed to determine the effect of both plyometric and isometric strength training on certain blood components by taking laboratory blood samples before and after each training program.