Complex Training and its Effect on the Speed Force and Quantities of Strength for Specific Distances and the Achievement of 400 Meters Freestyle Under the Age of 20 Years

Athletics in general, and in particular the 400-meter freestyle event, requires special physical preparationfor the parts of the body that greatly participate in the skillful performance so that the running processcan be performed in the correct manner and with minimal effort by matching the muscles of the legs,distributing the exerted force during the run and increasing its quantities, from this basis, we mustfocus on the strength component, because strength has a good effect in the final achievement of the400-meter freestyle, as modern training methods must be used here to improve the strength component,and among these methods is the complex training whose basis is the mixing of weight exercises withplyometric exercises where weight exercises are stimulated muscles well and with plyometric exercises,allowing contractions moving in a circle (lengthening - shortening), therefore, the importance of theresearch lies in providing data and information within the complex training to know its effect on theforce distinguished by speed and the quantities of strength for specific distances and the achievementof 400 free meters, by applying these double exercises together and because they have an effect on thedevelopment of the most important types of muscle capacity, either the problem of research and throughthe follow-up of the researcher for many training units for 400-meter freestyle runners in Kerbala, theresearchers noted the lack of trainers’ use of modern training methods that would raise the level of themuscular capabilities of runners and their reliance on traditional training methods, and the importanceof research is to perform exercises in a complex training method and to identify the effect of temporarytraining on strength distinguished by speed and strength quantities for specific distances and to achieve400 free meters.