The research aims to design a proposed training program using the PNF and muscular strength training methods to develop the center area (CORE) for emerging monofin swimmers in order to identify the impact of the program on: - 1- The digital level of the monofin swimmers in the research sample. 2- The strength of the muscles of the center area (CORE). 3- Level of flexibility of the pelvic joint 4- The correlation between the variables under study and the digital achievement of emerging monofin swimmers. The research sample From the swimmers of the Sharkia Sports Club for the age group (14-15 years) (boys), registered with the Egyptian Diving and Rescue Federation for the training season 2021-2022 AD, and their number was (16) swimmers who were divided into two groups, experimental (8 swimmers) and control (8 swimmers), with a percentage of ( 66.66% of the total population of (24 swimmers), and (8) swimmers were randomly selected from the total research community for the exploratory study.