The research aimed to identify: the development of a program to modify the muscular balance of the two sides of the body and identify the extent of its impact on some physical abilities and the development of digital achievement for junior swimmers in the 50 m freestyle, and the researcher used the experimental approach for a sample of (15) swimmers. Among the research tools: physical tests - dynamometer - muscular balance program. The researcher used the following statistical treatments: arithmetic mean - standard deviation - median - torsion coefficient - test "T" - correlation coefficient - improvement rates - equation to find differences in biting balance