Research aim.
This research aims to improve the numerical level of 50 meters butterfly swim by using Tempo Trainer tool.
Research hypotheses:
1-     There are statistically significant differences between the pre and post measurements in the numerical level of 50 m butterfly swim for the benefit of post measurements.
Research approach:
The experimental approach used one experimental group with the pre and post measurement standard design.
Research Sample:
The subjects for this experiment were competitive butterfly swimmers of well-trained swimmers competing from Wadi-Degla club (n=7) divided to (2) swimmers (1) male, (1) female for the sample survey, and (3) males, (2) females for the experimental sample.
Conclusion:
1-Training with the Tempo Trainer tool has improved the numerical level of 50 meters butterfly swimming for junior swimmers age (15-14).
2- There is a difference in the change percentage between the pre and post measurements of the research sample on the numerical level of 50 meters butterfly with a change rate of (2.9%) for the benefit of post measurements.