Comparison of mean scores and standard deviation

20 subjects are given a flexibility test (pre test)

A six week flexibility training program is conducted

20 subjects are re tested on their flexibility (post test)

If the program is successful, what would happen to mean scores and deviation scores?

Pre test: 10,9,11,9,10,11,12,8,9,10,8,7,9,8,10,10,7,9,11,9

Post test: 12,11,13,11,11,14,12,12,14,12,11,11,13,12,13,14,10,11,14,12