The Frappier affiliated program near me offers sports specific training, including tennis.Tom is right, programs are springing up in a lot of places. The Frappier program is not specific to tennis, it is for athletes of any movement sport and can be adjusted for a particular athlete.
This link gives a nice explanation.
3 - 4 sessions per week is ideal, but it cuts into court time too much. 2 sessions per week is fine (according to the program near me).