Hi Dimitris. I’m not sure exactly how to answer your question, but to my mind the very essence or definition of “functional” training would tell me that this is an appropriate form of exercise for EVERY client. The real issue comes down to how much, or to what degree we use that method of training, and the answer to that question is very ‘client-specific’ (depends on the client’s needs).
I hope that this helps.
The answer to your question is yes for many obvious reasons. It doesn’t matter the type of training the client is engaged at, as long as it is designed to help the client to meet his goals and needs. Sometimes it can be more sport specific or job related, but at the end it’s important to incorporate functional training into every fitness program.