Hi Celso. To my mind, ‘functional training’ is a generic term for any type of training that is useful or “functional” for the person performing the exercise. That being said, something as simple as a pull-up can be considered functional training under the right set of circumstances. Pretty much ALL exercises are functional, it just depends upon the person performing the exercise and the intent or function that the exercise can be used for. Both the examples that you used in your question (cardio and weight lifting are, and can be considered “functional training”). So, I don’t see this big movement towards ‘Functional Training’ as any big deal. If we as trainers are truly taking our clients needs, goals, strengths and weaknesses into account when we design their program, we ARE in effect performing ‘functional training’ for them.
I hope that this helps.