Dear Ricardo Barros,
to express opinions about “principles of training” it needs, at least, to definite what is “principle of training” by general point of view (for example, the principle of Dynamic Correspondence is not the principle of training but the principle of the SST means selection).
This is a question not for internet forum, but for the International Congress dedicated to the theoretical problems of the sport science.
But, I agree with you, there are too many fragmentary researches dedicated to discover what has been discovered many years ago. This happened also because most part of my colleagues prefer to make experiments often without the theoretical thesis to be demostrated.
A great Italian scientist, Alessandro Volta, wrote “there is nothing more practical than a good theory”