Science tells us a lot.  Mainly, the direction to head and the foundations to build on.  However, if all we did was "apply" what science finds, there are so many necessary aspects to performance that would be missed.  Sadly, some choose to keep their heads only in the texts and labs - all-in-theory... while others see the holes in the approach and rely solely on real-world application.  Unfortunately, this can lead down paths that will ultimately have people backtracking to get back to neutral when they find out there are holes in their thinking.  Enter, the integrated approach.  Driven by science, but only added to the system when proven by the athlete.