Of course every coach uses methods from sport psychology to improve ultimate performances.
But we don’t really know how or why methodology works: self-talk, mental focus, attention, etc.
The brain is complex. Each athlete is different from the next.
A mental training plan for one might well be quite difficult for the teammate training beside them.
Sports Psychology Has an Evidence Problem
The benefits of training your mental skills are, by definition, all in your head. So how do we prove that it works?

