What my school taught me is drastically different from what my certifications taught me. School was about exercise science (what is best for clients). Certifications taught me about trends (what clients may want). Should certifications be evidence based or trend based? How do we reconcile what is best for clients with what they may want?
I was surprised by your question because the certifications I hold have provided me with great education in the field of exercise science. Not one of them deals with ‘trends’.
When I look at trends, I assess them against the science I have learned and decide whether to incorporate a trend in my way of training or to ignore it.