The phrase "to train the trainers" means teaching people who will then go on to teach others.
Sentences with «to train the trainers»
Retailers should ask specifically what type of training the trainer employs. (petbusiness.com)
I think you succeeded in training the trainers, rather than just passing a few exercises on. (dogtrainingpost.com)
By training trainers and users, the impact being sought is to reduce the dependence of developing countries and their institutions on existing expertise and know - how in the developed countries. (uncclearn.org)