The eccentric chin-up is one of the greatest tools you have for developing your client's strength to achieve a bodyweight chin-up goal. Eccentric training is a powerful modality for building strength and I highly recommend using it. My biggest point with using this exercise is client safety in a health and safety context. It is easy for your client to fall and if you are using a box to get them to the initial position, they could hit their head. Your first goal is to do no harm so recognise the risk and manage it.
Dave Stewart
The Trainer’s Trainer