A North Island DHB's missed the mark on motivation.

An image tweeted by MidCentral District Health Board read: "Don't stop when you're tired, stop when you're done."

While it may seem like lighthearted social media banter to some, the medical profession is taking the implication very seriously.

Association of Salaried Medical Specialists Chief Executive Ian Powell said the tweet hits a sore spot for the workforce.

"DHB's should not be encouraging their staff to get more tired than what they are. They should be taking responsibility for ensuring that they are not get as tired in the first place."

Powell said it's not a sentiment burnt-out hospital specialists want to hear.

"In the case of hospital specialists, we have a 50 per cent burn out rate. That state of health is not conducive to quality patient care."

Powell said DHBs should be taking note of how tired their staff are - rather than encouraging them to work past their limit.

There is a danger to patients if doctors are forced to work through fatigue, he added.