All Blacks captain Kieran Read has reminded critics who felt he was past his best that he only fully recovered from back surgery towards the end of the 2018 season.

The 33-year-old underwent surgery on his back late last year and was out of action until the end of June for the Canterbury Crusaders. He did not play a Test until the southern hemisphere's Rugby Championship in August.

The number eight was not at his rampaging best when he returned and several northern hemisphere commentators have said in summing up the 2018 season that he appeared to be a shadow of the player who won the 2013 World Player of the Year award.

Read, however, said that it had taken him until the All Blacks' end-of-season tour in Europe - which included a defeat to Ireland in Dublin - to feel like he was getting back to full fitness.

"Getting over back surgery was probably the biggest thing for myself," he told New Zealand radio station Newstalk ZB. "It took a lot of time and effort.

"It's been 12 months since the surgery and it probably wasn't until basically the end of the year where I started feeling somewhat decent physically."

Read added that his fitness and health issues were a good sign heading into his final year in New Zealand rugby, having already decided to seek a contract overseas following the All Blacks Rugby World Cup campaign in Japan.

""Where I was at this point last year, the pain I was in, it [surgery] was needed," he said.

"It's been a fairly fast recovery in some respects. I've worked pretty hard at it and I'm in good shape now.

"So it bodes well to head into this off-season and pre-season feeling in really good shape."

Read has not said where he will play rugby after the 2019 World Cup, but felt going offshore would provide the perfect chance to give his young family a new experience.

"As a family it will be a good opportunity," Read said.

"My wife and kids have made a lot of sacrifices over the years I've been playing. It's probably the hardest thing. You appreciate that and know how much it takes out of them.

"Spending more time with them would be cool."