"The emphasis wasn't always on skill but things that come free such as work-rate and fitness. You don't have to be good to do stuff like that. You just need a good mental attitude. The mantra was: We want to be the fittest, we want to be the best.
"So they'd get every last drop out of you.
"Under Gats it was the hardest I've trained and probably the fittest I've ever been."
James said he was tiling a toilet in his new house when Hansen called him with the news that he hadn't made the 2003 World Cup squad.
He said: 'Paul, it's Steve. I'm just ringing you to let you know that you haven't made the World Cup squad'.
"He went on to give me a load of compliments and told me to maintain my form, saying I was young and would come through. He made you feel good about yourself and it gave me a massive confidence boost."
Hansen still keeps in touch as well, James reveals.
"He doesn't forget you. Every time we played the All Blacks, he would come in and say: 'All right, Paul. How's it going?' Mike Cron, the scrum coach, would do the same."
36-year-old James still plays for Ospreys, having topped more than 200 caps for the Welsh club.