All Black and Blues scrumhalf Piri Weepu is back … and he's fit and raring to go.

The World Cup winning scrumhalf returned to Auckland this week on promotional duties with the All Blacks and called into Blues HQ for a fitness session Monday.

More than 10 kilos lighter than at the same time last year and with hugely improved skin fold measurements, Weepu cut a lean figure as he got stuck into some conditioning games in the sweltering heat at Unitec.

"I thought I should keep up with things this year and try and make sure I start a lot better than how I was shape-wise last year," the 29-year-old said.

"I've been trying to run the roads and run up some mountains and do anything I can that's cardio along with a little bit of weights in between spending some quality time with my family."

Weepu's weight issues last year were well documented in the media as he came into his first season with the Blues out of shape, but he has been putting in the hard yards and the results are clear for everyone to see.

"I'd like to say I'm in pretty good nick," he said.

"I'm probably around the same as I was on the end of year tour last year so I've been trying to keep everything down and make sure that my numbers are right this time around. I'm pretty excited about it because I'm not as heavy as I was last year when I first came into camp so it's pretty good."

Blues head coach Sir John Kirwan was thrilled to see his world-class scrumhalf return in great shape and was eager to put the tedious story to rest.

"He doesn't have to be here firstly which is fantastic and this story is officially dead - he is fit, he is well and he is raring to go," Kirwan said.

"He's come back in and his body weight is good and his skin folds are good. He's not ready to play yet but he's been on holiday and he's done a fantastic job so we're excited to see him.

"It's good to have him in here training with the boys so it's a done deal, talk about something else please."

With a new coaching setup, a new team and a fresh air of excitement and optimism in the team, Weepu said he couldn't wait to get back into training.

"It's a new year, a new start and new beginnings so it's just trying to make sure that I do everything possible this time around to make the most of my opportunities.

"Obviously there are two young boys (scrumhalves Jamison Gibson-Park and Bryn Hall) that are in the team so I'll be trying to help them out and I'm pretty sure they'll be nipping at my heels but if not I'll be keeping them honest as well.

"Coming back and looking at the shape the boys are in and how mobile they are, especially the big boys like Ofa that can … get around really well, all that hard work has been paying off so hopefully with all that young talent that we've got we can turn some heads this year."

Weepu will resume his All Blacks promotional duties for the rest of the week and officially return to training with the Blues on January 30.