Christian Lealiifano is feeling as fit as ever, as he prepares for a Super Rugby return in Canberra.

Lealiifano returned to Brumbies training last week after a three-month stint with Irish side Ulster, an experience that he said allowed him to step outside of his comfort zone.

“I think that was probably the big idea of heading over there was to refresh, come back here rejuvenated and to experience that kind of footy,” he said.

“It was sensational.

“I’m really grateful that the club allowed me to do that and to get out of this - I've only known Brumbies my whole life and to experience a different culture and a different rugby culture was really enjoyable for me.”

The Ulster contract was Lealiifano’s first consecutive run of games since he was diagnosed with leukaemia in 2016, and said it was hard to compare how he felt now compared to before his illness.

“It's hard to say if everything's back to normal,” he said.

“You're always looking for that constant improvement.

“I think heading over there was just about seeing where I was at and I felt like I was in some consistent form and back here now to jump in with the boys and try and improve my game again.”

The 30-year-old is a shade lighter than he was before he became sick, but said that wasn’t necessarily a bad thing.

“I don't think I want to get to that weight again,” he said.

“I'm feeling a bit fitter and a bit more agile playing at the weight I am now.

“It feels a bit different but I guess I'll just work around that and try and adapt.

The Brumbies will announce their 2018 captain later this week but Lealiifano said he wasn’t necessarily expecting to step back into a formal leadership role.

“Any way I can add value to this side I'll be happy with, whether that's a leadership role or a captaincy role, is something you sort of look into but I wouldn't say I want it or would be looking at.

“I think it's something that the coach has got to assess that situation and go from there.

“I think we've got some healthy leaders and some good young guys that have been developing in that area as well.”

The Brumbies play their first 2018 trial on Saturday against the Rebels and coach Dan McKellar said Lealiifano would be watching on after a heavy load in Ireland.

“I think the big difference is coming from the training load he's had at Ulster and Ireland compared to where we're at at the moment,” he aid.

“They're obviously in the thick of their season and going from one game to the next whereas here we're at a peak time in preseason.

“It's just making sure we manage him wisely there and not ask too much of them.”