Ziebell has just completed North's three-week high-altitude training camp in Utah, with the Roos scheduled to fly home on Friday (AEDT).
The midfielder told NMFC.com.au he has been able to shed weight in Utah without sacrificing any strength.
"I've felt really good this camp. I've dropped a couple of kilograms which is nice and helped me get through the running," Ziebell said.
"But I'm still as strong as what I was, which is important as well.
"The altitude plays a part (in slimming down) with all the boys, so I'd expect to put a couple of kilos back on when we get back to Melbourne, but the body's feeling really good at the moment."
So far this pre-season Ziebell has met his main goal of completing every training session.
Too often in the past this has not been the case.
Ziebell suffered a broken leg in each of his first two AFL years, 2009 and 2010, which restricted the amount of running he could do over the ensuing pre-seasons.
Even last pre-season, Ziebell was sidelined for several weeks by minor knee surgery.
But this year Ziebell seems well positioned to capitalise on the steady fitness gains he has made in recent seasons and take his aerobic running to another level.
"I know if I do every session it's going to hold me in pretty good stead for the year," he said.
Ziebell said this year's Utah camp, the club's fourth consecutive visit to the western US state, had been fantastic, with the players driving each other to new training levels.
Part of the large group of players drafted by the Roos since 2008, Ziebell is confident the time North's emerging players have spent together over recent seasons will start to pay off in 2014.
"The majority of our group has been together for the last four or five years and it's been really important that we've stuck together.
"We've had some pretty tough times, but we're really looking forward to this year and trying to improve over the pre-season and (then) getting out there and starting to playing footy.
"That's what all the fans want, that's what all the players want as well."
Twitter: @AFL_Nick
