No one pushes harder than the skipper: Richie McCaw is still the fittest All Black

Is he the Terminator? Skipper is still the fittest All Black despite age and a history of injuries that would have stopped lesser men.

After a first day mostly spent being photographed and fitted out with new kit, day two of the All Blacks' training camp had a decidedly more physical theme with the players put through brutal fitness testing.

Basic conditioning has been the one undisputed area where the All Blacks have continued to set global standards in the past few years.

The chasing pack has closed the gap on many fronts - perhaps some countries have even gone ahead in specific areas such as scrummaging - but when it comes to aerobic capacity, the All Blacks still believe they have an edge over the rest of the world.

It has been a hallmark of their game in the past two years to dominate the final 10 minutes of a test. It's in those oxygen-starved final exchanges where they have come into their own - hauling back Ireland in 2013 and Australia last year. The All Blacks are lean and they are fit.

But they want to be leaner and fitter.

World Cup games will go to the death. The final 10 minutes will be rich with opportunity if the All Blacks have the lungs and legs to take advantage and that was really what was being driven home yesterday - that all players have to keep pushing themselves harder and harder over the next few months.

And no one pushes harder than the skipper. Once again, as he always does, Richie McCaw led the way in the various running tests.

He was joined up front by veteran Andy Ellis and the two of them set the standards through a range of sprint repeats and endurance work.

"You know you can't stay with them so you try to keep as close to them as you can," said fellow Crusader Ryan Crotty. "It is impressive - they are aerobic beasts those guys. They are fit. It is a strong part of their game and attributes they have to have to be able to play their game."

Ellis, of course, has every reason to try to make an impression while he's with the All Blacks as he remains an outside bet to force his way into the World Cup squad. At the moment, he's ranked fourth in the pecking order - behind Aaron Smith, TJ Perenara and Tawera Kerr-Barlow.

Kerr-Barlow hasn't played first-class football since he damaged his knee in South Africa last year but he is expected to play club games and for the Maori before being available to play for the All Blacks.

His resilience, mental strength and desire to work his way back to full fitness have impressed the selectors, but Kerr-Barlow still needs to jump the final hurdle of showing he's back somewhere near his best.