It takes energy to tackle, get up off the ground, and tackle again and again. The Wallabies, so good at it in the first half against the All Blacks in a superb defensive performance in Sydney had to pay for their efforts at some stage in this gripping Bledisloe Cup test.
It was straight after halftime, as it turned out. Green and gold heads dropped once Jack Goodhue went over from 50m out for his first try in test rugby – one he'll never forget – and they dropped further once the All Black scrum, that Rolls Royce of set pieces, turned the screw.
The tries flowed from there, a case of the All Blacks reaping the rewards of some serious hard work as they put one hand on the Bledisloe Cup once again ahead of the return at Eden Park next weekend. It's a long way back for the Aussies, who were supported by those who poured on to the (badly-delayed) trains in central Sydney with hope in their hearts.
There are positive signs for Michael Cheika's men, though. The All Blacks wouldn't have been shocked by the Wallabies' first half defensive effort because they would have been preparing for exactly that.
There was an edge to coach Steve Hansen this week; he knew what was coming and how much the Australians have improved compared to this time last year.
At halftime 12 months ago the All Blacks had already brought up 40 points, but this time the Wallabies were like men possessed as they sprinted into the All Black faces in order to deny them time and space. They attacked the All Black lineout, too, with success, and the breakdown too of course but with Michael Hooper and David Pocock on board that almost goes without saying.
This was a high-octane test played in front of 66,318 at ANZ Stadium and no way as easy as the scoreline would suggest. But in the end the All Blacks' composure after a rocky start, and their ability to constantly ask questions of the Wallabies defence, allied with their scrummaging excellence, got the job done.
Ryan Crotty was an early casualty – with yet another head knock – but it was a credit to Goodhue's maturity and Anton Lienert-Brown's ability, that the All Blacks didn't lose anything. Rieko Ioane left the field with a leg injury in the second half, but the Wallabies suffered the greater misfortune when prop Sekope Kepu left the field.
Already under pressure, the Wallabies set piece virtually imploded. Israel Folau's departure with injury was like salt in the wounds after that.
Goodhue, the 24-year-old playing his second test, was brilliant for the All Blacks and if anyone deserves credit for driving the Aussies into exhaustion it was him. There are few better in the All Blacks at putting teammates into space – or taking advantage of a two-on-one attacking scenario.
He will get the plaudits and he deserves them, with his teammates' composure under pressure, Brodie Retallick's incredible workrate, and the eight-man shove just behind.