Brook and his charges are currently Down Under and will take on the hosts in three ODIs, starting on 13 November in Perth, which will be followed by a five-match T20I series.
England have been focused on setting a standard in their training and preparation ahead of the 50-over contests, with fitness a key component in the sessions.
Brook said: "With the World Cup 12 months away, it's a good period now to really start to try and nestle down, hone in on the skills and the lessons that we've learned.
"Key thing is to try and be one of the fittest and strongest sides in the world. To be able to try and dominate throughout that competition (World Cup).
"Obviously, whether you win or lose isn't always there. You can never guarantee that, but the off-field...you can guarantee the off-field preparation can be a lot better. Can really help towards winning games."
Jacob Bethell will return to England's batting line-up after recovering from is ankle injury, and the tourists will have a selection dilemma after the success of Ben Duckett and Tom Banton as an opening partnership in the recent ODI tri-series in Pakistan.
"That's a conversation for me and Baz (Brendon McCullum, England's white-ball head coach) to have down the line," Brook said. "He's (Bethell) obviously just coming back from fitness now. He's a very good player and could be a very vital player for us moving forward."
England have suffered a blow ahead of their white-ball matches in Australia with the news that fast bowler Josh Tongue has been ruled out of the three-match ODI series with a toe injury.
Australia seamer Mitchell Starc has returned to the top of the ICC Test bowling rankings after reclaiming his spot from Proteas all-rounder Marco Jansen.
England white-ball head coach Brendon McCullum wants his team to play "high-octane" and a "robust" style of cricket as he returns to Australia following the Ashes calamity.
England white-ball Brendon McCullum has hailed Harry Brook as "one of the best tactical captains I've ever come across" even though his team has only won one game in the ODI tri-series in Pakistan.
