It can be hard to be favourites. 

The weight of expectation can hang far heavier and less comfortably than a gold medal ever could.

But there was never much doubt about this one.

Australia has once again asserted its dominance over the 4x200m relay, reclaiming a title it has won just once before despite being almost unbackable favourites.

This was almost business like in its execution. No frills. No thrills. No surprises.

The Aussies were projected to be almost seven seconds faster than their nearest rivals on paper and won their heat by 6.62 seconds on Thursday morning.

As ever, the theory did not match the reality, but it was, nevertheless, another emphatic display from the Aussies, a fitting show of the extraordinary depth of Australian women's swimming in the country.

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That is a depth led, of course, by the two fastest women in the history of the event: Ariarne Titmus and Mollie O'Callaghan.

Complicated adversaries on Tuesday, this morning they were teammates in more than just name.

This was a performance that was both about them and not, a victory for the whole, spearheaded by Australia's two best individuals.

And not just Australia's best. The world's best, who between them hold nine of the 11 fastest times in history.

It is their lead that Australia has followed and followed well — over the past 12 months, seven Australians can be counted among the fastest 20 women in this event.

Canada, China and the USA can count two swimmers each in that same group.

Not that the latter of those two teams didn't push Australia all the way.

Led off by O'Callaghan, the individual gold medallist from earlier in the Games, Australia had the perfect starter.

Her time of 1:53.52 was slower than her gold medal winning performance of 1:53.27, but fast enough to hand over to Pallister with a decent lead.

Pallister, despite her recent bout of COVID, clocked 1:55.61, but China was lurking as a genuine threat, hovering within a second of the Aussies in lane three.

Throssell was next in, and she suddenly had to deal with a charging Katie Ledecky as well.

Ledecky didn't swim the individual despite winning the American trials, but she was flying here and pulled the Americans into second place.

But handing over to the world record holder is not a bad way to finish things off.

And she made no mistake, powering away down the final leg to claim victory in 7:38.08, just outside the world record.

It is the first time since 2008 that Australia has won the 4x200m relay after the surprise bronze in Tokyo.

"I was disappointed with how I swam in Tokyo, I personally felt I let the team down," Titmus said.

"This was a personal vendetta for me to come back and play my role in team, but do it for our country. 

"This was a gold medal that we knew could be ours."

Although a dominant team performance, the very nature of swimming is its individualism.

It is, so often, a very solitary pursuit.

Swimmers are forced into the silence and isolation provided by water, leaving them alone with only their thoughts and the bottom of the pool.

Relays offer a glorious chance to celebrate together as one, but there are so many individual storylines to embrace as well.

And all of these Aussies have stories to tell.

Take Pallister, a casualty of COVID that ruled her out of Wednesday night's 1,500m but is now back to take an important role in this team and earn an Olympic gold in her first Games.

"I didn't think I'd be part of this relay at the start of the week," Pallister told Channel 9.

"So to be here standing with them, I don't think I could ask for anything more from my Olympic experience."

The journey she has taken to get to this point is one rockier than most, overcoming an eating disorder that threatened more than just her competitive career.

Throssell, who was embraced by Titmus after the race, collects her fourth Olympic medal and second gold to sit alongside the two bronzes.

They were all as a heat swimmer though, adding to the emotion that flooded in the tears down her face.

"Bri and I have been roomies for three months and she has never stood on the Olympic podium before," Titmus told Nine.

"It was very special to have her next to me singing the national anthem."

Then there are the heat swimmers. 

For Jamie Perkins, that was her first Olympic gold medal — O'Callaghan draped hers around her neck during the victory lap. And why not? She already has two from this Games.

"Jamie is my best friend at training," O'Callaghan said.

"She's there for me. She's been my roommate this whole meet. She has trained her arse off to get here. She's gone through a back injury, done everything possible. 

"I think that gold medal means a lot for me to give to her because it represents what she's been through and she's well deserving of it."