Ireland will emerge from a six month break as a new and improved force, says lock Aoife McDermott.
Adam Griggs' squad have held 20 training camps since their most recent game; against Italy on 24 October.
They return on Saturday against Wales, who are coming off a heavy defeat by France in their Six Nations opener.
"We're the fittest, strongest, fastest we've ever been, I think we've come a long way in the last 12 months," said McDermott.
"I really believe we've improved a huge amount over the last 12 months, albeit having not played in a game.
"We're in one of the best places we've ever been and I think we can go out and cause upsets this tournament.
"We're going into this campaign to win every game. I'm up for the challenge of it, we all are."
Having missed the game in October with a fractured foot, McDermott has not played a Test match since February 2020.
However the Leinster lock says that the lack of match practice will not hinder Ireland's performance at Cardiff Arms Park, where they aim to put the strides they have taken in camp into the Test arena.
"We've certainly had a lot more time than ever together... with that we had the ability to refine our set-piece and our attack," she said.
"I think you'll see some new stuff from us come Saturday night, our set-piece is in a very strong place, our defence is very fluid and everybody knows their role incredibly well.
"We've never had so much clarity and understanding of what's expected of each individual and what our role is heading on the pitch."
'Extra week's preparation can work in our favour'
Wales were thrashed 53-0 by a rampant France in last Saturday's opener, and will be looking to bounce back on home soil.
The new format, introduced in response to the pandemic, which has seen the teams initially split into two mini-groups of three, meant that Ireland did not have a game on the first weekend.
"We've had an opportunity to analyse them and stop some of their threats, whereas they haven't seen us play in a while so hopefully we'll be able to catch them on the hop," said McDermott.
"For me, from a line-out point of view, see what they're up to at the line-out and hopefully disrupt that as much as we can on Saturday.
"In ways you could tell that they hadn't played a game in so long. They were probably a little bit no sharp or as tuned in as France have been, but I don't expect the same scenario this weekend.
"They have that game under their belt, they're going to come probably a bit battered and bruised and hungry to right the wrongs of last week."
With semi-professional France heavily fancied to top Pool B, victory on Saturday for Ireland would ensure they avoided a bottom-place finish in Pool B, with a game against France to come on 17 April.
After the two group matches, each team will play their equivalent in the other pool to decide final positions.