Johnny Sexton says he is back to full fitness following injuries and a Covid-19 infection.
The Ireland captain damaged his knee and ankle during last November's win over New Zealand and then had to cope with a Covid-19 infection.
However, he has since made a full recovery and played for Leinster twice over the last 10 days in Champions Cup wins over Montpellier and Bath.
"My body is OK, I had a frustrating couple of months, post the New Zealand game," he said at the launch of the Guinness Six Nations.
"Injuries, managed to pick up Covid as well so that knocked me for 10 days to two weeks so it was not an ideal prep.
"But thankfully over the last few weeks I was able to step up in training and get back on the field unscathed.
"Look, it was at the end. I was back from the knee injury ready to go and then obviously picked [Covid] up and was sick for a week or so with it.
"Then obviously it takes a little bit longer time to get back fully fit, a couple of games were cancelled.
"Obviously, the first game back was a European game so I blew the lungs out on that.
"It was a shock to the system but I felt much better last week and hopefully now we'll train hard this week and it will be another good step in my preparation.
"I know I need to train well to earn my place in the team and that’s more my focus is getting as fit and ready as possible to challenge for that spot."
The 36-year-old, who will win his 102nd Ireland cap if selected for the 5 February meeting with Wales in Dublin, said the team wants to build on a successful autumn series, which also included wins over Japan and Argentina.
"We’ve got a pretty young squad apart from one or two outstanding outliers like myself," he said with a smile, "but the guys bring great energy when they get in.
"It’s a great camp to be a part of over the last couple of years and especially in November when we put things together and we put in some better performances that we had done previously.
"We hope to continue on that line leading up to the Six Nations. We are playing the reigning champions at home first up and all our focus is on that at the moment."
It became the norm playing in empty stadiums over the last 18 months and to get them back in November was incredible
The former Racing 92 and Lions out-half added that having spectators back after almost two years with restrictions adds an extra buzz to the tournament.
"It became the norm playing in empty stadiums over the last 18 months and to get them back in November was incredible," he said.
"It really lifted the players' performance and gave guys a first taste of playing in front of family and friends because a lot of guys got their first caps playing in an empty stadium.
"Then there were worries we’d go back to empty stadiums for the Six Nations but thankfully the restrictions have lifted here, the same in the UK, which is the way the Six Nations should be.
"It’s the way that rugby should be played and we are really grateful for that. We’re looking forward to it now."
While the fans will flock back to the stadia, Sexton said he expects that there will still be restrictions on squad activity.
"It's great to have the crowd back but I still think we are a little bit away from normality as such, from an internal side of things," he told RTÉ Sport.
"We are still restricted by the competition bubble, which is understandable. Hopefully as the tournament goes on we’ll see how things go.
"For the moment, we’re under tournament restrictions."
Follow all of Ireland's Six Nations games via our live blogs on rte.ie/sport and on the RTÉ News App or listen to live radio coverage on RTÉ Radio 1. Watch live TV coverage of Ireland v Wales (5 February, 2.15pm) and England v Ireland (12 March, 4.45pm) on RTÉ2 and the RTÉ Player.