Leigh Halfpenny helped Wales reach the summit of rugby union's world rankings just hours after a punishing training session in an altitude room.
Halfpenny returned to Test rugby in Wales' 13-6 World Cup warm-up victory over England at the Principality Stadium.
It was the Scarlets full-back's first international appearance since he suffered concussion after a challenge by Wallabies centre Samu Kerevi when Wales beat Australia nine months ago.
But it proved an unexpected call-up, being drafted in to start from outside the selected match-day 23 when Liam Williams experienced hamstring tightness during Wales' final preparations less than an hour before kick-off.
Having initially not been required against England, Halfpenny's training schedule featured gruelling work-outs on Friday and Saturday before he joined pre-match routines at the stadium as part of Wales' wider 31-man group.
Halfpenny, though, dusted himself down, played the full 80 minutes and kicked a late penalty that sealed Wales' 11th successive home win and saw them replace New Zealand as the world's number one team.
"I'm not going to lie – we had a couple of tough sessions in the last couple of days," Halfpenny said.
"But you get the call, and that adrenaline just kicks in. It's an opportunity to put that jersey on.
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"On Friday, we had speed endurance training. We did Broncos, which are basically shuttles, and the boys put it in on Friday after the captain's run.
"Then on Saturday morning I had leg weights followed by a watt bike session in the altitude room. (I) wasn't walking too well, I will be honest."
Halfpenny had missed Wales' last eight Tests, including the Six Nations title and Grand Slam-winning campaign earlier this year, but he acquitted himself well during an intense encounter.
"You never know when it could be the last time that you wear that jersey," he added. "You just keep working hard.
"It was a real tough Test match, and the boys dug deep at times when we needed to. It was a great result.
"We've got that momentum going now ahead of our (training) camp in Turkey. The boys will be putting the hard work in again."
Wales' World Cup training squad will work at the purpose-built Gloria Sports Arena in Belek on Turkey's southern Mediterranean coast, where day-time temperatures currently average 33 degrees.
Players who suffered knocks against England – the likes of Dan Biggar, James Davies, Jake Ball, Aaron Wainwright and Gareth Davies – were set to be assessed before departure, but Wales head coach Warren Gatland does not anticipate any serious issues.
Reflecting on his team's latest win – their 15th from the last 16 starts – Gatland said: "You're playing England, so you have to get yourself right.
"The boys knew how important it was, psychologically. Had we lost to England, that potentially has an impact later on if we met them in the World Cup.
"It will be one hell of a battle if we do meet in the quarter-final of a World Cup.
"So mentally, they got themselves on the edge. They prepared well and did a good job."