London: The thought of next week's season-opening Australian Grand Prix helped Jenson Button push his body through the pain barrier as he prepared for a new Formula One challenge as McLaren's leader on the track.
The aim remains the same but the landscape has changed. Lewis Hamilton has moved to Mercedes, Mexican hotshot Sergio 'Checo' Perez has taken the 2008 world champion's place and Button has his best chance yet of adding a second title to the one he won with Brawn GP in 2009.
Now the most experienced driver on the starting grid, having made his debut in 2000, the 33-year-old Briton has made sure he is fitter than ever as he seeks to win in Melbourne for the fourth time in five years.
"You do put in the extra bit of effort through the winter and because I've been training for so many years now, it does all add up," he told Reuters on a recent visit to the McLaren factory.
"The amount of hours that I do now I wouldn't have been able to do four years ago. Physically it would have been too demanding on the body. My body is used to it now so you can put more time into it.
"But it's not just about the physical training over the winter, its about the mental training and putting yourself through all sorts."
Button - looking 'chiselled' in the words of McLaren managing director Jonathan Neale - said a half marathon he ran in Cannes on the French Riviera on a freezing day in February had been one of the most painful things he had ever done but the rewards would come on the racetrack.
"The way that I got to the end of it was to think about the first race of the season, being prepared for that first race and being mentally prepared, not feeling the pressure, feeling comfortable within myself and within the team," he said.
"That's what keeps you going and I think when I got to the end of the race the strength that I'd gained through doing that exercise mentally and physically will help so much when I arrive at the first race."
When Button joined McLaren at the end of 2009, there were plenty who said he had made the wrong move and was stepping into a 'Lions' Den' where Hamilton was seen as the favourite son.
Over their three years together, Button ended up out-scoring Hamilton. Hamilton was usually quicker, particularly in qualifying, but Button was often smarter in the race.
The boot is now on the other foot, with Button very much at home as the incumbent while 23-year-old Perez must learn the ropes and show that he deserves to be in what should be one of the best cars on the grid.
Button, whose smooth driving skills and intelligence have won new admirers since he joined McLaren, will be looking to lay down an early marker against a team mate who has said repeatedly that he is aiming for the championship right from the start.
McLaren, who have always spoken of their drivers as equal number ones, expect him to show that attitude right from the first race and are not paying Perez to settle for any subordinate role.
"Of course when you are racing for McLaren you are expected to win and this is also my target," the Mexican said after his final day of pre-season testing in Barcelona.
"Sure, there is the need to prove myself but it is motivation rather than pressure that keeps me going. All the other guys that are in a top team have already proven themselves, this is something that I still have ahead of me."
Former McLaren driver John Watson, mindful of Hamilton's sensational 2007 debut when he ended the season second overall and ahead of double world champion team mate Fernando Alonso, said Button could have quite a challenge on his hands.
"Jenson now is the de facto number one driver in the team," he told Reuters.
"But as the senior driver and incumbent, he will have to now carry more responsibility than he would have done when he had Lewis as a partner.
"I thought Lewis was going to be dominant and he wasn't. But that was Jenson joining Lewis. Now Jenson has got Perez. It's never easy when you get a hot rod coming in, and Perez is a hot rod. How hot a rod he is we don't know yet."
The new McLaren MP4-28 was quick at times in testing but Button also felt the team was struggling to get the most out of what was a new design rather than a simple evolution.
The Briton, who won the first and last races of last season, was confident however that McLaren would benefit over the course of the championship.
"We wanted to build a car that would be strong throughout the year and that's why we've made so many changes to the way the car looks, the suspension geometry and how that affects the aerodynamics of the car among other things," he said.
"It's a very long season and we want to be able to develop all the way through the year. And whereas some teams might come with a car that they used in Brazil with a few tweaks to it, which means they will be strong at the first race, they won't be able to develop like us through the year.
"So that is the idea that we have but still we want to be quick at the first race, we want to win from the word go. It's possibly going to be a tough race for everyone because it seems so close at the moment. But we still go to Melbourne aiming for a victory."