"The physical challenge of driving an F1 car is easy for me now," says Button, the 2009 World Champion. "I work very hard on my fitness and I'm fitter now than I was last year, and much fitter than I was five years ago. I can drive 100 laps in any conditions and not have any problems."
Jenson's impressive physical condition can be attributed to two things: his fitness programme and his diet. He works out for up to five hours per day when he's not at a racetrack and he follows a low-carb diet that has been tailored to his sport's needs.
To keep his competitive instincts razor-sharp, he competes regularly in triathlons (swimming, cycling and running). After the season-opening Australian Grand Prix he contested a triathlon in Hawaii and he's maintained a strict nutritional programme.
"I work out a lot," says Jenson. "I need to be fit to do my job and a fit body results in a fit mind. However, I've benefited almost as much through improving my diet. It's a cliché, but we are what we eat and I've worked hard with a nutritionist to ensure that I'm eating the right things at the right time of day.
"I've lost three percent body fat by not eating carbohydrates for breakfast. No cereal or toast for Jenson Button! The benefits of eating the right things are huge; it's something that I underestimated until quite recently."
The only potential snag during Sunday's 56-lap Malaysian Grand Prix is the water bottle that Jenson will have strapped into the cockpit of his McLaren MP4-26. Even with his newfound levels of fitness, he'll struggle in the race without a water bottle because he'll be performing in cockpit temperatures of more than 50 degrees.
"It doesn't matter how fit you are," says Jenson. "If you get dehydrated, your physical performance drops off and your concentration is affected. A couple of years ago my water bottle stopped working on lap two at Sepang and by the end of the race I was suffering a lot.
"The first thing that happened was that I got cold. Despite the excruciating heat I was shivering in the cockpit, which is a crazy thought. My eyesight then started to go and by the end of the race some things became blurred. That's a horrible thing to happen in a racing car! As long as my water bottle works on Sunday, I'll be fine."
Given the impressive performance of his Vodafone McLaren Mercedes MP4-26 at the season-opening Australian Grand Prix, Jenson expects to be competitive at Sepang as well. The team introduced a new front wing, a new floor and a new exhaust system in Melbourne and the combined effect transformed the handling of his car.
"We had a difficult time in winter testing," says Jenson, "but the team did a fantastic job to turn things around in time for the first race. Had I not been given a drive-through penalty, I think I could have finished on the podium at Albert Park.
"Sepang was the scene of my first podium in 2003. I've always loved it and my goal is to finish on the podium again this weekend. This is going to be a long championship, spread over nine months and 19 races, but we saw last year that every point matters at the end of the season."
