Seven-time Formula One world champion Lewis Hamilton said on Thursday he had spent the summer break training not partying, in the best shape of his life as he chases another title.
The 41-year-old sits 50 points behind current championship leader Kimi Antonelli but said his Ferrari was in a "sweet spot" that gave him hope of being able to close the gap.
"This has been the most different summer break that I've ever had in all of my championship seasons," the veteran Briton told reporters.
Previous summer breaks involved a week or two off "with a bit of partying and stuff," he said.
But this year was different. "I took this as an opportunity to really level up. So I trained for three weeks."
"I come back the fittest I've ever come back in summer in the 20 years or whatever that I've been here," he said in an ominous warning to his rivals.
Hamilton cut a very different figure to the man who arrived at Zandvoort last year.
Following a frustrating start to his career at Ferrari, he had suggested the team should find another driver and that he was "useless".
One year on, he said what had changed his outlook was that the team was moving in the right direction and the changes he had demanded had been implemented.
"I think we're in a real sweet spot. We're just going to continue to build on this foundation that we've built," he said.
Further driving Hamilton on is the fact he has never won at Zandvoort in his long F1 career.
This will be his last chance, as the Dutch Grand Prix is being removed from the calendar after this season.
"I've won at pretty much all the other tracks... So I definitely want to change that. So massively driven, it's just such an incredible circuit," he told reporters.