2007 world champion Kimi Raikkonen admits he often used to race motorbikes - without his Formula 1 teams knowing.
The Finn, now retired, raced for top teams including McLaren and Ferrari, and he now operates a highly successful motocross team with Kawasaki support.
"I have always appreciated the challenges that motocross has for you as well as the very physical side," Raikkonen, 43, is quoted by RTBF.
"Sometimes I went riding in small club races but it was just for fun," he said. "It wasn’t at a high level and I felt that it was part of my fitness program.
"I don’t know what any of my teams thought about it as I never mentioned it to them," Raikkonen smiled.