Waltrip, Petty complete marathon.

NASCAR Nextel Cup stars Michael Waltrip and Kyle Petty stepped up their preparation for the 'marathon' that is the forthcoming season by.... taking part in a marathon of another sort.

The two drivers participated in the Las Vegas marathon at the weekend, and may consider 30+ weekends on the road a holiday in comparison. The event took Petty four hours and 16 minutes to complete, and he admitted that he had rarely done anything so physically tiring.

"Few things in life have I conceded kicked my rear end, and that was one of them" he said, despite having run a half-marathon prior to last year's Las Vegas testing.

Waltrip, who ran Sunday's marathon as part of his ongoing fund-raising effort for the Petty family's Victory Junction Gang camp, finished below the four-hour mark - in three hours, 56 minutes and 26 seconds - beating his previous best time by almost 20 minutes.

"When I ran the half-marathon last year, I did it for Michael because Michael had done it before and I thought it was pretty cool," Petty said, "Last year, when we were out here, I told him I'd come back and do it with him. But it was tough!"