Justin Marks embarked on a quest earlier this month that could compare to Formula One driver Fernando Alonso competing in the Rolex 24 At Daytona in order to prepare for Le Mans -- a trip that is part of a training plan with an eye on the future.

Except Marks immediately found one big difference.

"His was probably a lot less painful," Marks quipped Friday at Daytona International Speedway.

Less than two weeks before competing in the Rolex 24, Marks attempted to climb to the peak of Aconcagua, the highest point in the Andes Mountains and the highest point outside of Asia.

Marks spent six days on the mountain, climbing to 21,900 feet, about 900 feet short of the peak.

"It was big," Marks said. "We didn't make it to the top, but we made it really close. ... It was an altitude test for me. Even where we turned around, I was at the highest point in the world outside of Asia."

The climb of Aconcagua was in preparation of a bigger goal for Marks: climbing Mount Everest.

This was it, near our turnaround point. Made it to within 900 vertical feet of Aconcagua's (22,840') summit. We were lucky to get off the mountain before the weather came in. Others were not. pic.twitter.com/sb5CY6PAZ0 — Justin Marks (@JustinMarksDG) January 16, 2018

Thanks everyone for your support and enthusiastic follow.



"The mountains are calling. And I must go" pic.twitter.com/jTEsEE7no0 — Justin Marks (@JustinMarksDG) January 16, 2018

Marks, who won the 2016 Xfinity Series race at Mid-Ohio driving for Chip Ganassi Racing and who has plans to compete in the 2018 Daytona 500, said there came a point during his climb that his resting heart rate was the same as his physical heart rate and he couldn't recover.

"The hardest part of it is pushing yourself to your absolute limit, finding what your absolute limit is," the 36-year-old Marks said. "It was incredibly painful and it was uncomfortable, but knowing you got yourself to the absolute limit, that's awesome."

It would seem that turning around about 900 feet from the peak would rank as the most difficult part of the journey. For Marks, though, he had already accomplished much of his goal.

"It was a combination of kind of getting my butt kicked a little bit -- I was suffering -- and we had weather coming in and so we just made the decision to turn around," he said. "I was a little bit nervous that if I pushed all the way through to the top, I wouldn't have the strength to get down well."

There were some cool moments, including the international flair of the base camp, where Marks said he met a Tibetan mountain-climbing group as well as a group from France.

So it was fun. Most of the time.

"Part of mountaineering is figuring out how to endure through struggle and suffering," Marks said. "There are not a lot of people up there that are just bouncing around, smiling, having a great time. That's kind of the price you pay for going to the places that are really rarely traveled by a human.

"So, it had its struggles, but 95 percent of it was totally fun. This was about learning, how to just exist at high altitudes -- how to camp, how to cook, how to move around the mountain, all that kind of stuff."