INDIANAPOLIS – On Sunday, Kyle Larson will lower himself into an IndyCar to race for the first time in his life and will drive for three hours.

A couple hours after that, he'll do it all again in another state.

NASCAR Cup's current points leader is attempting what racers call "the Double," by racing the Indianapolis 500 and NASCAR's Coca-Cola 600 on the same day. If he's able to complete both, he'll race 1,100 miles in a car while traveling more than 400 miles by plane to do it.

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But although he will make the 11th attempt all-time at this ultimate endurance test, only one driver to date has actually hit all 1,100 miles. That was Columbus, Indiana, native Tony Stewart, who pulled it off in 2001.

For more than three weeks prior to that 2001 race day, Stewart worked with a trainer from the Carolina Panthers to retool his diet and workout routine to handle the grueling conditions. He'd found it necessary after his first attempt in 1999 covered 196 laps in a Indy 500 ninth-place finish, after which he felt signs of hallucination.

With 20 laps to go in the Coca-Cola 600 in Charlotte, a hotdog wrapper blew across the track, but he swears he saw something different.

"I thought it was a ginormous pink elephant with polka dots on it," Stewart said in a video interview provided by his marketing team.

This was hunger, fatigue, stress and adrenaline swirling into one delusion while trapped in a speeding car.

By 1999, Stewart was a NASCAR Cup rookie but had driven the Indy 500 multiple times. He grew up around this race and thought he knew what it would entail.

“I remember how bad I felt about 100 laps into the 400 laps in Charlotte," Stewart said. "We were probably 150 miles into the race and I realized I was hungry, and it’s not like you can stop and pull through a drive-thru and get a sandwich, some fries and a Coke and go on down the road.

"That was just one of the many variables that I didn’t know going into it and didn’t think about. I was so focused on just driving the race cars.”

The list of variables is long, and it has evolved over the 30 years since John Andretti made the first attempt, when he finished 10th in the 500 and 36th in the 600.

Some parts are easier, such as the flight schedule between the cities in the 10 days leading up to the races. Drivers used to have to bounce from NASCAR qualifying races on Thursday, to Indy 500 Carb Day 500 on Friday, to NASCAR practice on Saturday, then back to Indianapolis to race the 500 on Sunday. Now, NASCAR consolidates its pre-race events to Saturday.

Drivers also used to have to make it to the 600 in time for the pre-race drivers meeting or risk starting at the back of the grid. Since the pandemic, drivers can handle those briefings virtually.

Other parts are not quite so easy as they were for Robby Gordon, who joins Stewart as the only racer to have made multiple attempts. Gordon made five of them (1997, 2000, 'and '02-04) and built a routine that cut down on the chaos at a time when the Indianapolis 500 started more than an hour before it does now.

“(Larson) has lost that margin of where we’d get there an hour or maybe 45 minutes before the green in Charlotte," Gordon said. "He has to have a perfect event to pull off the start of both events."

That doesn't always happen, of course. Gordon's attempt in 2000 ran into a three-hour rain delay in the 500, forcing a backup to start the 600 for him before he could arrive in Charlotte and swap in during a pit stop, resulting in a 35th-place finish.

Last year, the 500 saw three crashes result in red flags. Each crash can take a toll on a day where time feels like money to a driver like Larson, who is risking his Cup points lead, a championship he's trying to win for the second time in four years.

As the business of racing has grown, so have the corporate demands on the drivers and their teams, which only tighten the constraints on trying to compete for two teams at once. That's what Larson will attempt as he drives for Arrow McLaren in the 500 and his normal Hendrick Motorsports team in the 600.

Back when Stewart made his 2001 attempt, Chip Ganassi organized a conference call between the CEOs of Home Depot, which was Stewart's NASCAR sponsor; and Target, which was Ganassi's. He pitched them on an idea that had the potential to make the competing executives' skins crawl: having Stewart drive a car for Home Depot and Target together.

"It was just the idea that we were going to collectively do this and win the race. Home Depot and Target together with Tony Stewart were going to win this race," Chip Ganassi managing director Mike Hull said.

"You have to convince the partners that it's a good idea. The partners all have to do what they have to do with their accountability in order to get full buy-in: How many store visits are you going to do? What uniform is he going to have on? What color shirt are the crew members going to have? Where are the decals going to be?

"You have all these other logistical mechanisms that are going on that feed the racing, and then you have a group of guys like me where, frankly, all we care about is racing cars. That's why we do this. We want to race to win the race."

Between those corporate negotiations, the travel constraints, the team demands, the injury risk and the preparation time, attempts at driving both races have dwindled in a way that makes Larson an outlier.

Between 1994-2004, eight "Double" attempts took place. But in the 20 years since, only one driver has made an attempt, Kurt Busch in 2014.

Busch finished sixth in the 500 but fell to 40th in the 600, after starting at the back of the field due to missing the pre-race drivers meeting. His sixth-place finish in the 500 tied Stewart and Gordon for the best by a driver attempting to do both races in the same day.

“I was super impressed with Kurt and what he did at the Double," Stewart said. "To not have any IndyCar background, that’s tough to get in those cars and get up to speed. It’s one thing to drive them and drive it by yourself. But to drive in traffic and understand how to get momentum and runs on other cars, that’s really hard to learn in a short amount of time and that’s something that the veterans are so good at."

The year before Busch's attempt, Larson did "the Double" as a fan. He attended the Indy 500 and then flew to Charlotte for the Coca-Cola 600. He was only 21 then, but he dreamed of eventually hitting his prime and becoming the latest driver to attempt the feat.

Nobody has tried it in the 10 years that have passed since Busch's attempt. For years now, Larson has spoken about his desire to do it to fellow drivers, and now, he's going to put those dreams into motion.

A grueling day awaits.

“We all know," Gordon said, "he’s not scared.”

Contact Nate Atkins at natkins@indystar.com. Follow him on Twitter @NateAtkins_.

This article originally appeared on Indianapolis Star: Kyle Larson tries to complete the Indy 500-NASCAR 'Double'