The Erebus driver was robbed of a second Bathurst crown in heartbreaking fashion on Sunday evening, severe cramping thought to be from dehydration forcing him out of the race during a triple-stint to the flag.

He had been leading the race before the cramping took hold, and tried to make it through the last stint, only for a loss of feeling in his left leg to result in the early release of the clutch during his final stint.

That meant he was given a drive-through penalty, at which point he finally decided to hand the car over to teammate Luke Youlden.

Reflecting on the distressing end to the race, Reynolds confirmed that his first step is to see a doctor to confirm is his suspicions regarding dehydration are correct, or if there's something more sinister at play.

"You psychoanalyse your own performance within an inch of its life," he told Motorsport.com.

"There was nothing wrong with my driving, just something wrong with me. So I need to go to the doctor and figure out what actually happened.

"I think I know what happened, I think I just dehydrated myself. I sweated out everything I had. I'm notoriously bad at drinking while I'm in the car. I never do it, because I've never needed to. I've never felt those signs on dehydration.

"I'll go see someone and be better prepared. That's all I can do. Knowing the signs is the first thing.

"I've never failed physically like that, I've never had anything like that happen in my life. I've never had a cramp running, cycling, racing... it just came out of nowhere."

Reynolds admitted that the exhaustion began as a mental battle, before later becoming physical through the leg cramps.

"I struggled to concentrate," he said. "It got worse. I had tunnel vision, it was all tunnel vision.

"They did a [windscreen] tear-off at the last stop, I thought the screen was dirty. But my vision didn't get any clearer afterwards.

"I put my foot on the clutch during the stop, I put the car in the gear, and my foot was cramping so much. I was telling myself to keep the clutch in, but the wheels must have been spinning.

"To be honest I had no idea."

Reynolds had been complaining of tiredness throughout Bathurst week, and reckon the media-heavy build-up as the reigning winner contributed to the breakdown.

"I've had a massive lead-up to the race, which probably contributed to it. I've spoken to every man and his dog about the race," he said.

"I was probably 70 per cent fit in qualifying, and I woke up 50 per cent on Sunday. And the race took it all out of me. The warning signs were there.

"If you don't like doing media, don't win the Bathurst 1000. But I want to make my sport better, I want more people to watch it, I want it to be the biggest sport, so I always say yes to every interview I'm offered.

"I never knock it back. I've got a good story to tell, it was a great story last year. And we were making a better story, and it all failed...

"I'm f**king gutted. You work your whole career for a fast car at Bathurst. You only come here to win this race.

"I'm not in the fight for the championship, so I don't give a f**k about that. I was here to go back-to-back, and it just didn't happen."