It's an age-old debate, hotly contested by analysts, participants, fans and detractors alike - are the men and women behind the wheels of NASCAR's finely-tuned machines athletes or simply skilled at quickly navigating a left turn?

In 2012, ESPN Sport Science tackled the issue using sensors to monitor the physical impact on drivers during these four-hour marathon events. Reports found temperatures inside the car were upwards of 100 degrees throughout the race with drivers losing a substantial amount of water weight and endure G-forces up to three times greater than a stationary human.

Physical demands seemingly magnified at a pressure-cooker like Bristol Motor Speedway, where prior to the adoption of modern cooling systems, it was common for drivers seeking a breather from the cockpit's blistering heat to turn their rides over to a replacement driver partway through the race.

This week, four-time Bristol winner Carl Edwards offered his opinion during a media stop at Bristol Motor Speedway to promote the March 16 Food City 500.

"There's no 'one hardest thing' about Bristol," said the four-time Bristol winner. "It's a very physical race track, but it's a really interesting mix. You can be the most physical, the toughest guy in the world, but you can't relax at Bristol. There's no human that can hang on and squeeze and tough it out for 500 laps there.

"Bristol's a place that there's always that elevated tension, and you have to learn to make it through that and pace yourself so you can be really intense at the end."

And a driver's first time navigating the high banks can be even more demanding.

"My first time at Bristol was in the truck series," said the driver of the No. 99 Ford Fusion. "I pulled out for practice, and I don't think I breathed the whole time. I was gripping the steering wheel so hard, my hands got all worn out. Thankfully my crew chief, Doug Richert, called me in because I don't think I would've made it another 10 - 12 laps. It's a very intense place."

In order to endure these grueling conditions and sustain a competitive edge 36 Sundays each year, many of the sport's stars commit themselves to rigorous off-track fitness regimens making them not only world-class drivers but world-class athletes as well. Edwards' athletics capabilities were also on display this week at Velocity Sports Performance Bristol as nationally-certified conditioning coaches and East Tennessee State University's Division 1 coaching staff led him through a football-inspired workout.

As Edwards, along with BMS Senior Account Manager and former University of Louisville offensive lineman Graig Hoffman, worked through intense conditioning drills and skirted their passing routes around former Chicago Bears cornerback Teddy Gaines, coaches and trainers alike praised Edwards conditioning and athleticism.

"I could see his athleticism immediately," said ETSU head football coach Carl Torbush. "Physically, he has the build of a defensive back and even a linebacker."

"He performed really well," said Velocity Sports trainer Jason Moreno. "Protecting our athletes is always a priority, so I'm hesitant to put someone I've recently met through some of the more strenuous conditioning exercises, but Carl is in great shape and had no trouble executing the moves."

Sport Science also tested Carl's abilities in this 2011 segment:

To see Carl execute on the Bristol Motor Speedway training ground, reserve your seat inside the Last Great Colosseum today! Tickets for the March 16 Food City 500 start at just $65 with weekend packages available for as low as $99, so call (855) 580-5525 or visit www.bristoltix.com to experience this spring's battle on the high banks.