Imagine being strapped to a wall standing straight up so only the balls of your feet touch the floor. Then, someone wraps a belt around the back of your head and pulls it as hard as possible while you try to stop your head from moving forward.
As you try to keep your head up, you also must hold two bricks out in front of your body and twist them up and down in a circular motion when the belt gets pulled.
Had enough yet? Well, that's not all.
In addition to the belt and the bricks, python-like pressure is applied to your torso, squeezing the air from your lungs and making it impossible to breathe. The constriction also squishes your internal organs against your rib cage.
The pressure means you must also hold your breath to help keep your lungs inflated and tighten every muscle in your core to stop your insides from being tenderized.
Lastly, someone also pushes your legs hard on the side as the belt is pulled and you must keep the balls of your feet planted firmly on the ground.
That's about what an IndyCar driver experiences in just one turn.
Now try to do this 11 times every 60 seconds or so for about two hours. Once you can do it for two hours without fail, you just might be ready to drive an IndyCar around Toronto's 11-corner, 2.824-kilometre Exhibition Place street circuit.
Even though this scenario sounds exhausting, it's amazing to think that many people simply don't believe that race drivers are athletes.
"You hear it so much and we all have heard it for years – I mean people don't even appreciate how physical a go-kart is – the forces that are put on our bodies are similar to that of fighter pilots," said IndyCar driver James Hinchcliffe, who has a series-high three wins this year.
"It's not like hockey where you do a two-minute shift and then sit for five minutes or like football where you are flat out for 10 seconds and then rest for minute. It literally is twice the length of a soccer match, but your heart rate is going higher and you're using a lot more muscle in your body – they are just obviously using their legs and their lungs – we are using an incredible amount of upper body, an incredible amount of core, neck, it really takes every muscle group in the body to successfully drive a race car."
Even some fellow athletes don't believe it. Many might recall how Major League Baseball player Larry Walker quipped that he had lost to a car when 1997 Formula One world champion Jacques Villeneuve took home that year's Lou Marsh Award as Canada's top athlete.
Once you get past the idea of a baseball player – who shared the field with many physical specimens more closely resembling Norm from Cheers than finely-chiseled athletes – scoffing at racing drivers' fitness levels, there's also science to back it up Hinchcliffe's contention.
Dr. Stephen Olvey, an associate professor of Clinical Neurology and Neursurgery at the University of Miami, led a study a decade ago which debunked the idea that racing drivers are not athletes.
The founding fellow of the Fédération Internationale de l'Automobile Institute for Motorsports Safety recorded the oxygen intake of several drivers during practice sessions on both oval tracks and road courses to measure the physical demands of piloting an IndyCar against other sports.
"We found their oxygen consumption was that of someone who swims competitively in the 1,500 metres or runs in a marathon," said Olvey, who was also medical director for the now-defunct Championship Auto Racing Teams (later Champ Car) for two decades.
"There is no question that drivers are well-trained and very fit athletes. You can't be competitive in IndyCar or Formula One or any of the open-wheel series and not be in peak physical condition."
To get there, most drivers train for several hours daily, combining aerobic and anaerobic exercise to develop the endurance and strength needed to withstand the rigours of racing.
Drivers also have several workout routines geared specifically toward strengthening their necks, which must withstand enormous strain and pounding during races.
"Fitness for me is one of the most important things," said Bruno Spengler, of St. Hippolyte, Que., the reigning Deutsche Tourenwagen Masters champion.
"I spend a lot of time on it because, first of all, I feel good when I do it, and second, I always say to myself that in the last 10 laps of a race, you are a fitter driver that the guy in front of you, then maybe there will be a bigger chance he will make a mistake when you put the pressure on."
On average, BMW driver Spengler trains three hours per day, five times a week. He also plays several sports to help him with different aspects of his mental and physical fitness. He runs and bikes for cardio, plays golf for the concentration, tennis for hand-eye co-ordination and, in winter, he tries his hand at biathlon, which helps all three.
Racing also requires mental fitness and a constant level of intense focus because a car moving at 320 km/h travels about the length of a football field every second – so you can't have any lapses or the car may end up jammed under a tire barrier.
That's why drivers also have routines to help them hone their reaction times, especially when fatigue sets in.
Hinchcliffe has a regular mental fitness test in which he starts with a few quick laps in a racing simulator before working out for an hour or two. When he's done training, he gets back in the simulator and won't leave until he matches the lap times from when he was fresh.
Staying fresh was a huge concern for DTM driver Robert Wickens, of Guelph, Ont., when he moved into the German touring car series last year. Until he signed to race for Mercedes in DTM, Wickens had only driven open-wheel cars, which have generous airflow over the driver.
With the closed cockpit, DTM cars often heat up to 60 C during races. The biggest adjustments for Wickens were the temperatures and oxygen-depletion, because of the mostly stagnant air inside his car. So he came up with a novel way to beat the heat and stay focused.
"I changed my training to spend more time in the sauna and doing heat tank training where I basically put my bike in a heat chamber and do that training in a hot room," Wickens said.
"You have to be well over-fit of what you are driving to have the concentration that you need – you can never be thinking, 'Oh man, I am getting tired,' because as soon as you start thinking about something that's not driving, you start making mistakes and losing lap time."
Unlike most sports, drivers get precious little time in their element compared to most other athletes, which means proper preparation is king.
For example, if you add the number of hours a race driver is in the cockpit over a year compared to the amount of time a National Hockey League player is on the ice, it's a miniscule fraction of the skater's total. An IndyCar driver will spend roughly 150 total hours in the car through a season, including some limited testing. Most NHL players surpass that in ice time in a matter of weeks.
"There is nothing that can truly recreate the forces that you experience in the car, so you have to do the absolutely best job you can preparing in the gym and, to do that, you need to be in there every day training for the amount of time that your body is going to be under stress in a race," said Hinchcliffe, who drives the Go Daddy car for Andretti Autosport.
"You need to have a pretty good excuse for yourself to miss a day in the gym because we know how important it is to continuously try to keep up that level of fitness."
Anyone who really wants to understand how tough racing is, physically and mentally, should head to their local go-kart track to drive them as fast as they can for as long as they can.
It may look easy, but Hinchcliffe thinks few would be able to keep the pace for long.
"If they go do 20 minutes straight at a good indoor go-kart place, they are going to be absolutely wrecked," Hinchcliffe said.
"Their ribs are going to hurt, their hips are going to hurt, and their forearms will be locked solid with arm pump. It's just one of those things that until you do it and experience it, it is really tough to appreciate it."
And drivers need to be incredible fit to combat the gravitational forces they experience in the cockpit.
For example, in June's Canadian Grand Prix, Formula One drivers experienced more than 4.5 times the pull of gravity during deceleration for six separate corners, according to brake manufacturer Brembo. At the end of the long straight before the start-finish line where the cars slow from 320 km/h to 135 km/h to negotiate the upcoming chicane, maximum deceleration hits 5.98Gs, which would make the driver's head and helmet feel like it weighed more than 30 kilograms.
Although Montreal's configuration is tougher when it comes to accelerating and braking, there are several corners in an F1 season that put the drivers through heavy lateral G-forces, such as the 5Gs in Silverstone's Copse during the British Grand Prix and the Curva Du Laranjinha at Brazil's Interlagos Circuit. Seven other tracks on the F1 circuit feature corners with lateral loads on the driver of four times gravity or higher.
The Olvey research measured IndyCar drivers' metabolic rates, or mets, which are 13 to 14 when at speed in their cars. A person's "met" is one when they are at rest.
"When people say they aren't athletes, I know they don't really understand motorsports," Olvey said. "People who are into motorsport and understand it realize that drivers at the high levels of professional motorsports are top-of-the-line athletes – people who don't understand that and think they're just driving like they drive to work really are naive and don't have any inkling of what it takes to drive a high-speed racing car."
And when things go horribly wrong, the high fitness levels become critical.
Olvey offered the case of Alex Zanardi, whose physical conditioning literally saved his life.
In 2001, Zanardi lost both legs when his racer was cut in half by another car in a devastating crash at the EuroSpeedway in Germany. The Italian lost almost all of the blood in his body but survived, despite the medical evidence insisting he probably should have died.
"He lost over three-fourths of his blood volume in a very short time and there's no way an individual can tolerate that unless they are in extremely fit condition," said Olvey, who was on the scene of Zanardi's accident. "It helps as far as injury prevention and does keep the severity of the injuries at a minimum."
In Toronto, drivers will hit a top speed of about 280 km/h on the long Lake Shore Boulevard straight, before braking to about 60 km/h in about 145 metres to negotiate the tight right-hand Turn 3. Under peak stopping power for the corner, drivers will experience a maximum of about 3.4Gs, mostly because they cannot slow the car as fast as possible due to the bumps in the braking zone.
In the final corner of the street circuit at Sao Paulo, Brazil, where Hinchcliffe made a last-gasp pass on rival Takuma Sato for his second win of 2013, IndyCar drivers experience about 4.5Gs under braking, which is the highest of the season.
The cardiovascular system also experiences huge amounts of stress during races, but again, the drivers' fitness levels ensure it's tolerable.
An IndyCar driver's heart rate will usually be somewhere between 150 and 165 beats per minute when at speed, similar to that of a competitive marathon runner. Interestingly, if a full-course caution comes out, a driver's heart rate drops to normal almost immediately because their training allows them to respond to the environment instantly.
A normal heartbeat is somewhere between 60 to 100 beats per minute, which increases during physical activity. But because race drivers are in such good shape, their hearts are more efficient and can use a lower heart rate to meet the metabolic demands of the task at hand.
"If you were to put a normal individual who is not necessarily an athlete and put them under the same stress that a driver has in a racing car, their heart rate would go very high and they wouldn't be able to sustain it," Olvey said.
"They would have to give up – depending on their age, their heart rates would probably approach 190 beats per minute and it wouldn't be sustainable."
But none of that means drivers don't get tired after completing their work on a Sunday afternoon.
Street courses like Toronto can be especially tough, beating up drivers with their bumps. Racers often emerge from the cockpit with bloody elbows and knees and huge blisters on their hands.
And even though all IndyCar drivers will probably be spent after two full races on the streets of Exhibition Place during the doubleheader weekend in Toronto, it wouldn't be the best time to suggest they aren't athletes.
"It's a huge bone of contention with drivers because we do work so hard on the physical element," Hinchcliffe said.
"After a race, you are so exhausted because of what you have been through, and for someone to come and tell you that you are not really an athlete, you kind of just want to slap them across the face and say, 'Oh, you think so? You go try it'."
For more from Jeff Pappone, go to facebook.com/jeffpappone