During every NASCAR season, racing fans the world over are beside themselves with pulse-pounding excitement as they watch their favourite drivers compete for riches, glory, and the Nextel Cup. It's also time to renew a debate that has gripped racing enthusiasts for years - should racecar drivers be considered athletes?

Most people don't realize it, but professional racecar driving is a high-stress, physically demanding job. It requires razor-sharp reflexes, heavy-duty muscle power, and incredible endurance. To get race-ready, drivers practise at the racetrack, and they also put in quality time at the gym.

The American College of Sports Medicine says that during competition on a road course (which involves a lot of changes in direction, velocity, and road surface), professional racecar drivers demonstrate physiological responses similar to those of elite athletes playing team sports. Researchers from the University of Miami found that drivers use as much energy as their counterparts in basketball and football. The average oxygen consumed while racing was up to 13 times that of resting consumption levels, and drivers' heart rates were about 76% of the maximum (70% to 85% is the range for high-intensity exercise).

There is a race nearly every week and drivers must contend with fatigue, as the schedule is gruelling and the races can be several hours long. Their ears are assaulted by noise from their cars and the racetrack. Extreme heat is another stressor. Many races are held in the summer, and drivers wear hot uniforms and a helmet with no air conditioning in the vehicle (it would use up too much energy). The car itself is sizzling, and it can get as hot as 77°C near the floorboards!

Then there are the G-forces. When a driver turns at high speeds, the pressure against his or her body is reportedly as strong as those on a space shuttle at liftoff. Good upper-body strength is required to withstand the squeeze and to control the car - all at bone-rattling speeds that can surpass 322 km per hour.

Female drivers, who tend to have less lean muscle than males, can be less resistant to fatigue, so increasing stamina is especially important. In fact, the whole racing team must be in great shape - how do you think pit crew members become so quick and agile?

As with other fast-paced sports activities, car racing demands concentration, quick thinking, and good reflexes. During a race, drivers may experience a stress response, or what's known as the fight-or-flight reaction, which is the body's way of preparing us to handle a dangerous situation. The heart rate and blood pressure rise, and the driver feels a rush of energy. He or she may also have a rapid heartbeat, breathing difficulties, sweaty palms, dizziness, or chest pain. When the situation is over (e.g., the race has ended) and the response wears off, the hormone levels drop and the driver begins to feel normal.

Shock is another story. Accidents do happen, but thanks to safety regulations and modern safety equipment, including safety belts and fireproof clothing, most drivers survive their smash-ups with minor injuries. After rolling a vehicle or slamming into a wall or another car, a driver can go into shock as a result of the trauma or injuries. The blood pressure drops too low, and as a result, the organs do not get enough blood flow or oxygen, and cells can die. Symptoms of shock include cold, clammy skin, shallow breathing, vomiting, feelings of faintness or weakness, and unusual thirst. If not treated, shock can cause death. It's a good thing that medical personnel are present at races!

Stress can also come from other sources. Drivers have a hectic schedule of practices, promotional appearances, interviews, and photo shoots, which often involve travelling. It sounds glamorous, but it's hard work! Not only that, but competition can be emotionally stressful. Drivers who perform badly may worry about being dropped from their teams.

To improve racing performance, stay in shape and work out tension, drivers often have strict exercise regimens. It's all part of the job.

While it's unlikely that car racing will ever be added to the roster of Olympic events, professional drivers are as tough as the world-class athletes who do go to the Games. Hopefully, this fact will earn racecar driving even greater respect and attract new fans to NASCAR events.