You watch a motocross or supercross event, and you say, "Great riders." Indeed. But "great athletes" applies as well in motocross and supercross. So does "best-conditioned athletes."
Motocross enthusiasts still point to a 1980 study by the National Sports Health Institute in Englewood, California. Athletes in various athletic endeavors were tested for levels of physical conditioning. Motocross riders scored higher than athletes in sports ranging from American football to basketball to track and tennis. Overall, motocross riders placed second only to soccer players.
More recent follow-up studies have yielded similar results, from sources that include the medical schools at the University of Florida and the University of Pittsburgh. On a typical day of motocrossracing, riders must participate in qualifying heats in order to qualify for the real races, also known as "motos." A typical moto lasts about 40 minutes, and there isn't just one, there are two. The rider must keep complete control of a bike that weighs more than 200 pounds, while maintaining top speed and fighting for top position among competing riders. Fans see thrills and spills, but riders feel the muscle strains and the injury pains.
The University of Florida researchers, in cooperation with the Jacksonville Orthopedic Institute, reported, "Supercross and motocross are physically demanding sports. The cardiovascular demands are higher than have been reported for professional road cyclist during similar duration events and for professional mountain bikers during events on similar terrain." That's saying a lot!
A physical fitness web site, hyperstrike.com, asserts, "At first sight, motocross racing is a spectacular and entertaining game, but the physical demands of this sport are beyond what a mere spectator could imagine." As a result, motocross racing requires a unique blend of strength, power, flexibility and endurance.
Former motocross star Brad Lackey was part of the historic study by the National Sports Health Institute. Lackey recalls that the motocross riders who were in the best shape had body fat ratios of less than 10 percent. Even though the riders are not muscularly "sculpted" like athletes such as gymnasts, they are noted for having extremely strong arms and legs, with cardiovascular systems similar to marathon runners. "The muscles are endurance muscles, and they're really strong, but you can't really see that," Brad Lackey observed. "When you're doing 45-minute motos, you're not big and bulky. The body just doesn't show how good physically you are."
Sources:
http://en.wikipedia.org/wiki/Motocross#Physical_demands
http://www.racerxvt.com/virtual_trainer/Dr_A_heart_rate.html
http://www.articlecube.com/article.php?id=268521&act=print
http://www.motocrosscanada.ca/modules.php?op=modload&name=News&file=article&sid=1800&mode=thread&order=0&thold=0