For Immediate Release
Contact: Donna Krupa [email protected]703.527.7357 or:
Lincoln E. Ford, MD 317.554.0000ext.2965[email protected]
ARE THERE IDEAL SIZES FOR SOME ATHLETICS?After 25 years of investigating the records of world class athletes, a physiologist-physician presents his conclusions
WASHINGTON, DC (September 26, 2000) -- More than 400 years ago, astronomer and mathematician Galileo observed that a small dog could carry three other small dogs on its back; that a man could carry one other man; but a horse was incapable of carrying even one other horse. Galileo called this phenomenon "scaling," theorizing that the bones of larger animals -- such as horses -- needed to be thicker than the bones of small dogs in order to support the greater weight of the structures above them. Galileo was also one of the first to note that small animals have higher metabolic rates than large animals.
-The British physiologist A.V. Hill, who had earlier won the Nobel Prize for his theories of muscle contraction, developed an explanation of how muscle physiology and body dimensions interact. His explanation suggested that animal running speeds would be constant over a wide range of sizes, but that small animals would be much better at acceleration.
One of the greatest athletes in Olympic history, sprinter Jesse Owens, made his living in the early years by betting others that he could outrun a horse over a short distance. Owens had many takers for the bets and he collected every time. Though a sprinter -- not a scientist -- Owens understood intuitively what Nobel Prize winner Hill explained scientifically. Namely, that humans could accelerate faster than large animals. (Owens was also heard to say that he was careful not to run against a quarter horse.)
Harvard's Thomas A. McMahon, one of the world's first bio-mechanical engineers, extended the Galileo and Hill ideas and developed the theory of "elastic scaling." This reconciled the Galielo and Hill theories with that of another scientist, Max Kleiber, who's theory that metabolic rate does not scale with body surface area had predominated for more than a century.
These scientific -- and not so scientific -- theories have been applied to an analysis of world-class athletes as part of a new book entitled, Muscle Physiology and Cardiac Function by Lincoln E. Ford, MD. Dr. Ford, a physiologist and cardiologist of the Indiana University School of Medicine, has included his findings along with a history of the experiments that have led to our current understanding of how the muscle and heart work. Its publication coincides with the American Physiological Society's intersociety meeting, "The Integrative Biology of Exercise," and the Summer 2000 Olympics, and is a thoughtful and entertaining contribution to the history of human physiology research. While he found no evidence that smaller humans are more powerful, he did find that each sport seemed to have an optimum size.
Throughout the research, Ford and his investigators analyzed the records of only the most elite athletes. This stringent selection was necessary because athletic ability is determined by many factors, and it is important that all factors be optimized to recognize the effects of body size. But even with such extreme selection criteria, the results show that world-class athletes whose dimensions are far from the mean do exist, suggesting that training can overcome a size disadvantage. It is important to make this point for two reasons. The first is the scientific conclusion that body dimensions are only one factor in determining athletic ability. The second, and perhaps more important, is that individuals should not be discouraged from participating in a sport simply because they appear to be the "wrong size."
The conclusions Ford and his team reached cover a wide variety of athletics. Highlights of these findings include:
Body Heights of Modern Americans vs. Contemporary AthletesHeight
-- With the exception of basketball, no major sport is dominated by "giants." Conversely, no sport selects individuals with very small sizes, except for jockey and coxswains; and they are transported by other participants. Instead, the optimal sizes for each athletic event are distributed close to the mean heights of all American adults. In their research, Ford et al. analyzed the heights of modern Americans and compared them to the heights of contemporary athletes. They found that the mean height for l8-24 year-old American males is approximately 5'10" (specifically 5'.96" or l76.9 cm). This is two inches taller than the heights compiled from the pediatric tables of the l930s. For women the mean height is 7.7 percent less, or 5'4" (l63.3 cm). The mean heights of the athletes vary only modestly (from -l.4 to +2.4 standard deviations) from the means for average males and females.
The Benefits of Short StatureBoxing
-- There are few large athletes in contact sports that require both strength and speed. The "unlimited" weight category in boxing, for example, has seen few very tall world heavyweight champions. A review of the sizes of the 26 boxers who held the "Undisputed Championship" title since its inception (l899) to l978 (when more than one champion became recognized) showed that the average height and weight were 6'1" (l85 cm) and l98 lbs (90 kgs). These data suggest that the longer reach and greater punching power of larger athletes are insufficient to overcome their reduced acceleration.
Gymnasts
-- The inertial advantage of short stature is also recognized in gymnasts, who are among the shortest athletes. These individuals must perform demanding rotational movements while their bodies are falling through limited distances, and their short limbs and bodies enable more rapid rotational accelerations and therefore more movement while they are in the air.
Football Running Backs
-- Among the elite running backs of professional American football, the researchers found few large athletes in this category. The backs who led the National and American Football Conferences (NFC and AFC, respectively) in rushing for the 32 years from l966 to l997 averaged 5'11" (181 cm) and 210 lbs (95 kgs). The data also show that while these athletes are not exceptionally tall, they are very muscular, having weight-height indices comparable to shot-putters and body-weight-restricted weightlifters. Thus, shorter stature appears to be an asset for this kind of athletics.
Height-Related Limits to the Growth of Muscle
Weightlifting
-- Weightlifting provides an opportunity to assess how large and how strong muscles can grow. For that reason, the researchers reviewed the body weights and amount of weight lifted by the World Weightlifting Federation champions of l993-l997. The results showed that the amount of weight lifted was more closely related to height than to body weight. Additional results showed that both men and women in the "unlimited" weight class reached plateaus in the amount of weight lifted.
Shot-Putting
-- In this event the athlete must accelerate his or her own body mass plus the fixed mass of a "shot." A review of the record holders since World War II show that while these athletes have some of the largest weight-height indices, they were not exceptionally tall. One likely explanation -- supported by the data for weightlifters -- is that there is a height-related upper limit to muscle growth and that when some critical height is exceeded, increasing muscle strength cannot overcome the inertial disadvantages of longer limbs.
Matching Frame Size to Muscle CharacteristicsRunning
-- The authors examined the body dimensions of runners who had either set or tied world records for both the outdoor distances were examined. So too were the records of the 50- and 60-meter indoor sprints. Of the 68 who held multiple records, only seven men and five women held records for distances that differed more than two-fold, indicating that elite running is highly specialized by distance.
-- Sprinting and long distance running favor shorter stature individuals, while middle distances favor taller statures. There is a very sharp division at the height of 6'. Of the 44 men who held records in the 200, 400 or 800 meter distances, 32 were at least 6 feet tall. By contrast only six of the 50 record holders for the 50, 60 or l00 meter sprints were 6' or more and none of the distance runners were taller than 6'.
Tennis
-- The average height of the winners of the four "Grand Slam" tournaments of the World Professional Tennis Tour (Wimbledon, plus the French, Australian and US Open Tournaments) were examined for the years l960-l988. The results showed a 3" (7 cm) increase in the average heights of the athletes between l983 and l985, without a significant increase in height during the periods before l983 or after l985. The cause of the large increase in height has not been identified.
IDEAL SIZES FOR SOME MEN'S ATHLETICS
Sport Body Dimensions WeightShot-putting 6' 4" (192 cm) 255 lbs. (116 kg)Heavyweight boxing 6' 1" (185 cm) 198 lbs. (90 kg) Long-distance running 5' 8" (173 cm) 134 lbs. (61 kg)Middle-distance running 6' 1" (185 cm) 162 lbs. (74 kg)Sprinting 5' 10" (178 cm) 176 lbs. (80 kg)High jumping 6' 4" (194 cm) 172 lbs. (78 kg)Gymnastics 5' 6" (167 cm) 139 lbs. (64 kg)
Exceptions to Size RulesIt is important to make the point that these data are for the most elite athletes in the world. When less stringent selection is made, wider size ranges are found. Examples of professional athletes who don't fit a particular "mold" include the National Basketball Association player who, at 5'3" tall (l60cm), is among one of the most successful in the league. Similarly, while heavyweight boxing champions are clustered around a four inch band (from 5'll" to 6'2"), the entire spectrum spans l3 inches (from 5'7" to 6'7").
Is There An Ideal Sport?An ideal sport might be one without body-size advantages so that all who wish to participate can. The sport that comes closest to meeting this definition is soccer, arguably the world's most popular athletic pastime.
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Physiology research in exercise has been responsible for demonstrating that women are physiologically capable of running the marathon without the event being detrimental to their health and well being; the necessity of competing in a hydrated state, seeking frequent fluid replacement during endurance events; being acclimatized to heat before competition; scheduling competition in the early or late hours of the day; and providing fluids that contain a fixed concentration of glucose during the long distance events; the advantages to athletes -- particularly swimmers -- of tapering in their training before competition; the importance of the specificity concept in athletic training schedules and the acceptance by coaches of team sports that specific power and strength training principles must be followed to enhance performance. The American Physiological Society is devoted to fostering scientific research, education, and the dissemination of scientific information. By providing a spectrum
Editor's Note: Dr. Ford has excellent graphics depicting ideal sizes for certain types of athletics (weightlifting, gymnastics, distance running, high jumping, etc.). To download a copy of the graphics, log on to www.linkford.com. To set up an interview with Dr. Ford, contact him at [email protected]. For further information about physiology, log on to the APS website at www.faseb.org/aps.
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