GENDER- AND HEIGHT-RELATED LIMITS OF MUSCLE STRENGTH FOUND IN WORLD WEIGHTLIFTING CHAMPIONS

In a new study of the World Weightlifting Federation champions of l993-l997, researchers found a near constant amount of body mass is devoted to muscle in lighter weightlifters, but a lesser fraction exists among heavier lifters; results transcend gender lines

Portland, ME (Sept. 22, 2000) — What factors limit human strength and growth in male and female weightlifters?  A study of the World Weightlifting Federation champions of  l993-l997 was conducted by Lincoln E. Ford, MD and his colleagues, and the results published in the recent academic journal of the American Physiological Society, the Journal of Applied Physiology.

Dr. Ford, a cardiologist and physiologist, is also a professor of Medicine, Physiology and Biophysics at the Indiana University School of Medicine and the director of the Heart Failure and Post-Heart Transplant Clinic at the Indianapolis VA Medical Center. He is available to discuss his findings, “Gender- and Height-Related Limits of Muscle Strength In World Weightlifting Champions.”

Background: The object of weightlifting competition – believed to be more than 6,000 years old -- is to achieve the greatest cumulative score during six attempts at lifting weights. Three attempts are made using the “snatch” technique; three utilize the “clean-and-jerk” method. During the Summer 2000 Olympics men will compete in one of seven weight class categories ranging from 56-l05 kgs. An eighth, or “unlimited,” class is reserved for weights in excess of l05 kg.  The Olympics inaugurates the female weightlifting division this year with participants competing within seven divisions, subdivided into classes ranging from 48-75kg. There is also an “unlimited” weight category for women lifting weights of 75+kg.

The Study: To assess the factors that limit human muscle strength and growth, the Ford team examined the relationship between performance and body dimensions in the world weightlifting champions of l993-l997.

Methodology: The investigators obtained the identities, body weights and amount of weight lifted for the champions of  the l993-l997 from the World Weightlifting Federation. Data were gathered for 95 champions who were distributed among l9 weight classes and won by 68 athletes. The heights of 68 of the 95 champions were also obtained and compared with the categories . For males, ten body-weight classes (54, 59, 64, 70, 76, 83,091, 99, 108 and l08+) were examined. For females, nine classes (46, 50, 54,59, 64, 70, 76, 83 and 83+) were analyzed. 

Results:   

• The researchers found that weight lifted was more closely related to height than to body weight. For lighter champions, there was a nearly constant relationship of weight-lifted to body cross-sectional area (defined as body weight divided by height), but this ratio declined for the heavier champions.

• The ratio weight-lifted to height-squared was constant for all body-weight classes, including the unlimited class.  While heavyweight champions weighed 61% more than the next heaviest champions, they lifted only 6% more weight, and were no taller than 183 cm.

• More interestingly, there was a constant ratio of weight lifted-to-height squared for all body weight classes, including the unlimited class. (While the ratio was less for women champions it was also constant across all body weight classes.)

• A further interesting finding is that only one male champion was taller than 183 cm (6 feet) and no female champion was taller than 175 cm (5' 9").

• Among women, the unlimited class champions lifted less weight than the heaviest limited class champions, suggesting that the plateau of strength occurs at body weights below 83 kg. The ratio of weight-lifted to height-squared was also constant across all body weight classes, including the unlimited class champions who were no taller than 175 cm.  Among women, muscle strength reached a maximum at a height of 5. 9". 

 Conclusions:

• The principal conclusion is that muscle strength and height are related by a common factor, and that muscle strength approaches absolute maxima at heights of approximately l83 cm for men and l75 cm for women. 

• A second conclusion is that the ratios of weight lifted-to-cross-sectional area in heavier athletes decline above a specific threshold, possibly because of an increasing percentage of non-contractile tissue contributing to body weight.

• The final conclusion is that these ratios in women are a constant fraction of the ratios in men and when proper adjustment is made for gender differences in the thresholds where the increased fraction of non-contractile tissue begins.

•  These findings suggest that muscle strength and growth are determined by a factor closely associated with the factor that determines bone growth and height, regardless of gender.

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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 of physiological information, the Society plays a significant role in the progress of science and the advancement of knowledge.

Editor's Note: For further information or to schedule an interview, contact Donna Krupa at 703.527.7357; cell: 703.967.2751; or at djkrupa1@aol.com; or visit the APS website at www.the-aps.org.