Comparison of Bone Mineral Density in Adolescent Female Soccer Players, Swimmers, and Weightlifters Materials and Methods Subjects recruited were females between the ages of 8 and 17 years involved in either Olympic- style weight lifting, competition-level swimming, or competition-level tennis. Only subjects who met the following criteria were included; 1) trained at least 5 hours per week, 2) trained at least 10 months of the year, and 3) had been in their respective sport for at least 1 year. The weight lifters were tested as part of the USA Weight Lifting National Junior Olympic/School-Age Championships. The swimmers were state-level competitors tested prior to the Louisiana State Championships and the tennis players were members of a local tennis academy. A total of 19 weight lifters (mean age 12.0  2.1 years), 29 swimmers (mean age 13.6  1.3 years ), and 14 tennis players (mean age 10.8  2.2 years) were tested. All subjects were tested with parental consent or with that of legal guardian. Areal bone densities of the calcaneus were recorded from the right leg of each subject using a Lunar PIXI  portable densitometer. This device allows accurate assessment of BMD with a low radiation exposure making it suitable for use in children. BMD was recorded as the areal density in grams per square centimeter (g/cm 2 ). Each subject was tested only once. Prior to each measurement session, the densitometer was calibrated against a known density and accuracy was determined to be greater than 99%. Conclusion It was hypothesized that adolescent female soccer players would have a higher bone mineral density than weightlifters and swimmers. It was found that the soccer players did have a higher bone mineral density than the weightlifters and swimmers. It was also found that they had higher bone mineral density than World Health Organization normals. These are women who have reached their peak bone mass. In the results of this experiment it was clearly seen that the soccer players had better bone than any of the groups analyzed. The soccer players had.55 gm/cm 2 while the swimmers had.44 gm/cm 2 and the weightlifters had.53 gm/cm 2. When comparing these results to the WHO normals of.50 gm/cm 2 the soccer players had a statistically significant increase in bone mineral density. The bone mineral density of the swimmers was statistically less and the BMD of the weightlifters was not statistically different from the WHO normals. One difference in the athletes was the average age. The soccer players were fifteen- years old while the swimmers were twelve and the weightlifters were thirteen and three fifths years old. This may account for some of the difference in bone mineral density with the soccer players being older, thus giving them more time to lay down bone. However this would not explain the differences in body mass index and bone mineral density. It is generally thought that increased bone mineral density is correlated with increased body mass index. This study showed that the weightlifters had the greatest body mass index but not the greatest bone mineral density. The swimmers had the lowest body mass index and the lowest bone mineral density. The swimmers were also the youngest group out of the three. The soccer players had a body mass index of 19.87kg/m 2, between the weightlifters, kg/m 2, and swimmers, m 2, and the greatest bone mineral density. This does not agree with previous studies that body mass index is directly correlated with bone mineral density. This study tried to show a positive correlation between an impact loading sport, soccer, and increased bone mineral density in adolescent athletes. Although physical activity is positively correlated with bone mineral density, the type of sport and the magnitude of loading continues to be determined. Since the period of greatest bone accrual appears to be in the years of childhood and adolescence this may be the period when activities of skeletal loading may be most beneficial to lay down peak bone mass. The finding regarding soccer players support the use of impact loading exercises such as soccer to potentiate healthy bone prior to adulthood. Further studies need to be done to determine bone mineral density in adolescent females who do not participate in any loading exercises. Other factors that contribute to building maximum bone such as diet, calcium consumption, and sexual maturity need to be taken into consideration. As well bone mineral density at other skeletal sites such as the spine and hip could also be analyzed. Exercise in many different forms along with the recommended daily allowance of calcium is a good recipe toward healthy bone in adulthood to protect against osteoporosis later in life. Hypothesis Soccer players have higher bone mineral density in their heel bone than swimmers, weightlifters, and adult WHO normals. Procedure 1. Obtain voluntary adolescent female subjects for bone mineral density testing by handing out informational flyers to students at CMHS and coaches of the soccer players and various teachers at a number of schools. 2. Schedule appointments for students at either the physicals at Schumpert Hospital, or at the Osteoporosis Center. 3. Have volunteers fill out a consent form and questionnaire; check the consent form upon the arrival of the volunteers. 4. After the consent form is checked, measure the height (cm.) and weight (kg.) of the volunteers and record their data. 5. Sit the volunteer in a regular chair next to the bone mineral density machine. 6. Ask volunteer to remove shoes, socks, and stockings if worn. 7. Place foot in a small saucer shaped opening in the BMD device. 8. Measure bone mineral density. 9. Record the height (cm.), weight (kg), and bone mineral density (g/cmXcm) in a table. 10. After this ten minute process, the volunteers are free to leave, and won’t be asked to return for further involvement. Abstract Osteoporosis and low bone mass are major public health threats in the United States. Exercise is a good way to lay down bone for preventing osteoporosis later in life. The purpose of this study was to compare the levels of bone mineral density in the calcaneus of adolescent female athletes. Soccer players were compared to weight lifters, swimmers and World Health Organization normals. Adolescent female subjects volunteered for a study of bone mineral density testing, after information was handed out at CMHS. Volunteers filled out a consent form and a questionnaire. With informed consent from the parent, the height(cm.) and weight(kg.) of each volunteer were measured. Bone mineral density of the calcaneus was then measured. The height (cm.), weight (kg), and bone mineral density (g/cm x cm) was recorded in a table. The results were compared to bone mineral density of weightlifters, swimmers and WHO normals. The soccer players were significantly different from the other two groups of weightlifters and swimmers. There was no notable difference between weightlifters and the swimmers. When the groups were compared to World Health Organization Norms the soccer players was the only group that had a statistical significant increase in BMD from the WHO normals. Their BMD was increased in the heel bone. This data supports the hypothesis that soccer, an impact loading sport, is an effective way to lay maximum bone down in adolescence. Bone mineral density reached in the soccer players (15 years old) was greater than that of the WHO normals (women years old). Further studies need to be completed to determine the maximal amount of exercise to assure bone accrual in youth. Acknowledgements Laura M. Gehrig, MD*; James W. Bellew, PT, Mentors Louisiana State University Health Sciences Center, Shreveport, LA. Purpose The purpose of this study was to compare the levels of bone mineral density (BMD) in adolescent female athletes. Soccer players were compared to weight lifters, swimmers and adult World Health Organization (WHO) normals. Statistics One Sample Test: Comparing each group to WHO Normals Test Value WHO Normals: gm/cm 2 SWM BMD: p = 0.000*; WGT BMD: p = 0.103; Soccer BMD: p = 0.017* statistically significant NumberMeanStd. DeviationStd. Error Mean Swimming BMD Weightlifting BMD Soccer BMD * *