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Shreela V. Sharma, Deanna M. Hoelscher, Steven H. Kelder, Pamela M. Diamond, R. Sue Day and Albert C. Hergenroeder

Background:

The purpose of this study was to identify pathways used by psychosocial factors to influence physical activity and bone health in middle-school girls.

Methods:

Baseline data from the Incorporating More Physical Activity and Calcium in Teens (IMPACT) study collected in 2001 to 2003 were used. IMPACT was a 1 1/2 years nutrition and physical activity intervention study designed to improve bone density in 717 middle-school girls in Texas. Structural Equations Modeling was used to examine the interrelationships and identify the direct and indirect pathways used by various psychosocial and environmental factors to influence physical activity and bone health.

Results:

Results show that physical activity self-efficacy and social support (friend, family engagement, and encouragement in physical activity) had a significant direct and indirect influence on physical activity with participation in sports teams as the mediator. Participation in sports teams had a direct effect on both physical activity (β= 0.20, P < .05) and bone health and (β=0.13, P < .05).

Conclusion:

The current study identified several direct and indirect pathways that psychosocial factors use to influence physical activity and bone health among adolescent girls. These findings are critical for the development of effective interventions for promoting bone health in this population.

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Bronwen Lundy

Synchronized swimming enjoys worldwide popularity and has been part of the formal Olympic program since 1984. Despite this, relatively little research has been conducted on participant nutrition practices and requirements, and there are significant gaps in the knowledge base despite the numerous areas in which nutrition could affect performance and safety. This review aimed to summarize current findings and identify areas requiring further research. Uniform physique in team or duet events may be more important than absolute values for muscularity or body fat, but a lean and athletic appearance remains key. Synchronized swimmers appear to have an increased risk of developing eating disorders, and there is evidence of delayed menarche, menstrual dysfunction, and lower bone density relative to population norms. Dietary practices remain relatively unknown, but micronutrient status for iron and magnesium may be compromised. More research is required across all aspects of nutrition status, anthropometry, and physiology, and both sports nutrition and sports medicine support may be required to reduce risks for participants.

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Joseph M. Kindler, Hannah L. Ross, Emma M. Laing, Christopher M. Modlesky, Norman K. Pollock, Clifton A. Baile and Richard D. Lewis

Assessment of physical activity in clinical bone studies is essential. Two bone-specific physical activity scoring methods, the Bone Loading History Questionnaire (BLHQ) and Bone-Specific Physical Activity Questionnaire (BPAQ), have shown correlations with bone density and geometry, but not architecture. The purpose of this study was to determine relationships between physical activity scoring methods and bone architecture in non-Hispanic white adolescent females (N = 24; 18-19 years of age). Bone loading scores (BLHQ [hip and spine] and past BPAQ) and energy expenditure (7-day physical activity recall) were determined from respective questionnaires. Estimates of trabecular and cortical bone architecture at the nondominant radius and tibia were assessed via magnetic resonance imaging. Total body and regional areal bone mineral density (aBMD), as well as total body fat mass and fat-free soft tissue (FFST) mass were assessed via dual energy X-ray absorptiometry. Pearson’s correlations and partial correlations adjusting for height, total body fat mass, and FFST were performed. Hip BLHQ scores were correlated with midtibia cortical volume (r = .43; p = .03). Adjusted hip and spine BLHQ scores were correlated with all midtibia cortical measures (r = .50-0.58; p < .05) and distal radius apparent trabecular number (r = .46-0.53; p < .05). BPAQ scores were correlated with all midtibia cortical (r = .41-0.51; p < .05) and most aBMD (r = .47-0.53; p < .05) measures. Energy expenditure was inversely associated with femoral neck aBMD only after statistical adjustment (r = .49, p < .05). These data show that greater load-specific physical activity scores, but not energy expenditure, are indicative of greater midtibia cortical bone quality, thus supporting the utility of these instruments in musculoskeletal research.

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John Petrizzo, Frederick J. DiMenna, Kimberly Martins, John Wygand and Robert M. Otto

To achieve the criterion appearance before competing in a physique competition, athletes undergo preparatory regimens involving high-volume intense resistance and aerobic exercise with hypocaloric energy intake. As the popularity of “drug-free” competition increases, more athletes are facing this challenge without the recuperative advantage provided by performance-enhancing drugs. Consequently, the likelihood of loss of lean body and/or bone mass is increased. The purpose of this investigation was to monitor changes in body composition for a 29-year-old self-proclaimed drug-free female figure competitor during a 32-week preparatory regimen comprising high-volume resistance and aerobic exercise with hypocaloric energy intake. We used dual-energy x-ray absorptiometry (DXA) to evaluate regional fat and bone mineral density. During the initial 22 weeks, the subject reduced energy intake and engaged in resistance (4–5 sessions/week) and aerobic (3 sessions/week) training. During the final 10 weeks, the subject increased exercise frequency to 6 (resistance) and 4 (aerobic) sessions/week while ingesting 1130–1380 kcal/day. During this 10-week period, she consumed a high quantity of protein (~55% of energy intake) and nutritional supplements. During the 32 weeks, body mass and fat mass decreased by 12% and 55%, respectively. Conversely, lean body mass increased by 1.5%, an amount that exceeded the coefficient of variation associated with DXA-derived measurement. Total bone mineral density was unchanged throughout. In summary, in preparation for a figure competition, a self-proclaimed drug-free female achieved the low body-fat percentage required for success in competition without losing lean mass or bone density by following a 32-week preparatory exercise and nutritional regimen.

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Susan Carter

.H. , 3rd . ( 1990 ). Menstrual history as a determinant of current bone density in young athletes . Journal of the American Medical Association, 263 ( 4 ), 545 – 548 . PubMed ID: 2294327 doi:10.1001/jama.1990.03440040084033 10.1001/jama.1990.03440040084033 Drinkwater , B.L. , Nilson , K

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Paula B. Costa, Scott R. Richmond, Charles R. Smith, Brad Currier, Richard A. Stecker, Brad T. Gieske, Kimi Kemp, Kyle E. Witherbee and Chad M. Kerksick

and concluded that strength, muscular endurance, and aerobic capacity were important attributes but did not have any measures of bone health, EI, or EA. To our knowledge, no literature exists on the bone density, body composition, resting metabolism, EA, and dietary intake of competitive, collegiate

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Heather L. Colleran, Andrea Hiatt, Laurie Wideman and Cheryl A. Lovelady

was made after baseline measurements were completed. All participants were given a year’s supply of a multivitamin supplement containing 10 μg of vitamin D. Laboratory Measurements BMD and Anthropometrics Bone density was measured using a different dual-energy X-ray absorptiometry machine for each

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Maja Zamoscinska, Irene R. Faber and Dirk Büsch

was searched in July 2019 by using combinations of the terms: “osteoporosis” OR “osteopenia” OR “bone loss” (P) AND “strength training” OR “resistance training” (I) AND “bone density” OR “BMD” (O). Titles, abstracts, and/or full texts were used to check for the inclusion and exclusion criteria

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Laura S. Kox, P. Paul F.M. Kuijer, Dagmar A.J. Thijssen, Gino M.M.J. Kerkhoffs, Rick R. van Rijn, Monique H.W. Frings-Dresen and Mario Maas

, osteoarthritis, bone density, pain, disability, or radiographic abnormalities, such as ulnar variance, preferably compared with health effects in the absence of wrist-loading sports during youth. Measures of exposure of the wrist to repetitive loading during sports participation were collected preferably in

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Thomas Cattagni, Vincent Gremeaux and Romuald Lepers

scores of BMD were used to compare DL with healthy young females with peak bone mass according to the manufacturer’s instructions and the World Health Organization. 21 A T score between +1 and −1 denotes normal bone density. A T score between −1 and −2.5 indicates low bone density or osteopenia. A T