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Rossana C. Nogueira, Benjamin K. Weeks and Belinda R. Beck

Our goal was to test the effect of a brief, novel bone- and fat-targeted exercise program on bone, muscle, and fat in healthy pre and peripubertal boys. We conducted a 10-min, 3/wk capoeira and jumping exercise intervention for 9 months with year 5 and 6 school boys. Anthropometrics, maturity, heart rate, blood pressure, maximal vertical jump, aerobic capacity and calcaneal broadband ultrasound attenuation and stiffness index (BUA and SI; Achilles, GE) were assessed. Bone, lean and fat tissue (DXA; XR800, Norland), and parameters of bone geometry (pQCT, XCT3000, Stratec) were measured from a subsample of 36 boys. Of 188 boys (10.6 ± 0.5 yr) who consented, 172 completed all testing; 104 exercisers (EX) and 68 controls (CON). 30 EX and 6 CON participants underwent DXA and pQCT measures. EX improved BUA (+4.3% vs. +2.1%, p = .035), waist circumference (+2.8% vs. +6.2%, p = .001), heart rate (-5.3% vs. +1.5%, p = .005), maximal vertical jump (+12.2% vs. −0.3%, p = .001) and estimated maximal oxygen consumption (+9.1% vs. +1.2%, p = .001) compared with CON. Three 10-min sessions of capoeira and jumping per week improved calcaneal bone and metabolic health of pre and peripubertal boys over the course of a school year with little disruption to the academic schedule.

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Dennis E. Anderson and Michael L. Madigan

Maintenance of healthy bone mineral density (BMD) is important for preventing fractures in older adults. Strains experienced by bone in vivo stimulate remodeling processes, which can increase or decrease BMD. However, there has been little study of age differences in bone strains. This study examined the relative contributions of age-related differences in femoral loading and BMD to age-related differences in femoral strains during walking using gait analysis, static optimization, and finite element modeling. Strains in older adult models were similar or larger than in young adult models. Reduced BMD increased strains in a fairly uniform manner, whereas older adult loading increased strains in early stance but decreased strains in late stance. Peak ground reaction forces, hip joint contact forces, and hip flexor forces were lower in older adults in late stance phase, and this helped older adults maintain strains similar to those of young adults despite lower BMD. Because walking likely represents a “baseline” level of stimulus for bone remodeling processes, increased strains during walking in older adults might indicate the extent of age-related impairment in bone remodeling processes. Such a measure might be clinically useful if it could be accurately determined with age-appropriate patient-specific loading, geometry, and BMD.

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Kerri M. Winters-Stone and Christine M. Snow

We conducted a double-blind, placebo-controlled, randomized trial to determine whether 1 year of supplemental calcium intake would augment hip [greater trochanter, GT, femoral neck (FN), total hip (TH)], spine (LS), and femoral mid-shaft (Fmr) BMD in female distance runners. Twenty-three women (age: 23.7 ± 4.7 yrs, height: 165.6 ± 6.3 cm, weight: 55.7 ± 6.1 kg) were randomly assigned to receive either 1000 mg/d of supplemental calcium (N = 13) or placebo tablets (N = 10) for 1 year. BMD was determined by DXA (Hologic 1000-W) and tablet compliance by self-report logs. Compliance averaged 79% and 71% for supplement and placebo groups, respectively. Calcium supplementation did not affect hip or spine BMD, but did prevent loss at the femoral mid-shaft (GT: –0.5% vs. 0.2%, FN: 0.9% vs. 1.1%, TH: –0.3% vs. 0.2%, LS: 0.3% vs. 1.2%, Fmr: 0.1% vs. –1.8%, for calcium vs. placebo, respectively). We conclude that the addition of 800 mg/d of supplemental calcium to the diet of young adult female distance runners with habitual calcium intakes of ~1000 mg/d, prevents cortical but not trabecular bone loss.

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Alon Eliakim, Ita Litmanovitz and Dan Nemet

technologies, has placed an increased need to address other preterm diseases that develop later in the neonatal period like osteopenia of prematurity ( 27 ). Metabolic bone disease is relatively common in preterm infants because the period of greatest bone mineral accretion occurs in the last trimester of

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Tracey L. Clissold, Paul W. Winwood, John B. Cronin and Mary Jane De Souza

Osteoporosis is a condition where bone density and bone strength is reduced, and there is a significantly increased risk of bone fracture. 1 Osteoporosis is a silent epidemic responsible for fractures in 50% of women and 20% of men worldwide. 2 Approximately 52 million women and men have

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Paige E. Rice, Herman van Werkhoven, Edward K. Merritt and Jeffrey M. McBride

bone mineral density, bone mineral content, and bone-strength indices, which may influence factors reflective of bone health such as stress–strain index and ultimate fracture load. 5 Muscle cross-sectional area, muscle strength, peak force, and peak power measurements during jumping have shown to

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Lauren A. Burt, David A. Greene and Geraldine A. Naughton

High-impact activities have been shown to increase bone density more than low-impact or weight-supported sports ( 27 , 30 ). Gymnastics is a substantially high-impact sport, and among female gymnasts, higher bone density has been reported ( 4 ). Because gymnastics is an early specialization sport

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Eric Tsz-Chun Poon, John O’Reilly, Sinead Sheridan, Michelle Mingjing Cai and Stephen Heung-Sang Wong

safety concern that high-speed falls and bone fractures are frequent ( Rueda et al., 2010 ), achieving optimal bone health is of paramount importance for jockeys. However, previous research suggested that extreme dietary weight-making practices can result in an inadequate intake of macronutrients and

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Belinda R. Beck

puberty. Such may be the case for exercise and bone. Statements that bone is optimally responsive to the stimulus of exercise in the years prior to puberty are abundant in the literature ( 9 , 15 , 16 , 27 , 30 , 76 , 85 ), and a multitude of works has been cited to support the claim ( 2 , 7 , 8 , 10 , 12

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Ammar Nebigh, Mohamed Elfethi Abed, Rihab Borji, Sonia Sahli, Slaheddine Sellami, Zouhair Tabka and Haithem Rebai

Physical activity plays an important role in tissue metabolism, growth, and development, but the mechanisms that link patterns of exercise with tissue anabolism are not completely understood ( 21 , 26 ). It is widely established that the bone mass gain from exercise is principally a response to an