Mineral deposition on bone matrix begins during fetal life, continues at an accelerated rate during childhood/adolescence, and ends at the beginning of adulthood. 1 Regarding acquisition of bone mass, puberty is crucial to the development of bone matrix and constitutes a relevant determinant of
Alessandra Madia Mantovani, Manoel Carlos Spiguel de Lima, Luis Alberto Gobbo, Enio Ricardo Vaz Ronque, Marcelo Romanzini, Bruna Camilo Turi-Lynch, Jamile Sanches Codogno and Rômulo Araújo Fernandes
Susan K. Grimston, Jack R. Engsberg, Reinhard Kloiber and David A. Hanley
Increased incidence of stress fracture has been reported for amenorrheic runners, while some studies have reported decreased spinal bone mass in amenorrheic runners. Based on results from these studies, one tends to associate decreased spinal bone mass with an increased risk of stress fracture. The present study compared regional bone mass and external loads during running between six female runners reporting a history of stress fracture (seven tibial and three femoral neck) and eight female runners with no history of stress fracture. Dual photon absorptiometry measures indicated significantly greater spinal (L2-L4) and femoral neck bone mineral density in stress fracture subjects (p<0.05) but no differences between groups for tibial bone density. Normalized forces recorded from Kistler force plates indicated significantly greater vertical propulsive, maximal medial, lateral, and posterior forces for stress fracture subjects during running (p<0.05).
Miia Suuriniemi, Harri Suominen, Anitta Mahonen, Markku Alén and Sulin Cheng
This follow-up study confirms our previous findings that the ER-α PvuII polymorphism (Pp) modulates the association between exercise and bone mass. The differences in bone properties of girls with consistently low physical activity (LLPA) and consistently high physical activity (HHPA) were evident only in those bearing the heterozygote ER-α genotype (Pp). In particular, areal bone mineral density of the total femur, bone mineral content and areal bone mineral density of the femoral neck, and bone mineral content and cortical thickness of the tibia shaft were significantly (p < .05) lower in the Pp girls with LLPA than in their HHPA counterparts. These findings might partly explain the genetic basis of human variation associated with exercise training.
Alba Gómez-Cabello, Germán Vicente-Rodríguez, Isabel Navarro-Vera, Diana Martinez-Redondo, Carmen Díez-Sánchez and José Antonio Casajús
The aim of this study was to provide information about the relationship of bone mineral content (BMC) and density (BMD) with some physical-fitness-related variables in a sample of women with fibromyalgia (FM) and age-matched women without FM. Twenty-eight women clinically diagnosed with FM (age 51.1 ± 8.4 yr, M ± SD) and 22 age-matched controls participated in the study. Whole-body BMC and BMD, lean mass, handgrip strength, quadriceps strength, and cardiovascular fitness were measured in all participants. The association between physical-fitness variables and bone-related variables was tested by linear regression controlling for body weight as a possible confounder. There were no differences in BMC or BMD between groups. Women with FM had lower values of handgrip strength, quadriceps strength, and VO2peak than the control group. Handgrip strength and aerobic capacity were associated with BMC and BMD and quadriceps strength was associated with BMD in women with FM; however, only VO2peak was associated with BMC in the group of women without FM. Bone mass of women with FM may be more susceptible to changes in physical fitness than that of the women without fibromyalgia.
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.
Agnieszka Kaczmarek, Alicja Nowak and Piotr Leszczynski
An increased occurrence of lifestyle-related diseases such as osteoporosis indicates the necessity for taking preventive action, including regularly engaging in physical activity. The aim of the study was to assess the areal bone mineral density (aBMD) and bone turnover markers levels in young adult women engaging in recreational horseback riding and to determine the relationship between training characteristics and bone metabolism indices.
The study involved 43 women: 23 equestrians and 20 age- and body mass index–matched controls. The hip and spine aBMD and serum levels of the bone turnover markers: osteocalcin and collagen type I cross-linked C-telopeptide were measured.
No significant differences were found in somatic features, concentrations of bone turnover markers, or bone mass variables. Correlation analysis of the equestrian participants showed significant relationship between body mass and BMDL1–L4 (P < .05) as well as between BMI and BMDL1–L4 (P ≤ .01) and z-score L1–L4 (P < .05).
The study showed no differences in bone mass and levels of bone metabolic indices between groups of women practicing horseback riding at the recreational level and subjects who do not participate in frequent systematic physical activity. No relationship between training characteristics and bone turnover markers were found.
Belinda R. Beck
rapidly until 16, after which time growth slows through the end of the third decade ( 75 ). Another group measured BMC and BMD at different skeletal sites in 151 White European girls at the onset of puberty, during puberty, and at menarche, and similarly observed that the increase in bone mass formation
Daniel Courteix, Christelle Jaffré, Philippe Obert and Laurent Benhamou
The aim of this study was to assess the effects of vigorous activity on the somatic and skeletal growths in young females reaching puberty. From a group of 41 prepubertal girls, 24 remained in this study: 10 gymnasts training 15 to 22 hr a week and 14 non-exercising controls. At the start and during the study period, bone age, height, weight, fat and lean mass were significantly lower in the gymnasts vs. the controls (p < .05). These variables had increased in the same way for both groups. At each investigation, the gymnasts had significantly higher BMC, BMD, and BMAD at all the sites (p < .01) except the whole body. The strong correlation between somatic measurements at the start and at the end of the study indicated that physical exercise does not disrupt the normal growth in these children.
Stephanie M. Miller, Sonja Kukuljan, Anne I. Turner, Paige van der Pligt and Gaele Ducher
Prevention of the female athlete triad is essential to protect female athletes’ health. The aim of this study was to investigate the knowledge, attitudes, and behaviors of regularly exercising adult women in Australia toward eating patterns, menstrual cycles, and bone health.
A total of 191 female exercisers, age 18–40 yr, engaging in ≥2 hr/wk of strenuous activity, completed a survey. After 11 surveys were excluded (due to incomplete answers), the 180 participants were categorized into lean-build sports (n = 82; running/athletics, triathlon, swimming, cycling, dancing, rowing), non-lean-build sports (n = 94; basketball, netball, soccer, hockey, volleyball, tennis, trampoline, squash, Australian football), or gym/fitness activities (n = 4).
Mean (± SD) training volume was 9.0 ± 5.5 hr/wk, with participants competing from local up to international level. Only 10% of respondents could name the 3 components of the female athlete triad. Regardless of reported history of stress fracture, 45% of the respondents did not think that amenorrhea (absence of menses for ≥3 months) could affect bone health, and 22% of those involved in lean-build sports would do nothing if experiencing amenorrhea (vs. 3.2% in non-lean-build sports, p = .005). Lean-build sports, history of amenorrhea, and history of stress fracture were all significantly associated with not taking action in the presence of amenorrhea (all p < .005).
Few active Australian women are aware of the detrimental effects of menstrual dysfunction on bone health. Education programs are needed to prevent the female athlete triad and ensure that appropriate actions are taken by athletes when experiencing amenorrhea.
Ann V. Rowlands, Sarah M. Powell, Roger G. Eston and David K. Ingledew
This study aimed to determine the relationship between bone mineral content, habitual physical activity, and calcium intake in children. Fifty-seven children, aged 8–11 years, wore pedometers for seven days to assess activity. Calcium intake was estimated by a 4-day food diary. Bone mineral content (BMC) and areal density (BMD) were measured at the total proximal femur and femoral neck using dual energy X-ray absorptiometry. Regression analysis was used to assess contributions of physical activity and calcium intake to BMC, residualized for bone area and body mass. Physical activity explained 11.6% of the variance in residualized BMC at the proximal femur and 14.3% at the femoral neck (p < 0.05). Calcium intake added to the variance explained at the proximal femur only (9.8%, p < 0.05). This study provides evidence for an association between BMC and habitual physical activity.