Effects of low-dose ibuprofen supplementation and resistance training on bone and muscle in postmenopausal women: A randomized controlled trial.

Purpose: To compare the effects of nine months of exercise training and ibuprofen supplementation (given immeditately after exercise sessions) on bone and muscle in postmenopausal women.

Methods: In a double-blind randomized trial, participants (females: n = 90, mean age 64.8, SD 4.

Enhancing a Somatic Maturity Prediction Model.

Purpose: Assessing biological maturity in studies of children is challenging. Sex-specific regression equations developed using anthropometric measures are widely used to predict somatic maturity. However, prediction accuracy was not established in external samples.

Safety and feasibility of a home-based six week resistance training program in juvenile idiopathic arthritis.

Background: Juvenile idiopathic arthritis (JIA), among the most common chronic diseases of childhood, can be associated with attenuated physical activity levels, reduced fitness, decreased functionality and pain. This pilot study aimed to determine the safety, feasibility and effect of a six week resistance training program in children with JIA.

Methods: Youth (8-18 years) with JIA participated in a home-based resistance training program.

Adolescent physical activity and bone strength at the proximal femur in adulthood.

Introduction: Physical activity (PA) enhances bone structural strength at the proximal femur in adolescence, but whether these benefits are maintained into early adulthood remains unknown. The purpose of this study was to investigate whether males and females, described as active, average, and inactive during adolescence, display differences in structural strength at the proximal femur in early adulthood (20-30 yr).

Methods: One hundred four participants (55 males and 49 females) from the Pediatric Bone Mineral Accrual Study (PBMAS) were categorized into adolescent PA groupings (inactive, average, and active) using the Physical Activity Questionnaire for Adolescents.

Does physical activity in adolescence have site-specific and sex-specific benefits on young adult bone size, content, and estimated strength?

The long-term benefits of habitual physical activity during adolescence on adult bone structure and strength are poorly understood. We investigated whether physically active adolescents had greater bone size, density, content, and estimated bone strength in young adulthood when compared to their peers who were inactive during adolescence. Peripheral quantitative computed tomography (pQCT) was used to measure the tibia and radius of 122 (73 females) participants (age mean ± SD, 29.

Role of intensive training in the growth and maturation of artistic gymnasts.

Short stature and later maturation of youth artistic gymnasts are often attributed to the effects of intensive training from a young age. Given limitations of available data, inadequate specification of training, failure to consider other factors affecting growth and maturation, and failure to address epidemiological criteria for causality, it has not been possible thus far to establish cause-effect relationships between training and the growth and maturation of young artistic gymnasts. In response to this ongoing debate, the Scientific Commission of the International Gymnastics Federation (FIG) convened a committee to review the current literature and address four questions: (1) Is there a negative effect of training on attained adult stature? (2) Is there a negative effect of training on growth of body segments? (3) Does training attenuate pubertal growth and maturation, specifically, the rate of growth and/or the timing and tempo of maturation? (4) Does training negatively influence the endocrine system, specifically hormones related to growth and pubertal maturation? The basic information for the review was derived from the active involvement of committee members in research on normal variation and clinical aspects of growth and maturation, and on the growth and maturation of artistic gymnasts and other youth athletes.

Structural strength development at the proximal femur in 4- to 10-year-old precompetitive gymnasts: a 4-year longitudinal hip structural analysis study.

Gymnastics, a high-impact weight-bearing physical activity, has been shown to be highly osteogenic. Previously in this cohort, bone mass development (bone mineral content accrual [BMC]) was shown to be positively associated with low-level (recreational) gymnastics exposure (1 to 2 hours per week); however, BMC is only one single component of bone strength. Bone strength is influenced not only by bone mineralization but also bone geometry, bone architecture, and the imposing loads on the bone.

Influence of nutrition provision during the first two weeks of life in premature infants on adolescent body composition and blood pressure.

Objective: Adequate nutrition is paramount for premature infants. Longitudinal information is scant on the effects of early nutrition and later growth. The purpose of this study was to determine the influence of early energy and protein provision in premature infants on adolescent body composition and blood pressure.

Ingestion of low-dose ibuprofen following resistance exercise in postmenopausal women.

Background: Postmenopausal women typically experience accelerated muscle loss which has a negative effect on strength. The maximum daily recommended dosage of ibuprofen (1,200 mg) following resistance exercise has been shown to increase muscle hypertrophy and strength in older adults. This study aimed to determine the effects of low-dose ibuprofen (400 mg) immediately following resistance exercise sessions on muscle mass and strength in postmenopausal women.

Former premenarcheal gymnasts exhibit site-specific skeletal benefits in adulthood after long-term retirement.

Young female gymnasts have greater bone strength compared to controls; although possibly due to selection into gymnastics, it is thought that their loading activity during growth increases their bone mass, influencing both bone geometry and architecture. If such bone mass and geometric adaptations are maintained, this may potentially decrease the risk of osteoporosis and risk of fracture later in life. However, there is limited evidence of the persisting benefit of gymnastic exercise during growth on adult bone geometric parameters.

Higher premenarcheal bone mass in elite gymnasts is maintained into young adulthood after long-term retirement from sport: a 14-year follow-up.

Sports that impact-load the skeleton during childhood and adolescence increase determinants of bone strength such as bone mineral content and density; however, it is unclear if this benefit is maintained after retirement from the sport. The purpose of this study was to assess whether the previously reported higher bone mass in a group of premenarcheal gymnasts was still apparent 10 years after the cessation of participation and withdrawal of the gymnastics loading stimulus. In 1995, 30 gymnasts 8 to 15 years of age were measured and compared with 30 age-matched nongymnasts.

Maturational timing does not predict HSA estimated adult bone geometry at the proximal femur.

Late maturational timing is documented to be detrimental to bone strength primarily at the distal radius. Studies at the proximal femur have focused on bone mass and the results remain controversial. The purpose of this study was to examine the long term relationship between the onset of maturation and the development of estimated cross sectional area (CSA) and section modulus (Z) at the proximal femur.

Forearm muscle size, strength, force, and power in relation to pQCT-derived bone strength at the radius in adults.

We aimed to examine the relationship between forearm muscle cross-sectional area (MCSA), muscle force, or rate of torque development (RTD) and 2 estimated radius bone strength indices - compressive bone strength index (BSI) at the wrist and strength strain index in torsion (SSI(p)) at the shaft - in healthy middle-aged males and females. Distal (4%) and shaft (65%) sites of nondominant forearms were scanned using peripheral quantitative computed tomography (pQCT) in a sample of 48 adults (mean age ± SD, 49.4 ± 2.

The timing of BMD and geometric adaptation at the proximal femur from childhood to early adulthood in males and females: a longitudinal study.

During adolescence, the peak velocity in bone mass accretion preceded the peak velocity of estimated geometry at the hip. Whether this pattern continues into adulthood when maximum values are achieved remains unknown. The purpose of this study was (1) to identify the ages at which peak values of areal BMD (aBMD), cross-sectional area (CSA), and section modulus (Z) occur, (2) to determine the percent of adult peak attained during adolescence, and (3) to determine the relationship between body composition and the timing of the adult peak values.

Bone mineral accrual from 8 to 30 years of age: an estimation of peak bone mass.

Bone area (BA) and bone mineral content (BMC) were measured from childhood to young adulthood at the total body (TB), lumbar spine (LS), total hip (TH), and femoral neck (FN). BA and BMC values were expressed as a percentage of young-adult values to determine if and when values reached a plateau. Data were aligned on biological ages [years from peak height velocity (PHV)] to control for maturity.

Effect of maturational timing on bone mineral content accrual from childhood to adulthood: evidence from 15 years of longitudinal data.

A higher bone mass may reduce the risk of osteoporosis and fractures. The role of maturational timing for optimizing bone mass is controversial due to the lack of prospective evidence from childhood to adulthood. The purpose of this study was to examine the long term relationship between the onset of maturation and bone mineral content (BMC) development.

Bone mineral accrual in 4- to 10-year-old precompetitive, recreational gymnasts: a 4-year longitudinal study.

Competitive female gymnasts have greater bone mineral measures than nongymnasts. However, less is known about the effect of recreational and/or precompetitive gymnastics participation on bone development. The purpose of this study was to investigate whether the differences previously reported in the skeleton of competitive female gymnasts are also demonstrated in young children with a current or past participation history in recreational or precompetitive gymnastics.

Relationship between trajectories of trunk fat mass development in adolescence and cardiometabolic risk in young adulthood.

To examine developmental trajectories of trunk fat mass (FM) growth of individuals categorized as either low or high for cardiometabolic risk at 26 years, a total of 55 males and 76 females from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2007) were assessed from adolescence (11.5 ± 1.8 years) to young adulthood (26.

Does controlling for biological maturity improve physical activity tracking?

Unlabelled: Tracking of physical activity through childhood and adolescence tends to be low. Variation in the timing of biological maturation within youth of the same chronological age (CA) might affect participation in physical activity and may partially explain the low tracking.

Purpose: To examine the stability of physical activity over time from childhood to late adolescence when aligned on CA and biological age (BA).

Adolescent biological maturity and physical activity: biology meets behavior.

The decline in physical activity (PA) across adolescence is well established but influence of biological maturity on the process has been largely overlooked. This paper reviews the limited number of studies which examine the relationship between timing of biological maturity and PA. Results are generally inconsistent among studies.

Preterm birth and adolescent bone mineral content.

The purpose of this study was to determine the influence of preterm low birth weight on bone mineral content in adolescence. In 2007 to 2008, data on adolescents were obtained for study, including 16 females and 25 males who were born preterm (≤37 weeks' gestation) between October 1, 1989, and December 31, 1995, with a birth weight of less than 1850 g. Preterm low-birth-weight individuals were age- and sex-matched to full-term (>37 weeks) normal-birth-weight (>2500 g) controls.

Does childhood and adolescence fracture influence bone mineral content in young adulthood?

Previous fracture may predispose an individual to bone fragility because of impaired bone mineral accrual. The primary objective of the study was to investigate the influence of fractures sustained during childhood and (or) adolescence on total body (TB), lumbar spine (LS), femoral neck (FN), and total hip (TH) bone mineral content (BMC) in young adulthood. It was hypothesized that there would be lower TB, LS, FN, and TH BMC in participants who had sustained a pediatric fracture.

Assessment of total and central adiposity in Canadian Aboriginal children and their Caucasian peers.

Objective: Although Aboriginal children seem to be more susceptible to developing obesity and metabolic disorders than other ethnic groups in Canada, few studies have examined adiposity comprehensively in this population. The purpose of this study was to assess total and central adiposity in Canadian Aboriginal and Caucasian children matched by age, gender and maturity.

Methods: A total of 212 Aboriginal and 204 Caucasian children (8-17 years) were recruited.

International longitudinal pediatric reference standards for bone mineral content.

To render a diagnosis pediatricians rely upon reference standards for bone mineral density or bone mineral content, which are based on cross-sectional data from a relatively small sample of children. These standards are unable to adequately represent growth in a diverse pediatric population. Thus, the goal of this study was to develop sex and site-specific standards for BMC using longitudinal data collected from four international sites in Canada and the United States.

Calcium requirements for bone growth in Canadian boys and girls during adolescence.

Adequate dietary intake during the growth period is critical for bone mineral accretion. In 1997, an adequate intake (AI) of 1300 mg/d Ca was set for North American adolescents aged 9-18 years based on best available data. We determined bone Ca accrual values from age 9 to 18 years taking into account sex and maturity.