Self-reported recreational exercise combining regularity and impact is necessary to maximize bone mineral density in young adult women (original) (raw)
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Calcified Tissue International, 2006
Girls who exercise athletically have higher bone mass than their sedentary counterparts, and this difference may be sustained in adulthood. However, whether moderate physical activity during youth confers lasting benefits for bone is unclear. We explored lifetime physical activity and current areal bone mineral density (aBMD) in 78 postmenopausal women with no known history of osteoporosis. Subjects reported physical activity for four age periods (12–18, 19–34, 35–49, ≥ 50 years) using the Historical Leisure Activity Questionnaire, completed two 3-day food records, had measurements of height and weight, and aBMD assessed using dual-energy X-ray absorptiometry at the lumbar spine (L1-4) and proximal femora. Low aBMD was detected at the lumbar spine in 43 (56%) women and at the proximal femora in 38 (49%) women. Teenage physical activity, but not activity during other age periods, was associated with current aBMD at both sites (lumbar spine r = 0.31, P < 0.01; mean proximal femora r = 0.33, P < 0.01). Weight-bearing physical activity (WBPA) at age 12–18 years was the only predictor of current lumbar spine aBMD (R 2 = 0.110, P = 0.004). Current proximal femoral aBMD was positively predicted by physical activity at age 12–18 years and negatively predicted by current age (R 2 = 0.175, P = 0.001). Subjects above the median of teen WBPA had 5–8% higher current aBMD than those reporting less teen WBPA and were less likely to be classified with osteopenia or osteoporosis. Moderate physical activity during years of peak bone acquisition appears to have lasting benefits for lumbar spine and proximal femoral aBMD in postmenopausal women.
Exercise for optimising peak bone mass in women
Proceedings of the Nutrition Society, 2008
Physical activity is one of the major non-pharmacological methods for increasing and maintaining bone mineral density (BMD) and geometry. As such, it has an important role in maintaining peak bone mass and strength, thus reducing the risk of future osteoporotic fracture. However, not all exercise is effective, so a prescription in terms of optimal type, intensity, frequency and duration is required. Studies using animal models suggest that loading that is high in magnitude, rapidly applied and novel is most effective, whilst duration is less important beyond a threshold number of cycles. In human subjects cross-sectional studies comparing different athletic populations suggest that those who participate in high- or odd-impact sports have higher BMD; whilst impact exercise, strength training and brief high-impact-jump training interventions increase BMD in premenopausal women. In order to further elucidate exercise recommendations to optimise bone health in this population, the usefu...
A two-year program of aerobics and weight training enhances bone mineral density of young women
Journal of Bone and Mineral Research, 2009
Previous research suggests that physical activity may have a beneficial effect on bone mineral density (BMD) in women. This relationship was explored in a 2-year, randomized, intervention trial investigating the efficacy of exercise and calcium supplementation on increasing peak bone mass in young women. One hundred and twenty-seven subjects (ages of 20-35 years) were randomly assigned either to an exercise program that contained both aerobics and weight training components or to a stretching program. Calcium supplementation (up to 1500 mg/day including dietary intake) or placebo was given in a double-blinded design to all subjects. Spinal trabecular BMD was determined using quantitative computed tomography (QCT). Spinal integral, femoral neck, and trochanteric BMD were measured by dual X-ray absorptiometry (DXA) and calcaneal BMD by single photon absorptiometry (SPA). Fitness variables included maximal aerobic capacity (VOZmax), and isokinetic muscle performance of the trunk and thigh. Measurements were made at baseline, 1 year, and 2 years. Sixty-three subjects (32 exercise, 31 stretching) completed the study, and all the measured bone parameters indicated a positive influence of the exercise intervention. There were significant positive differences in BMD between the exercise and stretching groups for spinal trabecular (2.5%), femoral neck (2.4%), femoral trochanteric (23%), and calcaneal (6.4%) measurements. The exercise group demonstrated a significant gain in BMD for spinal integral (13 f 2.8%, p < 0.02), femoral trochanteric (2.6 f 6.1%,p < 0.05), and calcaneal (5.6 f 5. 1 ,~ < 0.01) measurements. In contrast to exercise, the calcium intervention had no positive effect on any of the bone parameters. In regard to fitness parameters, the exercise group completed the study with significant gains in VOZmax and isokinetic (peak torque) values for the knee flexion and extension and trunk extension. This study indicates that over a 2-year period, a combined regimen of aerobics and weight training has beneficial effects on BMD and fitness parameters in young women. However, the addition of daily calcium supplementation does not add significant benefit to the intervention.
Intensity of exercise is associated with bone density change in premenopausal women
Osteoporosis International, 2006
Introduction High-impact exercise is known to be beneficial for bones. However, the optimal amount of exercise is not known. The aim of the present study was to evaluate the association between the intensity of exercise and bone mineral density (BMD). Methods We performed a 12-month population–based trial with 120 women (aged 35–40 years) randomly assigned to an exercise group or to a control group. The intensity of the physical activity of 64 women was assessed with an accelerometer–based body movement monitor. The daily activity was analyzed at five acceleration levels (0.3–1.0 g, 1.1–2.4 g, 2.5–3.8 g, 3.9–5.3 g, and 5.4–9.2 g). BMD was measured at the hip, spine (L1–L4), and radius by dual-energy x–ray absorptiometry. The calcaneus was measured using quantitative ultrasound. Results Physical activity that induced acceleration levels exceeding 3.9 g correlated positively with the BMD change in the hip area (ppp Conclusion The intensity of exercise, measured as the acceleration level of physical activity, was significantly correlated with BMD changes. Bone stimulation is reached during normal physical exercise in healthy premenopausal women. In the hip area, the threshold level for improving BMD is less than 100 accelerations per day at levels exceeding 3.9 g.
Exercise Training and Bone Mineral Density
Quest, 1995
The effect of exercise training on total and regional bone mineral density (BMD) in postmenopausal women is reviewed. Several studies on the non-estrogenreplete postmenopausal population show 1-2% changes in regional BMD with one year of weight-bearing exercises. Studies of exercise training in the estrogenreplete postmenopausal population suggest large BMD changes. The long-term effect of exercise on the rate of loss in BMD after menopause and its effects on osteoporotic fractures is a critical area for future investigations. The focus of this article is on the effects of exercise training on regional and total bone mineral density (BMD) in postmenopausal women. Excellent review articles on physical activity and bone mineral density have been completed (Drinkwater, 1994a, 1994b; Forwood & Burr, 1993; Marcus et al., 1992; Snow-Harter & Marcus, 1991). Much less is known on the relationship of physical activity to bone fracture risk. Studies on premenopausal female adults have shown that participation in exercise programs for up to one year can increase the regional BMD from 1 to 3% (Gleeson, Protos, LeBlanc, Schneider, & Evans, 1990; Lohman et al., in press; Snow-Harter, Bouxsein, Lewis, Carter, & Marcus, 1992). While this effect is statistically significant, it is not likely to have major health benefits on the incidence of osteoporosis in the elderly. Studies are needed on how exercise programs affect the older populations, where the rate of bone mineral loss may be decreased by exercise, as well as in the adolescent population, where bone mineral development may be enhanced by exercise. Drinkwater (1994b) summarizes the status of the literature in this area as follows: "There are no prospective studies to document the effect of increased physical activity with a resultant increase in bone mass on the incidence of osteoporotic fractures" (p. 724).
Medicine & Science in Sports & Exercise
The purpose of this study was to evaluate whether premenopausal women's voluntary unsupervised aerobic and step training could maintain the skeletal benefits obtained by an 18-month supervised high-impact training, and if so, to what extent. Thirty women of the original 39 study subjects (i. e., persons who completed the preceding 18-month randomized training intervention and who volunteered to continue the training on their own for a further 8 months) and 19 women of the 45 original control subjects (i.e., persons who volunteered to continue as controls) were included. The study group trained an average of twice per week and the training consisted of regular aerobic and step classes provided by local fitness centers. Areal bone mineral density (BMD, g/cm2) was measured from the lumbar spine, femoral neck, trochanter area of the femur, distal femur, patella, proximal tibia, calcaneus, and dominant distal radius at baseline and after 18 and 26 months. During the extended 8-month follow-up, the BMD of the study group increased more at the femoral neck (the intergroup change was +0.9% at 18 months and +2.8% at 26 months, p = 0.004 for the change between 18 and 26 months) and remained at the 18-month level at the distal femur, patella, proximal tibia, and calcaneus. In these sites, the statistically significant changes during the entire 26 months of training were 1.7-4.0% in the training group as compared with the changes of -0.9-1.5% in the control group. In the lumbar spine, BMD decreased from the 18-month level in both groups. In conclusion, the significant BMD increases that were obtained by supervised 18-month high-impact training were effectively maintained with subsequent unsupervised regular aerobic and step classes (twice per week). The finding emphasizes the effectiveness and feasibility of self-controlled aerobic and step exercises in the primary prevention of osteoporosis among healthy premenopausal women.
The Effect of Physical Activity on Bone Accrual, Osteoporosis and Fracture Prevention
The Open Bone Journal, 2011
Background: Physical activity has been recommended for the prevention and even treatment of osteoporosis because it potentially can increase bone mass and strength during childhood and adolescence and reduce the risk of falling in older populations. However, few reports have systematically investigated the effect of physical activity on bone in men and women of different ages. Purpose: The goal of this study was to review the literature relating to the effect of physical activity on bone mineral density in men and women of various ages. Method: This review systematically evaluates the evidence for the effect of physical activity on bone mineral density. Cochrane and Medline databases were searched for relevant articles, and the selected articles were evaluated. Results: The review found evidence to support the effectiveness of weight bearing physical activity on bone accrual during childhood and adolescence. The effect of weight bearing physical activity was site-specific. In contrast, the role of physical activity in adulthood is primarily geared toward maintaining bone mineral density. The evidence for a protective effect of physical activity on bone is not as solid as that for younger individuals. Conclusions: The effect of weight bearing physical activity is seen in sites that are exposed to loading. There also seems to be a continuous adaptive response in bone to loading. Additional randomized, controlled studies are needed to evaluate the effect of physical activity in the elderly.
Bone, 1997
The association between sports participation during adolescence and peri-and postmenopausai bone mineral density (BMD) was examined among 2025 women aged 48-58 years. Adolescent recreational and competitive sporting activities were registered with a self-administered questionnaire. Altogether, 881 (43.5%) women stated that they had taken part in sports during their adolescence. BMD was measured using dual X-ray absorptiometry (DXA) in lumbar vertebrae 2-4 and the left femoral neck. The unadjusted BMD was 2.4% higher (/7 = 0.001) and the adjusted BMD was 1.4% higher in the spine (p = 0.015 after adjusting for age, weight, time from menopause to densitometry, and duration of estrogen replacement therapy) among women who had taken part in sports during their adolescence compared to women who had been inactive. There was no significant difference in femoral neck BMD between these groups. The results of this populationbased study suggest that intense recreational physical activity in adolescence could play some role in preventing axial osteoporosis in later life. (Bone 21:363-367; 1997) © 1997 by Elsevier Science Inc. All rights reserved.