***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Physical exercise has a favorable impact on bones , but optimum training strategies are still under discussion . In this study , we compared the effect of slow and fast resistance exercises on various osteodensitometric parameters .  Fifty-three postmenopausal women were r and omly assigned to a strength training ( ST ) or a power training group ( PT ) . Both groups carried out a progressive resistance training , a gymnastics session , and a home training over a period of 12 mo . During the resistance training , the ST group used slow and the PT group fast movements ; otherwise there were no training differences . All subjects were supplemented with Ca and vitamin D. At baseline and after 12 mo , bone mineral density ( BMD ) was measured at the lumbar spine , proximal femur , and distal forearm by dual-energy X-ray absorptiometry . We also measured anthropometric data and maximum static strength . Frequency and grade of pain were assessed by question naire . After 12 mo , significant between-group differences were observed for BMD at the lumbar spine ( P < 0.05 ) and the total hip ( P < 0.05 ) . Whereas the PT group maintained BMD at the spine ( + 0.7 + /- 2.1 % , not significant ) and the total hip ( 0.0 + /- 1.7 % , not significant ) , the ST group lost significantly at both sites ( spine : -0.9 + /- 1.9 % ; P < 0.05 ; total hip : -1.2 + /- 1.5 % ; P < 0.01 ) . No significant between-group differences were observed for anthropometric data , maximum strength , BMD of the forearm , or frequency and grade of pain . These findings suggest that power training is more effective than strength training in reducing bone loss in postmenopausal women Summary This study showed that combination of strength , balance , agility and jumping training prevented functional decline and bone fragility in home-dwelling elderly women . The finding supports the idea that it is possible to maintain good physical functioning by multi-component exercise program and thus postpone the age-related functional problems . Introduction This 1-year r and omized , controlled exercise intervention trial assessed the effects of two different training programs and their combination on physical functioning and bone in home-dwelling elderly women . Methods One hundred and forty-nine healthy women aged 70–78 years were r and omly assigned into : group 1—resistance training ( RES ) , group 2—balance-jumping training ( BAL ) , group 3—combination of resistance and balance-jumping training ( COMB ) , and group 4—controls ( CON ) . Self-rated physical functioning , leg extensor force , dynamic balance , and bone mass and structure were measured . Results Self-rated physical functioning improved in the COMB group , but was reduced in the CON group ; the mean inter-group difference was 10 % ( 95 % CI : 0–22 % ) . Mean increase in the leg extensor force was higher in the RES ( 14 % ; 4–25 % ) and COMB ( 13 % ; 3–25 % ) compared with the CON groups . Dynamic balance improved in the BAL ( 6 % ; 1–11 % ) and in the COMB ( 8 % ; 3–12 % ) groups . There were no inter-group differences in BMC at the proximal femur . In those COMB women who trained at least twice a week , the tibial shaft structure weakened 2 % ( 0–4 % ) less than those in the CON group . Conclusions Strength , balance , agility , and jumping training ( especially in combination ) prevented functional decline in home-dwelling elderly women . In addition , positive effects seen in the structure of the loaded tibia indicated that exercise may also play a role in preventing bone fragility STUDY OBJECTIVE To assess the effect of weight-bearing exercise training and subsequent detraining on lumbar bone mineral content in postmenopausal women . DESIGN Non-r and omized , controlled , short-term ( 9 months ) trial and long-term ( 22 months ) exercise training and detraining ( 13 months ) . SETTING Section of applied physiology at a university school of medicine . PATIENTS Thirty-five healthy , sedentary postmenopausal women , 55 to 70 years old . All women completed the study . There was 90 % compliance with exercise training . INTERVENTIONS All women were given calcium , 1500 mg daily . The exercise group did weight-bearing exercise ( walking , jogging , stair climbing ) at 70 % to 90 % of maximal oxygen uptake capacity for 50 to 60 min , 3 times weekly . MEASUREMENTS AND MAIN RESULTS Bone mineral content increased 5.2 % ( 95 % confidence interval [ CI ] , 2.0 % to 8.4 % ; P = 0.0037 ) above baseline after short-term training whereas there was no change ( -1.4 % ) in the control group . After 22 months of exercise , bone mineral content was 6.1 % ( 95 % CI , 3.9 % to 8.3 % above baseline ; P = 0.0001 ) in the long-term training group . After 13 months of decreased activity , bone mass was 1.1 % above baseline in the detraining group . CONCLUSIONS Weight-bearing exercise led to significant increases above baseline in bone mineral content which were maintained with continued training in older , postmenopausal women . With reduced weight-bearing exercise , bone mass reverted to baseline levels . Further studies are needed to determine the threshold exercise prescription that will produce significant increases in bone mass The aim was to assess the effects of resistance training and vitamin D supplementation on physical performance of healthy elderly subjects . Ninety-six subjects , aged 70 years or more with 25 OH vitamin D levels of 16 ng/ml or less , were r and omized to a  resistance training or control group . Trained and control groups were further r and omized to receive in a double blind fashion , vitamin D 400 IU plus 800 mg of calcium per day or calcium alone . Subjects were followed for nine months . Serum 25 OH vitamin D increased from 12.4+/-2.2 to 25.8+/-6.5 ng/ml among subjects supplemented with vitamin D. Trained subjects had significant improvements in quadriceps muscle strength , the short physical performance test and timed up and go . The latter improved more in trained subjects supplemented with vitamin D. At the end of the follow up , gait speed was higher among subjects supplemented with vitamin ( whether trained or not ) than in non-supplemented subjects ( 838+/-147 and 768+/-127 m/12 min , respectively , p=0.02 ) . Romberg ratio was lower among supplemented controls than non-supplemented trained subjects ( 128+/-40 % and 144+/-37 % , respectively , p=0.05 ) . In conclusion , vitamin D supplementation improved gait speed and body sway , and training improved muscle strength Background The purpose of this study was to evaluate the role of study quality assessment of primary studies in cancer practice guidelines . Methods Reliable and valid study quality  assessment scales were sought and applied to published reports of trials included in systematic review s of cancer guidelines . Sensitivity analyses were performed to evaluate the relationship between quality scores and pooled odds ratios ( OR ) for mortality and need for blood transfusion .  Results Results found that that whether trials were classified as high or low quality depended on the scale used to assess them . Although the results of the sensitivity analyses found some variation in the ORs observed , the confidence intervals ( CIs ) of the pooled effects from each of the analyses of high quality trials overlapped with the CI of the pooled odds of all trials . Quality score was not predictive of pooled ORs studied here . Conclusions Had sensitivity analyses based on study quality been conducted prospect ively , it is highly unlikely that different conclusions would have been found or that different clinical recommendations would have emerged in the guidelines OBJECTIVE To investigate the effect of a 2-year vigorous , combined high-impact , strength , and endurance training program on bone mineral density ( BMD ) determined by dual-energy x-ray absorptiometry ( DXA ) , quantitative computed tomography ( QCT ) , and ultrasound in early postmenopausal women with osteopenia . DESIGN Nonr and omized controlled trial , reporting 1-year data . SETTING Community . PARTICIPANTS Early postmenopausal ( 1 - 8y postmenopausal ) osteopenic women ( DXA T score at lumbar spine or total hip between -1 and -2.5 st and ard deviations ) . The exercise group ( n=59 ; mean age , 55.1+/-3.4y ) and control group ( n=41 ; mean age , 55.9+/-3.1y ) were recruited from community registers . INTERVENTION Fourteen months of exercise training , with 2 joint sessions and 2 additional home training sessions . Exercise and control groups were supplemented individually with calcium and cholecalciferol up to 1500 mg of calcium and 500IU of vitamin D per day . MAIN OUTCOMES MEASURES BMD at the lumbar spine and total hip measured by DXA , isometric maximum strength , and maximal oxygen consumption ( VO2max ) during a stepwise running test to exhaustion . RESULTS Bone density increased significantly at the lumbar spine for the exercise group ( 1.3 % , P<.001 ) and decreased in the control group ( -1.2 % , P<.01 ) . Differences at the total hip ( -0.3 % , not significant vs -0.8 % , P<.05 ) and the femoral neck ( -0.8 % , P<.05 vs -1.8 % , P<.001 ) were nonsignificant . Changes in isometric maximum strength were significant for each region ( grip strength , trunk flexors and extensors , hip flexors , leg adductors and abductors , arm flexors and extensors ) in the exercise group ( 11%-39 % ) compared with nonrelevant changes ( -1.1 % to 3.9 % ) in the control group . Between-group differences were significant ( P<.01-.001 ) for all strength parameters . VO2max increased significantly by 11 % ( P<.001 ) in the exercise group but decreased in the control group by 4 % ( P<.05 ) while showing significant between-group differences . CONCLUSION High-intensity exercise training can have a positive influence on bone density in early postmenopausal osteopenic women Abstract Objective : To determine the effect of four monthly vitamin D supplementation on the rate of fractures in men and women aged 65 years and over living in the community . Design : R and omised double blind controlled trial of 100 000 IU oral vitamin D3 ( cholecalciferol ) supplementation or matching placebo every four months over five years . Setting and participants : 2686 people ( 2037 men and 649 women ) aged 65 - 85 years living in the general community , recruited from the British doctors register and a general practice register in Suffolk . Main outcome measures : Fracture incidence and total mortality by cause . Results : After five years 268 men and women had incident fractures , of whom 147 had fractures in common osteoporotic sites ( hip , wrist or forearm , or vertebrae ) . Relative risks in the vitamin D group compared with the placebo group were 0.78 ( 95 % confidence interval 0.61 to 0.99 , P=0.04 ) for any first fracture and 0.67 ( 0.48 to 0.93 , P=0.02 ) for first hip , wrist or forearm , or vertebral fracture . 471 participants died . The relative risk for total mortality in the vitamin D group compared with the placebo group was 0.88 ( 0.74 to 1.06 , P=0.18 ) . Findings were consistent in men and women and in doctors and the general practice population . Conclusion : Four monthly supplementation with 100 000 IU oral vitamin D may prevent fractures without adverse effects in men and women living in the general community . What is already known in this topic Vitamin D and calcium supplements are effective in preventing fractures in elderly women Whether isolated vitamin D supplementation prevents fractures is not clear What this paper adds Four monthly oral supplementation with 100 000 IU vitamin D reduces fractures in men and women aged over 65 living in the general community  Total fracture incidence was reduced by 22 % and fractures in major osteoporotic sites by 33 A r and omized , controlled , single-blinded 25-wk prospect i ve study was conducted to compare the effects of group-based resistance and agility training on bone , as measured by both dual-energy X-ray absorptiometry ( DXA ) and peripheral quantitative computed tomography ( pQCT ) , in older women with low bone mass . Ninety-eight community-dwelling women aged 75 - 85 yr were r and omized to one of three experimental groups : resistance training ( n = 32 ) , agility training ( n = 34 ) , or stretching ( sham exercise ) ( n = 32 ) . Total hip , femoral neck , and trochanteric bone mineral density ( BMD ) were measured by DXA . Peripheral QCT measurements were performed at the tibia and radius . The pQCT outcome measures at the shaft regions were cortical bone content , cortical bone cross-sectional area , cortical bone density , and density-weighted polar section modulus ( SSI ) . The pQCT outcome measures at the distal sites were total bone content , total bone cross-sectional area , and total bone density . At trial completion , the agility training group significantly increased cortical bone 
    Output:
    
Using a systematic review and meta- analysis , we found a decrease in bone loss through the maintenance of cortical and trabecular volumetric bone mineral density ( BMD ) .
Studies with longer duration s of exercise ( 12 months ) and those in early postmenopausal women showed significant changes in CvBMD at the tibial shaft .
Conclusions We conclude that exercise in postmenopausal women may decrease bone loss by maintaining cortical and trabecular volumetric BMD .