***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: To assess age and gender differences in muscle strength , isometric , concentric ( Con ) , and eccentric ( Ecc ) peak torque was measured in the knee extensors at a slow ( 0.52 rad/s ) and fast ( 3.14 rad/s ) velocity in 654 subjects ( 346 men and 308 women , aged 20 - 93 yr ) from the Baltimore Longitudinal Study of Aging . Regression analysis revealed significant ( P < 0.001 ) age-related reductions in Con and Ecc peak torque for men and women at both velocities , but no differences were observed between the gender groups or velocities . Age explained losses in Con better than Ecc peak torque , accounting for 30 % ( Con ) vs. 19 % ( Ecc ) of the variance in men and 28 % ( Con ) vs. 11 % ( Ecc ) in women . To assess age and gender differences in the ability to store and utilize elastic energy , the stretch-shortening cycle was determined in a subset of subjects ( n = 47 ) . The older women ( mean age = 70 yr ) showed a significantly greater enhancement in the stretch-shortening cycle , compared with men of similar age ( P < 0.01 ) and compared with younger men and women ( each P < 0.05 ) . Both men and women showed significant declines in muscle quality for Con peak torque ( P < 0.01 ) , but no gender differences were observed . Only the men showed a significant decline in muscle quality ( P < 0.001 ) for Ecc peak torque . Thus both men and women experience age-related losses in isometric , Con , and Ecc knee extensor peak torque ; however , age accounted for less of the variance in Ecc peak torque in women , and women tend to better preserve muscle quality with age for Ecc peak torque . In addition , older women have an enhanced capacity to store and utilize elastic energy compared with similarly aged men as well as with younger women and men To determine whether 10 weeks of whole-body vibration ( WBV ) training has a significant effect on strength , muscle mass , muscle power , and mobility in older women , 26 subjects were r and omly assigned to a  WBV training group ( n=13 ; mean age 79 years ) and a control ( CON ) group ( n=13 ; mean age 76 years ) . Maximal voluntary isometric contraction ( MVIC ) increased 38.8 % in the WBV group , without changes in the CON group . Electromyographic activity of the vastus medialis ( VM ) , the vastus lateralis , and the biceps femoris ( BF ) did not change in either group . Thigh muscle cross-sectional area increased significantly after training in VM ( 8.7 % ) and BF ( 15.5 % ) . Muscle power at 20 % , 40 % , and 60 % MVIC decreased from pre-test to post-test in the CON group ; however , WBV training prevented the decrease in the WBV group . Consequently , mobility , measured by the Timed Up and Go test , increased significantly after training ( 9.0 % ) only in the WBV group . Ten weeks of lower limb WBV training in older women produces a significant increase in muscle strength induced by thigh muscle hypertrophy , with no change in muscle power . The adaptations to WBV found in the present study may be of use in counteracting the loss of muscle strength and mobility associated with age-induced sarcopenia This study examined the correlations between isokinetic muscle strength of knee and elbow flexors and extensors with vertebral and femoral bone mineral density in a population of 106 women between the ages of 44 and 87 years . The absolute value of muscle strength correlated significantly with bone mineral density ; muscle strength of the upper limb appeared to be more closely correlated with bone mass , while muscle strength in the lower limb was more specific for femoral mineral bone density . The most important finding that these results demonstrated was a concomitant decline in muscle strength of the upper limb and bone mineral density between the 5th and 6th decades . In contrast , they also showed a decline in muscle strength of the lower limbs after the 6th decade , occurring before the decline in bone mineral density observed between the 7th and 8th decades . From these results it would appear that other studies are required to examine the relationship between the essentially hormonal role in postmenopausal decline in muscle strength and the decline in physical activity during the senile period . These elements are important because they must be taken into account in physical exercise programmes design ed to prevent osteoporosis The aim was to study whether whole body vibration ( WBV ) combined with conventional resistance training ( CRT ) induces a higher increase in neuromuscular and hormonal measures compared with CRT or WBV , respectively . Twenty-eight young men were r and omized in three groups ; squat only ( S ) , combination of WBV and squat ( S+V ) and WBV only ( V ) . S+V performed six sets with eight repetitions with corresponding eight repetition maximum ( RM ) loads on the vibrating platform , whereas S and V performed the same protocol without WBV and resistance , respectively . Maximal isometric voluntary contraction ( MVC ) with electromyography ( EMG ) measurements during leg press , counter movement jump ( CMJ ) measures ( mechanical performance ) including jump height , mean power ( Pmean ) , peak power ( Ppeak ) and velocity at Ppeak ( Vppeak ) and acute hormonal responses to training sessions were measured before and after a 9-week training period . ANOVA showed no significant changes between the three groups after training in any neuromuscular variable measured [ except Pmean , S higher than V ( P<0.05 ) ] . However , applying t tests within each group revealed that MVC increased in S and S+V after training ( P<0.05 ) . Jump height , Pmean and Ppeak increased only in S , concomitantly with increased Vppeak in all groups ( P<0.05 ) . Testosterone increased during training sessions in S and S+V ( P<0.05 ) . Growth hormone ( GH ) increased in all groups but S+V showed higher responses than S and V ( P<0.05 ) . Cortisol increased only in S+V ( P<0.05 ) . We conclude that combined WBV and CRT did not additionally increase MVC and mechanical performance compared with CRT alone . Furthermore , WBV alone did not increase MVC and mechanical performance in spite of increased GH Beck BR , Norling TL : The effect of 8 mos of twice-weekly low- or higher intensity whole body vibration on risk factors for postmenopausal hip fracture . Objective : Whole body vibration is a potential therapy for age-related loss of musculoskeletal competence . Vibration has improved bone in animal models , but evidence in humans is limited . Relative efficacy of low- vs. high-intensity whole body vibration is also unknown . Our goal was to observe the effect of brief low- and higher intensity whole body vibration on risk factors for hip fracture in postmenopausal women . Design : We used an 8-mo r and omized controlled trial design to examine the influence of twice-weekly low-intensity whole body vibration ( 15 mins , 30 Hz , 0.3 g ) or higher intensity whole body vibration ( 2 × 3 mins , 12.5 Hz , 1 g ) on anthropometrics , bone ( whole body , hip , spine , forearm , and heel ) , muscle ( wall squat and chair rise ) , and balance ( t and em walk and single leg stance ) . Physical activity , daily calcium , and compliance were recorded . Effects were examined by repeated- measures analysis of covariance , controlling for age , height , weight , calcium , physical activity , compliance , and baseline values . Results : Forty-seven women ( 71.5 ± 9.0 yrs ) completed the trial . There were no between-group differences in any measure at 8 mos , but within-group effects were evident . Controls lost bone at the trochanter ( −6 % , P = 0.03 ) and lumbar spine ( −6.6 % , P = 0.02 ) , whereas whole body vibration groups did not . Whole body vibration subjects improved wall squat ( up to 120 % , P = 0.004 ) and chair rise performance ( up to 10.5 % , P = 0.05 ) . Conclusions : Eight mos of twice-weekly whole body vibration may reduce bone loss at the hip and spine and improve lower limb muscle function . These changes may translate to a decreased risk of falls and hip fracture PURPOSE The aim of this study was to investigate and to compare the effect of a 12-wk period of whole-body vibration training and resistance training on human knee-extensor strength . METHODS Sixty-seven untrained females ( 21.4 + /- 1.8 yr ) participated in the study . The whole-body vibration group ( WBV , N = 18 ) and the placebo group ( PL , N = 19 ) performed static and dynamic knee-extensor exercises on a vibration platform . The acceleration of the vibration platform was between 2.28 g and 5.09 g , whereas only 0.4 g for the PL condition . Vibration ( 35 - 40 Hz ) result ed in increased EMG activity , but the EMG signal remained unchanged in the PL condition . The resistance-training group ( RES , N = 18 ) trained knee extensors by dynamic leg-press and leg-extension exercises ( 10 - 20 RM ) . All training groups exercised 3x wk-1 . The control group ( CO , N = 12 ) did not participate in any training . Pre- and postisometric , dynamic , and ballistic knee-extensor strength were measured by means of a motor-driven dynamometer . Explosive strength was determined by means of a counter-movement jump . RESULTS Isometric and dynamic knee-extensor strength increased significantly ( P < 0.001 ) in both the WBV group ( 16.6 + /- 10.8 % ; 9.0 + /- 3.2 % ) and the RES group ( 14.4 + /- 5.3 % ; 7.0 + /- 6.2 % ) , respectively , whereas the PL and CO group showed no significant ( P > 0.05 ) increase . Counter-movement jump height enhanced significantly ( P < 0.001 ) in the WBV group ( 7.6 + /- 4.3 % ) only . There was no effect of any of the interventions on maximal speed of movement , as measured by means of ballistic tests . CONCLUSIONS WBV , and the reflexive muscle contraction it provokes , has the potential to induce strength gain in knee extensors of previously untrained females to the same extent as resistance training at moderate intensity . It was clearly shown that strength increases after WBV training are not attributable to a placebo effect Background : It has been unclear which training mode is most effective and feasible for improving physical performance in the risk group of prefrail community-dwelling older adults . Objective : The purpose of the present study was to compare the effects of strength training ( ST ) versus power training ( PT ) on functional performance in prefrail older adults . This study was registered at clinical trials.gov as NCT00783159 . Methods : 69 community-dwelling older adults ( > 65 years ) who were prefrail according to the definition of Fried were included in a 12-week exercise program . The participants were r and omized into an ST group , a PT group and a control group . All participants were supplemented with vitamin D3 orally before entering the intervention period . The primary outcome was the global score on the Short Physical Performance Battery ( SPPB ) . Secondary outcomes were muscle power , appendicular lean mass ( aLM ) measured by dual energy X-ray absorptiometry and self-reported functional deficits ( Short Form of the Late-Life Function and Disability Instrument , SF-LLFDI ) . Results : Regarding changes in the SPPB score during the intervention , significant heterogeneity between the groups was observed ( p = 0.023 ) . In pair-wise comparisons , participants in both training groups significantly ( PT : p = 0.012 , ST : 0.009 ) increased their SPPB score ( PT : Δmean = 0.8 , ST : Δmean = 1.0 ) compared to the control group , with no statistical difference among training groups ( p = 0.301 ) . No statistical differences were found in changes in aLM ( p = 0.769 ) , muscle power ( p = 0.308 ) and SF-LLFDI ( p = 0.623 ) between the groups . Muscle power significantly increased ( p = 0.017 ) under vitamin D3 intake . Conclusions : In prefrail community-dwelling adults , PT is not superior to ST , although both training modes result ed in significant improvements in physical performance . With regard to dropout rates , ST appears to be advantageous compared to PT . The high prevalence of vitamin D3 deficiency and the slight improvement of physical performance under vitamin D3 supplementation among study participants underline the relevance of this approach in physical exercise interventions UNLABELLED High-frequency mechanical strain seems to stimulate bone strength in animals . In this r and omized controlled trial , hip BMD was measured in postmenopausal women after a 24-week whole body vibration ( WBV ) training program . Vibration training significantly increased BMD of the hip . These findings suggest that WBV training might be useful in the prevention of osteoporosis . INTRODUCTION High-frequency mechanical strain has been shown to stimulate bone strength in different animal models . However , the effects of vibration exercise on the human skeleton have rarely been studied . Particularly in postmenopausal women-who are most at risk of developing osteoporosis-r and omized controlled data on the safety and efficacy of vibration loading are lacking . The aim of this r and omized controlled trial was to assess the musculoskeletal effects of high-frequency loading by means of whole body vibration ( WBV ) in postmenopausal women . MATERIAL S AND METHODS Se 
    Output:
    
No significant improvements in lean mass with WBVT were found in postmenopausal women .
In addition , there was no significant difference in lean mass between WBVT and control postmenopausal women .
Conclusions : This meta- analysis demonstrated that WBVT alone may not be a sufficient stimulus to increase lean mass  in postmenopausal women .