human
***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: Summary Fall prevention is a key strategy for reducing  osteoporotic fractures . We investigated the association between vitamin D receptor ( VDR ) polymorphisms and reported  falls in postmenopausal women . Bsm1 polymorphisms were associated with falls , balance and muscle power measurements . These results may explain some of the excess fracture risk associated with VDR in some studies . Introduction Fall prevention is a key strategy for reducing osteoporotic fractures . It has been suggested that vitamin D supplementation may reduce the incidence of falls by reducing body sway and increasing muscle power . The vitamin D receptor gene is a well-studied c and i date gene for osteoporosis . We investigated the association between VDR polymorphisms and reported  falls in postmenopausal women . Methods Falls data were collected in two separate population cohorts . Five polymorphisms of the VDR gene were analysed ( Cdx-2 , Fok-1 , BsmI , Taq1 and Apa1 ) in the Aberdeen Prospect i ve Osteoporosis Screening Study ( APOSS ) cohort . Results found in APOSS were then vali date d in an independent cohort — the Osteoporosis and Ultrasound ( OPUS ) study ( Bsm1 and Fok1 only ) , where muscle power and balance were also measured . Results Carriers of the ‘ B ’ allele ( Bsm1 ) showed an increased risk for falls . In APOSS , this was statistically significant for visit 3 multiple falls ( p = 0.047 ) and for recurrent falls ( p = 0.043 ) . Similar results were found in OPUS for visit 1 falls ( p = 0.025 ) and visit 1 multiple falls ( p = 0.015 ) . Bsm1 polymorphisms were also associated with balance and muscle power measurements . Conclusions In conclusion , these results demonstrate an association between the Bsm1 polymorphism and risk of falling that may explain some of the excess fracture risk associated with VDR in some studies OBJECTIVE To test the efficacy of high-velocity training in healthy older persons . DESIGN A 12-week r and omized trial , with subjects blocked for gender and residence , comparing high-velocity resistance training with a self-paced walking program . SETTING Retirement community . PARTICIPANTS Forty-three volunteers over the age of 70 years . INTERVENTION Power group : high-velocity leg exercises 3 times weekly with weekly increases in resistance combined with 45 minutes of moderate , nonresistance exercise weekly . Walking group : moderate intensity exercise 30 minutes daily , 6 days weekly . MAIN OUTCOME MEASURES Variables measured included leg press peak power and leg extensor strength . Functional performance outcomes included : 6-minute walk distance , Short Physical Performance Battery , Physical Performance Test , and Medical Outcomes Study Short-Form Health Survey . RESULTS Peak power improved 22 % ( p = .004 ) in the power group ( 3.7 + /- 1.0 W/kg to 4.5 + /- 1.4 W/kg ) but did not change in the walking group ( 3.99 + /-.76 W/kg to 3.65 + /-.94 W/kg ) . Leg extensor power at resistance of 50 % , 60 % , and 70 % of body weight increased 50 % , 77 % , and 141 % , respectively , in the power group ( p < .0001 , repeated- measures analysis of variance ) . Strength improved 22 % in the power-trained individuals and 12 % in the walkers ( p < .0001 ) . Training did not improve functional task performance in either group . One subject developed a radiculopathy during training . CONCLUSIONS Resistance training focusing on speed of movement improved leg power and maximal strength substantially , but did not improve functional performance in healthy high-functioning older volunteers Sayers , SP and Gibson , K. A comparison of high-speed power training and traditional slow-speed resistance training in older men and women . J Strength Cond Res 24(12 ) : 3369 - 3380 , 2010-Muscle power , the product of force × velocity , is a critical determinant of function in older adults . Resistance training ( RT ) at high speed has been shown to improve peak muscle power in this population ; however , different functional tasks may benefit from the improvement of power at values other than “ peak ” values , for example , tasks that require a greater velocity component or a greater force component . This study compared the effect of high-speed RT on muscle performance ( peak power [ PP ] and its components [ PP force and PP velocity ] and overall peak velocity [ VEL ] ) across a broad range of external resistances . Thirty-eight older men and women were r and omized  to high-speed power training at 40 % of the 1-repetition maximum ( 1RM ) ( n = 13 [ 74.1 ± 6.4 years ] ) ; traditional RT at 80 % 1RM ( n = 13 [ 70.1 ± 7.0 years ] ) ; or control ( n = 12 [ 72.8 ± 4.1 years ] ) . Measures of muscle performance were obtained at baseline and after the 12-week training intervention . Muscle power and 1RM strength improved similarly with both high-speed and traditional slow-speed RT . However , speed-related muscle performance characteristics , PP velocity and overall VEL , were most positively impacted by high-speed power training , especially at lower external resistances . Because gains in speed-related measures with high-speed training compared to traditional RT do not come at the expense of other muscle performance outcomes , we recommend using an RT protocol in older adults that emphasizes high-speed movements at low external resistances We examined whether high-speed power training ( HSPT )  improved muscle performance and braking speed using a driving simulator . 72 older adults ( 22 m , 50 f ; age = 70.6 ± 7.3 yrs ) were r and omized to HSPT at 40 % one-repetition maximum ( 1RM ) ( HSPT : n = 25 ; 3 sets of 12–14 repetitions ) , slow-speed strength training at 80%1RM ( SSST : n = 25 ; 3 sets of 8–10 repetitions ) , or control ( CON : n = 22 ; stretching ) 3 times/week for 12 weeks . Leg press and knee extension peak power , peak power velocity , peak power force/torque , and braking speed were obtained at baseline and 12 weeks . HSPT  increased peak power and peak power velocity across a range of external resistances ( 40–90 % 1RM ; P < 0.05 ) and improved braking speed ( P < 0.05 ) . Work was similar between groups , but perceived exertion was lower in HSPT ( P < 0.05 ) . Thus , the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST Background Slow gait is common in dementia , but it remains unknown whether the slowing happens many years prior to dementia onset . We therefore examined the relationship between slow baseline gait speed ( GS ) , change in GS , and the hazard of incident dementia  in a community dwelling of elderly people . Methods A total of 3,663 participants dementia-free at baseline ( mean age , 73.5 years ) were followed up for 9 years from a prospect i ve cohort ( Three-City study , France ) for incident dementia ( all-cause , Alzheimer 's disease , vascular dementia , and other causes ) .  GS  over 6 m was assessed 4 times over the follow-up using two photoelectric cells . We used a multistate model to estimate the hazard ratio ( HR ) of dementia for baseline GS and tested a washout period of 4 to 7 years . The role of GS change between 65 and 85 years was examined using linear mixed models and joint models for survival and longitudinal data . Results A total of 296 participants developed dementia  during the follow-up . In age/sex-adjusted models , 1-SD ( 0.204 m/s ) lower GS was associated with an increased hazard of dementia ( HR = 1.59 , 95 % confidence interval [ CI ] = 1.39 , 1.81 , p < .001 ) , with associations evident when gait assessment s were taken from 4 years ( HR = 1.46 ; CI = 1.26 , 1.68 ) and 7 years ( HR=1.30 ; CI = 1.00 , 1.70 ) prior to dementia onset . Independently of baseline GS , those with a steeper decline had a higher hazard of dementia ( HR per 1 SD [ 0.007 m/s/year ] decrease = 3.39 [ 1.37 - 8.43 ] , p = .009 ) . Conclusions Gait is slower up to 7 years prior to clinical onset of dementia . Decline in GS is also more accelerated , suggesting strong links between cognitive and motor function in older adults Context : Findings of studies of testosterone ’s effects on muscle strength and physical function  in older men have been inconsistent ; its effects on muscle power and fatigability have not been studied . Objective : To determine the effects of testosterone administration for 3 years in older men on  muscle strength , power , fatigability , and physical function . Design , Setting , and Participants : This was a double-blind , placebo-controlled , r and omized trial of healthy men ≥60 years old with total testosterone levels of 100 to 400 ng/dL or free testosterone levels < 50 pg/mL. Interventions : R and om assignment to 7.5 g of 1 % testosterone or placebo gel daily for 3 years . Outcome Measures : Loaded and unloaded stair-climbing power , muscle strength , power , and fatigability in leg press and chest press exercises , and lean mass at baseline , 6 , 18 , and 36 months . Results : The groups were similar at baseline . Testosterone administration for 3 years was associated with significantly greater performance in unloaded and loaded stair-climbing power  than placebo ( mean estimated between-group difference , 10.7 W [ 95 % confidence interval ( CI ) , −4.0 to 25.5 ] , P = 0.026 ; and 22.4 W [ 95 % CI , 4.6 to 40.3 ] , P = 0.027 ) , respectively . Changes in chest-press strength ( estimated mean difference , 16.3 N ; 95 % CI , 5.5 to 27.1 ; P < 0.001 ) and power ( mean difference 22.5 W ; 95 % CI , 7.5 to 37.5 ; P < 0.001 ) , and leg-press power were significantly greater in men r and omized to testosterone than in those r and omized to  placebo . Lean body mass significantly increased more in the testosterone group . Conclusion : Compared with placebo , testosterone replacement in older men for 3 years was associated with modest but significantly greater improvements in stair-climbing power , muscle mass , and power . Clinical meaningfulness of these treatment effects and their impact on disability in older adults with functional limitations remains to be studied BACKGROUND Muscle power ( force x velocity ) recedes at a faster rate than strength with age and may also be a stronger predictor of fall risk and functional decline . The optimal training paradigm for improving muscle power in older adults is not known , although some literature suggests high velocity , low load training is optimal in young adults . METHODS One hundred twelve healthy older adults ( 69 + /- 6 years ) were r and omly assigned to either explosive resistance training at 20 % ( G20 ) , 50 % ( G50 ) , or 80 % ( G80 ) one repetition maximum ( 1RM ) for 8 - 12 weeks or to a nontraining control group ( CON ) . Participants trained twice per week ( five exercises ; three sets of eight rapidly concentric and slow eccentric repetitions ) using pneumatic resistance machines . Repeated- measures analysis of variance and covariance ( ANOVA and ANCOVA ) were used to determine the effects of training . RESULTS Average peak power increased significantly and similarly in G80 ( 14 + /- 8 % ) , G50 ( 15 + /- 9 % ) , and G20 ( 14 + /- 6 % ) compared to CON ( 3 + /- 6 % ) ( p < .0001 ) . By contrast , a positive dose-response relationship with training intensity was observed for relative changes in average strength ( r = .40 , p = .0009 ) and endurance ( r = .43 , p = .0005 ) . Average strength increased in G80 ( 20 + /- 7 % ) , G50 ( 16 + /- 7 % ) , and G20 ( 13 + /- 7 % ) compared to CON ( 4 + /- 4 % ) ( p < .0001 ) . Average muscle endurance increased in G80 ( 185 + /- 126 % , p < .0001 ) , G50 ( 103 + /- 75 % , p = .0004 ) , and G20 ( 82 + /- 57 % , p = .0078 ) compared to CON ( 28 + /- 29 % ) . CONCLUSION Peak muscle power may be improved similarly using light , moderate , or heavy resistances , whereas there is a dose-response relationship between training intensity and muscle strength and endurance changes . Therefore , using heavy loads during explosive resistance training may be the most effective strategy to achieve simultaneous improvements in muscle strength , power , and endurance in older adults Improving muscle strength and power may mitigate the effects of sarcopenia , but it is unknown if this improves an older adult ’s 
    Output:
    
agent
Finally , muscle power testing was found to be safe in older people with a broad range of health and functional states
***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: Summary Fall prevention is a key strategy for reducing  osteoporotic fractures . We investigated the association between vitamin D receptor ( VDR ) polymorphisms and reported  falls in postmenopausal women . Bsm1 polymorphisms were associated with falls , balance and muscle power measurements . These results may explain some of the excess fracture risk associated with VDR in some studies . Introduction Fall prevention is a key strategy for reducing osteoporotic fractures . It has been suggested that vitamin D supplementation may reduce the incidence of falls by reducing body sway and increasing muscle power . The vitamin D receptor gene is a well-studied c and i date gene for osteoporosis . We investigated the association between VDR polymorphisms and reported  falls in postmenopausal women . Methods Falls data were collected in two separate population cohorts . Five polymorphisms of the VDR gene were analysed ( Cdx-2 , Fok-1 , BsmI , Taq1 and Apa1 ) in the Aberdeen Prospect i ve Osteoporosis Screening Study ( APOSS ) cohort . Results found in APOSS were then vali date d in an independent cohort — the Osteoporosis and Ultrasound ( OPUS ) study ( Bsm1 and Fok1 only ) , where muscle power and balance were also measured . Results Carriers of the ‘ B ’ allele ( Bsm1 ) showed an increased risk for falls . In APOSS , this was statistically significant for visit 3 multiple falls ( p = 0.047 ) and for recurrent falls ( p = 0.043 ) . Similar results were found in OPUS for visit 1 falls ( p = 0.025 ) and visit 1 multiple falls ( p = 0.015 ) . Bsm1 polymorphisms were also associated with balance and muscle power measurements . Conclusions In conclusion , these results demonstrate an association between the Bsm1 polymorphism and risk of falling that may explain some of the excess fracture risk associated with VDR in some studies OBJECTIVE To test the efficacy of high-velocity training in healthy older persons . DESIGN A 12-week r and omized trial , with subjects blocked for gender and residence , comparing high-velocity resistance training with a self-paced walking program . SETTING Retirement community . PARTICIPANTS Forty-three volunteers over the age of 70 years . INTERVENTION Power group : high-velocity leg exercises 3 times weekly with weekly increases in resistance combined with 45 minutes of moderate , nonresistance exercise weekly . Walking group : moderate intensity exercise 30 minutes daily , 6 days weekly . MAIN OUTCOME MEASURES Variables measured included leg press peak power and leg extensor strength . Functional performance outcomes included : 6-minute walk distance , Short Physical Performance Battery , Physical Performance Test , and Medical Outcomes Study Short-Form Health Survey . RESULTS Peak power improved 22 % ( p = .004 ) in the power group ( 3.7 + /- 1.0 W/kg to 4.5 + /- 1.4 W/kg ) but did not change in the walking group ( 3.99 + /-.76 W/kg to 3.65 + /-.94 W/kg ) . Leg extensor power at resistance of 50 % , 60 % , and 70 % of body weight increased 50 % , 77 % , and 141 % , respectively , in the power group ( p < .0001 , repeated- measures analysis of variance ) . Strength improved 22 % in the power-trained individuals and 12 % in the walkers ( p < .0001 ) . Training did not improve functional task performance in either group . One subject developed a radiculopathy during training . CONCLUSIONS Resistance training focusing on speed of movement improved leg power and maximal strength substantially , but did not improve functional performance in healthy high-functioning older volunteers Sayers , SP and Gibson , K. A comparison of high-speed power training and traditional slow-speed resistance training in older men and women . J Strength Cond Res 24(12 ) : 3369 - 3380 , 2010-Muscle power , the product of force × velocity , is a critical determinant of function in older adults . Resistance training ( RT ) at high speed has been shown to improve peak muscle power in this population ; however , different functional tasks may benefit from the improvement of power at values other than “ peak ” values , for example , tasks that require a greater velocity component or a greater force component . This study compared the effect of high-speed RT on muscle performance ( peak power [ PP ] and its components [ PP force and PP velocity ] and overall peak velocity [ VEL ] ) across a broad range of external resistances . Thirty-eight older men and women were r and omized  to high-speed power training at 40 % of the 1-repetition maximum ( 1RM ) ( n = 13 [ 74.1 ± 6.4 years ] ) ; traditional RT at 80 % 1RM ( n = 13 [ 70.1 ± 7.0 years ] ) ; or control ( n = 12 [ 72.8 ± 4.1 years ] ) . Measures of muscle performance were obtained at baseline and after the 12-week training intervention . Muscle power and 1RM strength improved similarly with both high-speed and traditional slow-speed RT . However , speed-related muscle performance characteristics , PP velocity and overall VEL , were most positively impacted by high-speed power training , especially at lower external resistances . Because gains in speed-related measures with high-speed training compared to traditional RT do not come at the expense of other muscle performance outcomes , we recommend using an RT protocol in older adults that emphasizes high-speed movements at low external resistances We examined whether high-speed power training ( HSPT )  improved muscle performance and braking speed using a driving simulator . 72 older adults ( 22 m , 50 f ; age = 70.6 ± 7.3 yrs ) were r and omized to HSPT at 40 % one-repetition maximum ( 1RM ) ( HSPT : n = 25 ; 3 sets of 12–14 repetitions ) , slow-speed strength training at 80%1RM ( SSST : n = 25 ; 3 sets of 8–10 repetitions ) , or control ( CON : n = 22 ; stretching ) 3 times/week for 12 weeks . Leg press and knee extension peak power , peak power velocity , peak power force/torque , and braking speed were obtained at baseline and 12 weeks . HSPT  increased peak power and peak power velocity across a range of external resistances ( 40–90 % 1RM ; P < 0.05 ) and improved braking speed ( P < 0.05 ) . Work was similar between groups , but perceived exertion was lower in HSPT ( P < 0.05 ) . Thus , the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST Background Slow gait is common in dementia , but it remains unknown whether the slowing happens many years prior to dementia onset . We therefore examined the relationship between slow baseline gait speed ( GS ) , change in GS , and the hazard of incident dementia  in a community dwelling of elderly people . Methods A total of 3,663 participants dementia-free at baseline ( mean age , 73.5 years ) were followed up for 9 years from a prospect i ve cohort ( Three-City study , France ) for incident dementia ( all-cause , Alzheimer 's disease , vascular dementia , and other causes ) .  GS  over 6 m was assessed 4 times over the follow-up using two photoelectric cells . We used a multistate model to estimate the hazard ratio ( HR ) of dementia for baseline GS and tested a washout period of 4 to 7 years . The role of GS change between 65 and 85 years was examined using linear mixed models and joint models for survival and longitudinal data . Results A total of 296 participants developed dementia  during the follow-up . In age/sex-adjusted models , 1-SD ( 0.204 m/s ) lower GS was associated with an increased hazard of dementia ( HR = 1.59 , 95 % confidence interval [ CI ] = 1.39 , 1.81 , p < .001 ) , with associations evident when gait assessment s were taken from 4 years ( HR = 1.46 ; CI = 1.26 , 1.68 ) and 7 years ( HR=1.30 ; CI = 1.00 , 1.70 ) prior to dementia onset . Independently of baseline GS , those with a steeper decline had a higher hazard of dementia ( HR per 1 SD [ 0.007 m/s/year ] decrease = 3.39 [ 1.37 - 8.43 ] , p = .009 ) . Conclusions Gait is slower up to 7 years prior to clinical onset of dementia . Decline in GS is also more accelerated , suggesting strong links between cognitive and motor function in older adults Context : Findings of studies of testosterone ’s effects on muscle strength and physical function  in older men have been inconsistent ; its effects on muscle power and fatigability have not been studied . Objective : To determine the effects of testosterone administration for 3 years in older men on  muscle strength , power , fatigability , and physical function . Design , Setting , and Participants : This was a double-blind , placebo-controlled , r and omized trial of healthy men ≥60 years old with total testosterone levels of 100 to 400 ng/dL or free testosterone levels < 50 pg/mL. Interventions : R and om assignment to 7.5 g of 1 % testosterone or placebo gel daily for 3 years . Outcome Measures : Loaded and unloaded stair-climbing power , muscle strength , power , and fatigability in leg press and chest press exercises , and lean mass at baseline , 6 , 18 , and 36 months . Results : The groups were similar at baseline . Testosterone administration for 3 years was associated with significantly greater performance in unloaded and loaded stair-climbing power  than placebo ( mean estimated between-group difference , 10.7 W [ 95 % confidence interval ( CI ) , −4.0 to 25.5 ] , P = 0.026 ; and 22.4 W [ 95 % CI , 4.6 to 40.3 ] , P = 0.027 ) , respectively . Changes in chest-press strength ( estimated mean difference , 16.3 N ; 95 % CI , 5.5 to 27.1 ; P < 0.001 ) and power ( mean difference 22.5 W ; 95 % CI , 7.5 to 37.5 ; P < 0.001 ) , and leg-press power were significantly greater in men r and omized to testosterone than in those r and omized to  placebo . Lean body mass significantly increased more in the testosterone group . Conclusion : Compared with placebo , testosterone replacement in older men for 3 years was associated with modest but significantly greater improvements in stair-climbing power , muscle mass , and power . Clinical meaningfulness of these treatment effects and their impact on disability in older adults with functional limitations remains to be studied BACKGROUND Muscle power ( force x velocity ) recedes at a faster rate than strength with age and may also be a stronger predictor of fall risk and functional decline . The optimal training paradigm for improving muscle power in older adults is not known , although some literature suggests high velocity , low load training is optimal in young adults . METHODS One hundred twelve healthy older adults ( 69 + /- 6 years ) were r and omly assigned to either explosive resistance training at 20 % ( G20 ) , 50 % ( G50 ) , or 80 % ( G80 ) one repetition maximum ( 1RM ) for 8 - 12 weeks or to a nontraining control group ( CON ) . Participants trained twice per week ( five exercises ; three sets of eight rapidly concentric and slow eccentric repetitions ) using pneumatic resistance machines . Repeated- measures analysis of variance and covariance ( ANOVA and ANCOVA ) were used to determine the effects of training . RESULTS Average peak power increased significantly and similarly in G80 ( 14 + /- 8 % ) , G50 ( 15 + /- 9 % ) , and G20 ( 14 + /- 6 % ) compared to CON ( 3 + /- 6 % ) ( p < .0001 ) . By contrast , a positive dose-response relationship with training intensity was observed for relative changes in average strength ( r = .40 , p = .0009 ) and endurance ( r = .43 , p = .0005 ) . Average strength increased in G80 ( 20 + /- 7 % ) , G50 ( 16 + /- 7 % ) , and G20 ( 13 + /- 7 % ) compared to CON ( 4 + /- 4 % ) ( p < .0001 ) . Average muscle endurance increased in G80 ( 185 + /- 126 % , p < .0001 ) , G50 ( 103 + /- 75 % , p = .0004 ) , and G20 ( 82 + /- 57 % , p = .0078 ) compared to CON ( 28 + /- 29 % ) . CONCLUSION Peak muscle power may be improved similarly using light , moderate , or heavy resistances , whereas there is a dose-response relationship between training intensity and muscle strength and endurance changes . Therefore , using heavy loads during explosive resistance training may be the most effective strategy to achieve simultaneous improvements in muscle strength , power , and endurance in older adults Improving muscle strength and power may mitigate the effects of sarcopenia , but it is unknown if this improves an older adult ’s 
    Output:
    