***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: Background Age‐related endothelial dysfunction and vascular stiffening are associated with increased cardiovascular ( CV ) risk . Many groups have encouraged goals of ≥10 000 steps/day or ≥30 min/day of moderate intensity physical activity ( MPA ) to reduce age‐related CV risk . The impact of MPA on the vasculature of older adults remains unclear . Methods and Results We r and omized 114 sedentary older adults ages ≥50 to 12 weeks of either no intervention ( group 1 ) , a pedometer‐only intervention ( group 2 ) , or a pedometer with an interactive website employing strategies to increase the adoption of habitual physical activity ( PA , group 3 ) . Endothelial function by brachial flow‐mediated dilation ( FMD% ) , vascular stiffness by tonometry , step‐count by pedometer , and PA intensity/distribution by accelerometer were measured . Step‐count increased in groups 2 ( 5136±1554 to 9596±3907 , P<0.001 ) and 3 ( 5474±1512 to 8167±3111 , P<0.001 ) but not in group 1 ( 4931±1667 to 5410±2410 ) . Both groups 2 and 3 increased MPA ≥30 min/day . Only group 3 increased MPA in continuous bouts of ≥10 minutes ( P<0.001 ) and improved FMD% ( P=0.001 ) . Neither achievement of ≥10 000 steps/day nor ≥30 min/day of MPA result ed in improved FMD% . However , achieving ≥20 min/day in MPA bouts result ed in improved FMD% . No changes in vascular stiffness were observed . Conclusions MPA reverses age‐related endothelial dysfunction , but may require MPA to be performed in bouts of ≥10 minutes duration for ≥20 min/day to be effective . Commonly encouraged PA goals do not guarantee improved endothelial function and may not be as effective in reducing CV risk . Clinical Trial Registration URL : Clinical trials.gov . Unique identifier : NCT‐01212978 Background Self – reported physical activity has been inversely associated with mortality but the effect of objective ly measured step activity on mortality has never been evaluated . The objective is to determine the prospect i ve association of daily step activity on mortality  among free-living adults . Methods and Findings Cohort study of free-living adults residing in Tasmania , Australia between 2000 and 2005 who participated in one of three cohort studies ( n = 2 576 total participants ) .  Daily step activity by pedometer at baseline at a mean of 58.8 years of age , and for a subset , repeated monitoring was available 3.7 ( SD 1.3 ) years later ( n = 1 679 ) . All-cause mortality ( n = 219 deaths ) was ascertained by record-linkage to the Australian National Death Index ; 90 % of participants were followed-up over ten years , until June 2011 . Higher daily step count at baseline was linearly associated with lower all-cause mortality ( adjusted hazard ratio AHR , 0.94 ; 95 % CI , 0.90 to 0.98 per 1 000 steps ; P = 0.004 ) . Risk was altered little by removing deaths occurring in the first two years . Increasing baseline daily steps from sedentary to 10 000 steps a day was associated with a 46 % ( 95 % CI , 18 % to 65 % ; P = 0.004 ) lower risk of mortality in the decade of follow-up . In addition , those who increased their daily steps over the monitoring period had a substantial reduction in mortality risk , after adjusting for baseline daily step count ( AHR , 0.39 ; 95 % CI , 0.22 to 0.72 ; P = 0.002 ) , or other factors ( AHR , 0.38 ; 95 % CI , 0.21–0.70 ; P = 0.002 ) . Conclusions Higher daily step count was linearly associated with subsequent long term mortality among free living adults . These data are the first to quantify mortality reductions using an objective measure of physical activity in a free living population . They strongly underscore the importance of physical inactivity as a major public health problem Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Being overweight is associated with vascular abnormalities , which are important in the development of atherosclerosis . However , little is known about dietary and lifestyle determinants of vascular function in overweight children . In adults , dietary protein and milk intake are associated with reduced blood pressure and reduced risk of metabolic syndrome . This study examined the associations between dietary protein , milk intake , physical activity , and adiposity on arterial stiffness in overweight children . In a cross-sectional study , overweight children with habitual milk intakes ≤ 250 mL/d were examined by DXA scans , pedometer counts , anthropometry , and metabolic variables . Dietary intake was registered for 4 d. The outcomes were arterial stiffness measured by pulse wave velocity ( PWV ) ( n = 182 ) and augmentation index ( Aix ) ( n = 183 ) . The PWV ( mean ± SD ) was 4.78 ± 0.72 m/s and the Aix was -0.77 ± 9.44 % . In multivariate models , the and roid fat : gynoid fat and and roid fat : body fat ratios were positively associated with PWV ( β = 1.49 and β = 10.3 , both P < 0.05 ) and Aix ( β = 28.3 , P < 0.01 and β = 153 , P < 0.05 ) , whereas the gynoid fat : body fat ratio was negatively associated with the Aix ( β = -134 ; P < 0.001 ) . Protein intake ( percentage energy ) was positively associated with PWV ( β = 0.05 ; P < 0.01 ) . Milk intake ( L/d ) tended to be negatively associated with PWV ( β = -0.64 ; P = 0.05 ) . Pedometer counts were negatively associated with the Aix ; however , the association became nonsignificant after controlling for HOMA , which was positively associated with the Aix ( β = 0.95 ; P < 0.01 ) . In conclusion , central adiposity and protein intake are associated with increased arterial stiffness measured as PWV in overweight children independent of blood pressure and heart rate . The effect of protein intake may be caused by meat , because the milk intake was low Background New technologies could facilitate changes in lifestyle and improve public health . However , no large r and omized , controlled studies providing scientific evidence of the benefits of their use have been made . The aims of this study are to develop and vali date a smartphone application , and to evaluate the effect of adding this tool to a st and ardized intervention design ed to improve adherence to the Mediterranean diet and to physical activity . An evaluation is also made of the effect of modifying habits upon vascular structure and function , and therefore on arterial aging . Methods / Design A r and omized , double-blind , multicenter , parallel group clinical trial will be carried out . A total of 1215 subjects under 70 years of age from the EVIDENT trial will be included . Counseling common to both groups ( control and intervention ) will be provided on adaptation to the Mediterranean diet and on physical activity . The intervention group moreover will receive training on the use of a smartphone application design ed to promote a healthy diet and increased physical activity , and will use the application for three months . The main study endpoints will be the changes in physical activity , assessed by accelerometer and the 7-day Physical Activity Recall ( PAR ) interview , and adaptation to the Mediterranean diet , as evaluated by an adherence question naire and a food frequency question naire ( FFQ ) . Evaluation also will be made of vascular structure and function based on central arterial pressure , the radial augmentation index , pulse velocity , the cardio-ankle vascular index , and carotid intima-media thickness . Discussion Confirmation that the new technologies are useful for promoting healthier lifestyles and that their effects are beneficial in terms of arterial aging will have important clinical implication s , and may contribute to generalize their application in favor of improved population health . Trial registration Clinical Trials.gov Identifier : CONTEXT Persuasive evidence has demonstrated that increased physical activity is associated with substantial reduction in risk of coronary heart disease . However , the role of physical activity in the prevention of stroke is less well established . OBJECTIVE To examine the association between physical activity and risk of  total stroke and stroke subtypes in women . DESIGN AND SETTING The Nurses ' Health Study , a prospect i ve cohort study of subjects residing in 11 US states . SUBJECTS A total of 72,488 female nurses aged 40 to 65 years who did not have diagnosed cardiovascular disease or cancer at baseline in 1986 and who completed detailed physical activity question naires in 1986 , 1988 , and 1992 . MAIN OUTCOME MEASURE Incident stroke occurring between baseline and June 1 , 1994 , compared among quintiles of physical activity level as measured by metabolic equivalent tasks ( METs ) in hours per week . RESULTS During 8 years ( 560,087 person-years ) of follow-up , we documented 407 incident cases of stroke ( 258 ischemic strokes , 67 subarachnoid hemorrhages , 42 intracerebral hemorrhages , and 40 strokes of unknown type ) . In multivariate analyses controlling for age , body mass index , history of hypertension , and other covariates , increasing physical activity was strongly inversely associated with risk of total stroke . Relative risks ( RRs ) in the lowest to highest MET quintiles were 1 . 00 , 0.98 , 0.82 , 0.74 , and 0.66 ( P for trend=.005 ) . The inverse gradient was seen primarily for ischemic stroke ( RRs across increasing MET quintiles , 1.00 , 0.87 , 0.83 , 0.76 , and 0.52 ; P for trend=.003 ) .  Physical activity  was not significantly associated with subarachnoid hemorrhage or intracerebral hemorrhage . After multivariate adjustment , walking was associated with reduced risk of total stroke ( RRs across increasing walking MET quintiles , 1.00 , 0 . 76 , 0.78 , 0.70 , and 0.66 ; P for trend=.01 ) and ischemic stroke ( RRs across increasing walking MET quintiles , 1.00 , 0.77 , 0.75 , 0.69 , and 0.60 ; P for trend=.02 ) . Brisk or striding walking pace was associated with lower risk of total and ischemic stroke compared with average or casual pace . CONCLUSION These data indicate that physical activity , including moderate-intensity exercise such as walking , is associated with substantial reduction in risk of total and ischemic stroke in a dose-response manner . JAMA . 2000 Background : Physical activity ( PA ) is inversely associated with obesity but the effect has been difficult to quantify using question naires . In particular , the shape of the association has not yet been well described . Pedometers provide an opportunity to better characterize the association . Methods : Residents of households over the age of 25 years in r and omly selected census districts in Tasmania were eligible to participate in the AusDiab cross-sectional survey conducted in 1999–2000 . 1848 completed the AusDiab survey and 1126 of these ( 609 women and 517 men ) wore a pedometer for 2-weekdays . Question naire data on  recent PA , TV time  and other factors were obtained . The outcomes were waist circumference ( in cm ) and body mass index ( BMI ) ( kg/m2 ) . Results : Increasing daily steps were associated with a decline in the obesity measures . The logarithmic nature of the associations was indicated by a sharper decline for those with lower daily steps . For example , an additional 2000 steps for those taking only 2000 steps per day was associated with a reduction of 2.8 ( 95 % confidence interval ( CI ) : 2.1,4.4 ) cm in waist circumference among men ( for women ; 2.2 ( 95 % CI : 0.6 , 3.9 cm ) ) with a baseline of only 2000 , steps compared to a 0.7 ( 95 % CI 0.3 , 1.1 ) cm reduction ( for women ; 0.6 ( 95 % CI : 0.2 , 1.0 ) ) for those already walking 10 000 steps daily . In the multivariable analysis , clearer associations were detected for  PA and these obesity measures using daily step number rather than PA time by question naire . Interpretation : Pedometer measures of activity indicate that the inverse association between recent  PA  and obesity is logarithmic in form with the greatest impact for a given arithmetic step number increase seen at lower levels of baseline activity . The findings from this study need to be examined in prospect i ve setting The central arteries stiffen with age , causing hemodynamic alterations that have been associated with cardiovascular events . Changes in body fat with age may be 
    Output:
    
This systematic review and meta- analysis demonstrates a clinical ly meaningful association between objective ly monitored steps per day and PWv , an accepted indicator of arterial stiffness and an early sub clinical risk factor for cardiovascular disease .