***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 The role of weight training in the primary prevention of  type 2 diabetes mellitus ( T2DM ) is largely unknown . METHODS To examine the association of weight training with  risk of T2DM in US men and to assess the influence of combining weight training and aerobic exercise , we performed a prospect i ve cohort study of 32 002 men from the Health Professionals Follow-up Study observed from 1990 to 2008 . Weekly time spent on weight training and aerobic exercise ( including brisk walking , jogging , running , bicycling , swimming , tennis , squash , and calisthenics/rowing ) was obtained from question naires at baseline and biennially during follow-up . RESULTS During 508 332 person-years of follow-up ( 18 years ) , we documented 2278 new cases of T2DM . In multivariable-adjusted models , we observed a dose-response relationship between an increasing amount of time spent on weight training or aerobic exercise  and lower risk of T2DM ( P < .001 for trend ) . Engaging in weight training or aerobic exercise for at least 150 minutes per week was independently associated with a lower risk of T2DM of 34 % ( 95 % CI , 7%-54 % ) and 52 % ( 95 % CI , 45%-58 % ) , respectively . Men who engaged in aerobic exercise and weight training for at least 150 minutes per week had the greatest reduction in T2DM risk ( 59 % ; 95 % CI , 39%-73 % ) . CONCLUSIONS Weight training was associated with a significantly lower risk of T2DM , independent of aerobic exercise . Combined weight training and aerobic exercise conferred a greater benefit We examined the independent and combined associations of physical activity and obesity with  incident type 2 diabetes in men and women . The InterAct case – cohort study consists of 12,403 incident type 2 diabetes cases and a r and omly selected subcohort of 16,154 individuals , drawn from a total cohort of 340,234 participants with 3.99 million person-years of follow-up .  Physical activity  was assessed by a four-category index . Obesity was measured by BMI and waist circumference ( WC ) . Associations between  physical activity , obesity and case-ascertained incident type 2 diabetes were analysed by Cox regression after adjusting for educational level , smoking status , alcohol consumption and energy intake . In combined analyses , individuals were stratified according to physical activity level , BMI and WC . A one-category difference in physical activity ( equivalent to approximately 460 and 365 kJ/day in men and women , respectively ) was independently associated with a 13 % ( HR 0.87 , 95 % CI 0.80 , 0.94 ) and 7 % ( HR 0.93 , 95 % CI 0.89 , 0.98 ) relative reduction in the risk of type 2 diabetes in men and women , respectively . Lower levels of physical activity  were associated with an increased risk of diabetes across all strata of BMI . Comparing inactive with active individuals , the HRs were 1.44 ( 95 % CI 1.11 , 1.87 ) and 1.38 ( 95 % CI 1.17 , 1.62 ) in abdominally lean and obese inactive men , respectively , and 1.57 ( 95 % CI 1.19 , 2.07 ) and 1.19 ( 95 % CI 1.01 , 1.39 ) in abdominally lean and obese inactive women , respectively .  Physical activity is associated with a reduction in the risk of developing type 2 diabetes across BMI categories in men and women , as well as in abdominally lean and obese men and women Purpose To assess the dose-response relationships between cause-specific mortality and exercise energy expenditure in a prospect i ve epidemiological cohort of walkers . Methods The sample consisted of the 8,436 male and 33,586 female participants of the National Walkers ' Health Study .  Walking energy expenditure was calculated in metabolic equivalents ( METs , 1 MET = 3.5 ml O2/kg/min ) , which were used to divide the cohort into four exercise categories : category 1 ( ≤1.07 MET-hours/d ) , category 2 ( 1.07 to 1.8 MET-hours/d ) , category 3 ( 1.8 to 3.6 MET-hours/d ) , and category 4 ( ≥3.6 MET-hours/d ) . Competing risk regression analyses were use to calculate the risk of mortality for categories 2 , 3 and 4 relative to category 1 . Results 22.9 % of the subjects were in category 1 , 16.1 % in category 2 , 33.3 % in category 3 , and 27.7 % in category 4 . There were 2,448 deaths during the 9.6 average years of follow-up . Total mortality was 11.2 % lower in category 2 ( P = 0.04 ) , 32.4 % lower in category 3 ( P<10−12 ) and 32.9 % lower in category 4 ( P = 10−11 ) than in category 1 . For underlying causes of death , the respective risk reductions for categories 2 , 3 and 4 were 23.6 % ( P = 0.008 ) , 35.2 % ( P<10−5 ) , and 34.9 % ( P = 0.0001 ) for cardiovascular disease mortality ; 27.8 % ( P = 0.18 ) , 20.6 % ( P = 0.07 ) , and 31.4 % ( P = 0.009 ) for ischemic heart disease mortality ; and 39.4 % ( P = 0.18 ) , 63.8 % ( P = 0.005 ) , and 90.6 % ( P = 0.002 ) for diabetes mortality when compared to category 1 . For all related mortality ( i.e. , underlying and contributing causes of death combined ) , the respective risk reductions for categories 2 , 3 and 4 were 18.7 % ( P = 0.22 ) , 42.5 % ( P = 0.001 ) , and 57.5 % ( P = 0.0001 ) for heart failure ; 9.4 % ( P = 0.56 ) , 44.3 % ( P = 0.0004 ) , and 33.5 % ( P = 0.02 ) for hypertensive diseases ; 11.5 % ( P = 0.38 ) , 41.0 % ( P<10−4 ) , and 35.5 % ( P = 0.001 ) for dysrhythmias : and 23.2 % ( P = 0.13 ) , 45.8 % ( P = 0.0002 ) , and 41.1 % ( P = 0.005 ) for cerebrovascular diseases when compared to category 1 . Conclusions There are substantial health benefits to exceeding the current exercise guidelines AIMS To investigate association between leisure-time physical activity at weekends and the risk of developing Type 2 diabetes mellitus ( DM ) . METHODS Prospect i ve examination of 6,013 Japanese men aged 35 - 60 years who were free of DM , impaired fasting glycaemia , or hypertension at study entry . Type 2 DM was defined by a fasting plasma glucose level > or = 7.0 mmol/l or a 2-h post-load plasma glucose level > or = 11.1 mmol/l . Data on physical activity obtained from question naires consisted of overall leisure-time physical activity weekly and leisure-time physical activity at weekends . RESULTS During the 59,966 person-years follow-up , 444 cases developed Type 2 DM .  Regular physical exercise at least once a week was associated with a reduced risk of Type 2 DM . After adjustments for age , body mass index , daily alcohol consumption , smoking habits , blood pressure levels and a parental history of Type 2 DM , men who engaged in regular physical exercise at least once a week had a relative risk of Type 2 DM of 0.75 ( 95 % CI , 0.61 - 0.93 ) compared with men engaging in exercise less often . Even vigorous activity only once a week at weekends was associated with a reduced risk of Type 2 DM . Men who engaged in vigorous activity at least once a week at weekends had a multiple-adjusted relative risk of Type 2 DM of 0.55 ( 95 % CI , 0.35 - 0.88 ) compared with sedentary men . CONCLUSIONS Regular physical exercise at least once a week and vigorous activity even only once a week at weekends are associated with a decreased risk of Type 2 DM An association between physical inactivity and obesity risk has been established . However , the relationship between sports activity and the risk of diabetes among Chinese population s is still unclear . We prospect ively investigated the association between sports activity and incidence of type 2 diabetes in a Chinese population .  Habitual physical activity in the presumed last year was obtained from a question naire developed by Baecke and colleagues . During a median 9.02-year follow-up period among the 1936 participants with complete question naire data , 312 participants developed diabetes . After adjusting for age , gender and body mass index , the relative risk ( RR ) of diabetes according to quartiles of sports activity were 0.86 , 0.71 and 0.72 ( 95 % Confidence Interval [ CI ] , 0.52 - 0.99 , P for trend , 0.048 ) . Participants with the highest quartiles of sports activity had a significantly lower risk than the participants with the lowest quartiles among the obese group ( multivariate RR , 0.61 , 95 % CI , 0.41 - 0.92 , P for trend=0.018 ) . Furthermore , the RRs of diabetes were 2.24 ( 95 % CI , 1.58 - 3.19 ) for participants who were obese and sedentary , compared with those who were of a healthy weight and participated actively in sports . The findings suggest a significant inverse association between sports activity  and incidence of type 2 diabetes in middle to older-aged Chinese individuals BACKGROUND Leisure-time physical activity ( LPA ) has been associated with a reduced risk of type 2 diabetes . However , the potential effect of other types of physical activity on type 2 diabetes is still uncertain . The aim of this study was to examine the effect of occupational , commuting , daily living , and LPA on the incidence of  type 2 diabetes in a cohort of middle-aged women . METHODS We prospect ively followed 70,658 women who had no prior history of diabetes at study recruitment for 4.6 years . Participants completed in-person interviews at baseline that collected information on diabetes risk factors including physical activity habits .  Anthropometric measurements  were taken by trained interviewers . Multivariate-adjusted hazard ratios were estimated by levels of occupational , commuting , daily living , and LPA . RESULTS We documented 1973 incident cases of diabetes during 326,625 person-years of follow-up .  LPA  and  daily living physical activity ( DPA  ) were associated with a moderately reduced risk of type 2 diabetes . The relative risk for type 2 diabetes associated with LPA and DPA categories were 1.00 , 0.89 , 1.05 , and 0.83 , ( P trend = 0.12 ) and 1.00 , 0.98 , 0.95 , and 0.88 , ( P trend = 0.06 ) respectively . LPA was associated with lower risk of type 2 diabetes in employed participants ( P trend = 0.09 ) while DPA was mainly associated with a reduction in risk in non-employed participants ( P trend < 0.01 ) . While occupational physical activity was not associated with type 2 diabetes risk in this population , commuting to work was associated with a reduction in risk . A combination of DPA and LPA was associated with a reduced risk of type 2 diabetes . CONCLUSIONS This study suggests that physical activity , either from leisure-time exercise or daily activity reduces the risk of type 2 diabetes in women , supporting the current health promotion efforts encouraging both exercise and non-exercise activity levels BACKGROUND To evaluate the hypothesis that physical activity independently predicts type 2 diabetes  risk in postmenopausal African-American , Hispanic , Asian , and Caucasian women . METHODS We prospect ively evaluated the relationship between incident type 2 diabetes , walking , and total physical activity  at baseline in the Women 's Health Initiative Observational Study . Baseline data were collected between September 1994 and December 1998 ; incident diabetes was identified through August 2002 . Hazard ratios for self-reported diabetes adjusted for body mass index ( BMI ) and other variables were evaluated across categories of physical activity in Caucasian , African-American , Hispanic , and Asian/Pacific Isl and er women . RESULTS Incident diabetes was reported by 2.2 % of Caucasian , 6.2 % of African-American , 4.5 % of Hispanic , 3 % of Asian , and 5.7 % of American Indian women ( p < 0.0001 across ethnic groups ) during 458,018 woman-years of follow-up . Among Caucasian women ,  walking  ( multivariate-adjusted hazard ratios  
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Results for the MMET h/week dose – response curve were similar for moderate intensity PA  , but benefits were greater for higher intensity PA  and smaller for lower intensity activity .
Conclusions /interpretationHigher levels of LTPA were associated with substantially lower incidence of type 2 diabetes in the general population .
The relationship between LTPA and type 2 diabetes was curvilinear ; the greatest relative benefits are achieved at low levels of activity , but additional benefits can be realised at exposures considerably higher than those prescribed by public health recommendations