A prospective study of pregravid physical activity and sedentary behaviors in relation to the risk for gestational diabetes mellitus. Physical activity, sedentary behaviors and risk of gestational diabetes mellitus: a population-based cross-sectional study in Tianjin, China. Sedentary behaviors and abnormal glucose tolerance among pregnant Latina women. Impact of objectively measured sedentary behaviour on changes in insulin resistance and secretion over 3 years in the RISC study: interaction with weight gain. A Randomised Controlled Trial to Reduce Sedentary Time in Young Adults at Risk of Type 2 Diabetes Mellitus: Project STAND (Sedentary Time ANd Diabetes) The Relationship of Objectively Measured Physical Activity and Sedentary Behaviour with Gestational Weight Gain and Birth Weight Physical activity and sedentary behaviors associated with risk of progression from gestational diabetes mellitus to type 2 diabetes mellitus: a prospective cohort study. Design of FitFor2 study: the effects of an exercise program on insulin sensitivity and plasma glucose levels in pregnant women at high risk for gestational diabetes Association between Physical Activity in Obese Pregnant Women and Pregnancy Outcomes: The UPBEAT Pilot Study Perceived Exertion in Physical Activity and Risk of Gestational Diabetes Mellitus Physical activity during pregnancy and offspring cardiovascular risk factors: findings from a prospective cohort study The association of daily physical activity and birth outcome: a population-based cohort study Patterns of Sedentary Behavior and Mortality in U.S. Middle-Aged and Older Adults Women's behaviour, beliefs and information sources about physical exercise in pregnancy. Physical and psychological changes with vigorous exercise in sedentary primigravidae. Sedentary behavior during postnatal life is determined by the prenatal environment and exacerbated by postnatal hypercaloric nutrition. Sedentary behavior and mortality in older women: the Women's Health Initiative.
BACKGROUND Although gestational diabetes mellitus ( GDM ) has been associated with substantial adverse health outcomes for both mothers and offspring , few modifiable risk factors for GDM have been identified . METHODS We conducted a prospect i ve cohort study among women in the Nurses ' Health Study II to assess whether the amount , type , and intensity of pregravid physical activity and sedentary behaviors are associated with GDM risk . The analysis included 21,765 women who reported at least 1 singleton pregnancy between 1990 and 1998 .  Physical activity and sedentary behaviors  were assessed through vali date d question naire . RESULTS We documented 1428 incident GDM cases . After controlling for body mass index , dietary factors , and other covariates , there was a significant inverse association between vigorous activity and the risk of GDM . The multivariate relative risk ( RR ) comparing the highest with the lowest quintile of vigorous activity was 0.77 ( 95 % confidence interval [ CI ] , 0.69 - 0.94 ) ( P = .002 for trend ) . Among women who did not perform vigorous activity , brisk walking pace was associated with significantly lower GDM risk ( RR , 0.66 ; 95 % CI , 0.46 - 0.95 ) compared with an easy pace . Women who spent 20 h/wk or more watching television but did not perform vigorous activity had a significantly higher GDM risk than women who spent less than 2 h/wk watching television and were physically active ( multivariate RR , 2.30 ; 95 % CI , 1.06 - 4.97 ) . CONCLUSION Our prospect i ve study provides strong evidence that regular physical activity before pregnancy is associated with lower GDM risk OBJECTIVE Physical activity in a nonpregnant state or before pregnancy reduces the risk of  type 2 diabetes  and is also associated with reduced risk of gestational diabetes mellitus ( GDM ) . However , it is uncertain whether physical activity during pregnancy reduces the risk of GDM . DESIGN AND METHODS Using an established universal screening system in Tianjin , China , we prospect ively recruited 11 450 pregnant women within the 12th gestational week from 2010 to 2012 . These women underwent a 50-g 1-h glucose challenge test ( GCT ) at 24 - 28 weeks of gestation and a 75-g 2-h oral glucose tolerance test if GCT glucose ≥7.8mmol/L. GDM was defined according to the International Association of Diabetes and Pregnancy Study Group 's criteria .  Self-reported physical activity  in the last month was collected at GCT time using a vali date d question naire . RESULTS GDM developed in 7.3 % ( n=840 ) of the women . Women with GDM were less likely to be engaged in moderate-to-high physical activity during pregnancy than those without ( 79.8 % vs 81.6 % , P=0.191 ) .  Moderate-to-high physical  activity during pregnancy was associated with decreased risk of GDM ( multivariable odds ratio ( OR ) : 0.81 , 95 % confidence interval ( CI ) : 0.67 - 0.97 ) . Sitting at home for 2 - 4h per day and > 4h per day were associated with significantly increased risk of GDM ( multivariable OR of sitting time for 2 - 4h vs < 2h : 1.59 , 95 % CI : 1.18 - 2.15 ; OR of sitting time for > 4h vs < 2h : 1.73 , 95 % CI : 1.22 - 2.43 ) . CONCLUSIONS Increased physical activity during pregnancy was associated with reduced GDM risk , whereas sedentary lifestyle was associated with increased GDM risk among Chinese pregnant women UNLABELLED Studies conducted among nonpregnant population s have observed an association between sedentary behavior and glucose intolerance . Few studies have investigated this association during pregnancy , particularly among Latina women , a population with higher rates of sedentary behavior and abnormal glucose tolerance ( AGT ) as compared with non-Latina white women . OBJECTIVE The purpose of this study was to estimate the association between sedentary behavior and AGT . RESEARCH DESIGN AND METHODS We used data from the Latina gestational diabetes mellitus study , a prospect i ve cohort of 1231 Latina prenatal care patients in western Massachusetts .  Sedentary behavior  was assessed by bilingual interviewers using a modified version of the  Kaiser Physical Activity Survey  in prepregnancy , early pregnancy , and midpregnancy and defined as hours spent TV watching , frequency of sitting at work , and participation in sports or exercise activity as well as a derived composite of total sedentary activity . AGT was measured at 24 - 28 wk of gestation and abstract ed from medical records after delivery . Multivariate logistic regression was used to calculate odds ratios and 95 % confidence intervals . RESULTS A total of 12 % ( n = 119 ) of participants were classified as having AGT . After adjusting for AGT risk factors , sedentary behaviors in prepregnancy or in early pregnancy were not associated with AGT . However , in midpregnancy , low levels of participation in sports or exercise ( odds ratio = 2.01 , 95 % CI = 1.01 - 4.02 ) and increasing total sedentary activity ( Ptrend = 0.003 ) were associated with increased risk for AGT . CONCLUSIONS Findings suggest an association between sedentary activity in midpregnancy and risk of AGT in this understudied population AIMS The importance of reducing sedentary time is increasingly being recognized in the prevention of diabetes and cardiovascular disease . Despite this , the prospect i ve association between sedentary time and physical activity with insulin sensitivity and cardiometabolic risk factors has been little studied . METHODS In an analysis of data from the European RISC study , sedentary time and time spent in activity of moderate or vigorous intensity were assessed by accelerometry at baseline in 313 men and 414 women , aged 30 - 60 years , with insulin sensitivity as measured by euglycaemic-hyperinsulinaemic clamp . Three years later , cardiometabolic risk factors ( anthropometry , glucose , insulin , lipids ) were available for 549 participants . RESULTS In cross-sectional analyses using baseline data , after adjusting for age , gender , recruitment centre and time spent in activity of moderate or vigorous intensity , significant unfavourable associations were observed between higher sedentary time with body weight , HDL cholesterol , triglycerides , clamp-measured insulin sensitivity and insulin secretion ( all P(trend)<0.002 ) .  Sedentary time  remained significantly associated with insulin secretion after adjusting for insulin sensitivity ( P(trend)=0.02 ) . In longitudinal analyses , higher baseline sedentary time  was associated with 3-year increases in fasting glucose , fasting insulin and the HOMA insulin-resistance index score for the 50 % of the study population who increased their BMI by at least 0.3 kg/m(2 ) ( all P(trend)<0.01 ) ; these relationships remained significant after adjusting for time spent in activity of moderate or vigorous intensity . The 3-year increase in insulin secretion was lower in those spending more time doing activity of moderate or vigorous intensity ( P(trend)=0.03 ) . CONCLUSION These prospect i ve data suggest that less sedentary behaviour may partly counteract some of the negative effects of increasing body weight on glucose-insulin homoeostasis Aims Type 2 diabetes mellitus ( T2DM ) , a serious and prevalent chronic disease , is traditionally associated with older age . However , due to the rising rates of obesity and sedentary lifestyles , it is increasingly being diagnosed in the younger population . Sedentary ( sitting ) behaviour has been shown to be associated with greater risk of cardio-metabolic health outcomes , including T2DM . Little is known about effective interventions to reduce sedentary behaviour in younger adults at risk of T2DM . We aim ed to investigate , through a r and omised controlled trial ( RCT ) design , whether a group-based structured education workshop focused on sitting reduction , with self-monitoring , reduced sitting time . Methods Adults aged 18–40 years who were either overweight ( with an additional risk factor for T2DM ) or obese were recruited for the Sedentary Time ANd Diabetes ( ST AND ) RCT . The intervention programme comprised of a 3-hour group-based structured education workshop , use of a self-monitoring tool , and follow-up motivational phone call . Data were collected at three time points : baseline , 3 and 12 months after baseline . The primary outcome measure was accelerometer-assessed sedentary behaviour after 12 months . Secondary outcomes included other objective ( activPAL ) and self-reported measures of sedentary behaviour and physical activity , and biochemical , anthropometric , and psycho-social variables . Results 187 individuals ( 69 % female ; mean age 33 years ; mean BMI 35 kg/m2 ) were r and omised to intervention and control groups . 12 month data , when analysed using intention-to-treat analysis ( ITT ) and per- protocol analyses , showed no significant difference in the primary outcome variable , nor in the majority of the secondary outcome measures . Conclusions A structured education intervention design ed to reduce sitting in young adults at risk of T2DM was not successful in changing behaviour at 12 months . Lack of change may be due to the brief nature of such an intervention and lack of focus on environmental change . Moreover , some participants reported a focus on physical activity rather than reductions in sitting per se . The habitual nature of sedentary behaviour means that behaviour change is challenging . Trial Registration Controlled-Trials.com IS RCT Objective . To evaluate the relationship of physical activity ( PA ) and sedentary behaviour with  gestational weight gain ( GWG ) and birth weight . Design . Combined data from two prospect i ve studies : ( 1 ) nulliparous pregnant women without BMI restrictions and ( 2 ) overweight and obese pregnant women at risk for gestational diabetes . Methods . Daily PA and sedentary behaviour were measured with an accelerometer around 15 and at 32–35 weeks of gestation . The association between time spent in moderate-to-vigorous PA ( MVPA ) and in  sedentary activities  with GWG and birth weight was determined . Main outcome measures were GWG between 15 and 32 weeks of gestation , average GWG per week , and birth weight . Results . We studied 111 women . Early in pregnancy , 32 % of women spent ≥30 minutes/day in at least moderate PA versus 12 % in late pregnancy . No significant associations were found between time spent in MVPA or sedentary behaviour with GWG or birth weight . Conclusions . We found no relation  between MVPA and sedentary behaviour with GWG or birth weight . The small percentage of women meeting the recommended levels of PA indicates the need to inform and support pregnant women to maintain regular PA , as there seems to be no adverse effect on birth weight and maintaining PA increases overall health IMPORTANCE Women with a history of gestational diabetes mellitus ( GDM ) are at substantially increased risk of type 2 diabetes mellitus ( T2DM ) . The identification of important modifiable factors could help prevent T2DM in this high-risk population . OBJECTIVE To examine the role of physical activity and television watching and other sedentary behaviors  , and changes in these behaviors in the progression from GDM to T2DM . DESIGN , SETTING , AND PARTICIPANTS Prospect i ve cohort study of 4554 women from the Nurses ' Health Study II who had a history of GDM , as part of the ongoing Diabetes & Women 's Health Study . These women were followed up from 1991 to 2007 . EXPOSURES Physical activity and television watching and other sedentary behaviors  were assessed in 1991 , 1997 , 2001 , and 2005 . MAIN OUTCOMES AND MEASURE Incident T2DM identified through self-report and confirmed by supplemental question naires . RESULTS We documented 635 incident T2DM cases during 59,287 person-years of follow-up . Each 5-metabolic equivalent hours per week ( MET-h/wk ) increment of total physical activity , which is equivalent to 100 minutes per week of moderate-intensity physical activity , was related to a 9 % lower risk of T2DM ( adjusted relative risk [ RR ] , 0.91 ; 95 % CI , 0.88 - 0.94 ) ; this inverse association remained significant after additional adjustment for body mass index ( BMI ) . Moreover , an increase in physical activity was associated with a lower risk of developing T2DM . Compared with women who maintained their total physical activity levels , women who increased their total physical activity levels by 7.5 MET-h/wk or more ( equivalent to 150 minutes per week of moderate-intensity physical activity ) had a 47 % lower risk of T2DM ( RR , 0.53 ; 95 % CI , 0.38 - 0.75 ) ; the association remained significant after additional adjustment for BMI . The multivariable adjusted RRs ( 95 % CIs ) for T2DM associated with television watching of 0 to 5 , 6 to 10 , 11 to 20 , and 20 or more hours per week were 1 ( reference ) , 1.28 ( 1.04 - 1.59 ) , 1.41 ( 1.11 - 1.79 ) , and 1.77 ( 1.28 - 2.45 ) , respectively ( P value for trend < .001 ) ; additional adjustment for BMI attenuated the association . CONCLUSIONS AND RELEVANCE Increasing physical activity may lower the risk of progression from GDM to T2DM . These findings suggest a hopeful message to women with a history of GDM , although they are at exceptionally high risk for T2DM , promoting an active lifestyle may lower the risk Background Pregnancy is a period in the life of women that is often associated with decreased daily physical activity and /or exercise . However , maintaining adequate levels of daily physical activity during pregnancy is important for mother and child . Studies suggest that moderate daily physical activity and exercise during pregnancy are associated with reductions in the risk of gestational diabetes mellitus ( GDM ) . However , at present , physical activity is not routinely advised to pregnant women at risk for gestational diabetes in the Netherl and s. In FitFor2- study we aim to assess whether an exercise program can improve insulin sensitivity and fasting plasma glucose levels of women at high risk for gestational diabetes , assuming that this will lower their risk of gestational diabetes . Methods The FitFor2- study is a r and omised controlled trial . Women who visit one of the participating hospitals or midwifery practice s and who are at risk for gestational diabetes are eligible to participate . After baseline measurement they are r and omly allocated to in the intervention or control group . The intervention group receives an exercise program twice a week in addition to usual care . The exercise program consist of aerobic and strength exercises and takes place under close supervision of a physiotherapist . Data are collected at 15 , 24 and 32 weeks of pregnancy and 12 weeks after delivery . Primary maternal outcome measures are fasting plasma glucose and relative increase in insulin resistance . Primary neonatal outcome is birth weight . Secondary outcome measures are : maternal serum triglycerides , HDL , cholesterol , HbA1c , maternal weight gain during pregnancy , maternal physical activity level , foetal growth . Discussion If the FitFor2 intervention program proves to be effective , obstetricians and midwives should refer women at risk for GDM to a special exercise program . Exercise programs for pregnant women under supervision of an experienced trainer are already available in the Netherl and s , and these programs could be adjusted easily for this target group . Furthermore , the costs of these programs should be refunded by including them in the basic health care cost reimbursement schemes . Trial registration Background : Obesity in pregnancy is associated with fetal macrosomia , a raised neonatal fat mass and an increased risk of obesity and poor metabolic health in childhood which persists into adulthood . The offspring of obese women are more likely to be obese than the offspring of lean women when they become pregnant themselves , perpetuating a cycle of obesity and its associated negative metabolic consequences . Increasing physical activity during pregnancy could improve insulin sensitivity and reduce the risk of maternal and offspring adverse outcomes . The UK Pregnancy Better Eating and Activity Trial ( UPBEAT ) is a trial of a complex intervention design ed to improve pregnancy outcomes through dietary changes and physical activity .  Data from the pilot trial of 183 women were available for analysis . The relationship between the time spent at different physical activity levels and maternal and infant pregnancy outcomes was examined . Key Messages : Strong evidence exists that physical activity improves insulin sensitivity in non-pregnant population s , and lifestyle interventions of proven effectiveness in non-pregnant population s have been developed . Women who are active in pregnancy demonstrate better glucose control and favourable pregnancy outcomes . There is a lack of effective interventions to support obese pregnant women to be physically active . Conclusions : No difference was detected in objective ly measured physical activity between women r and omised to the intervention and control arms of the UPBEAT pilot trial . Light-intensity physical activity was lower in early pregnancy in women who delivered macrosomic infants . Maternal sedentary time at 35 - 36 weeks ' gestation was positively associated and moderate-intensity physical activity was inversely associated with neonatal abdominal circumference . Maternal physical activity is associated with infant birth weight and abdominal circumference and is an appropriate target for intervention to improve infant outcomes . The challenge remains to develop an effective intervention to support obese pregnant women to be physically active Background : Physical activity has been associated with decreased risk of  gestational diabetes mellitus .  Exp and ing on 2 previously published analyses of absolute exertion measures ( time spent and energy expended ) , we assessed the relation between perceived exertion during usual prepregnancy recreational physical activity and gestational diabetes . Methods : We analyzed data from a Washington State 1998–2002 case – control study ( 216 cases , 472 controls ) and a 1996–2002 prospect i ve cohort study ( 897 participants ) separately . We used logistic regression models to derive odds ratios ( ORs ) and 95 % confidence intervals ( CIs ) . Results : Among case – control participants , risk of gestational diabetes was markedly lower for women who reported very strenuous to maximal exertion in usual activity during the year before pregnancy versus those who reported negligible or minimal exertion ( adjusted OR = 0.19 ; CI = 0.15–0.50 ) . There was a direct inverse relation between perceived exertion and risk of gestational diabetes . This relation was also evident among the subset of participants who did not meet physical activity guidelines in the year before pregnancy . Similarly , the OR among cohort participants reporting very strenuous to maximal exertion was 0.57 ( 0.24–1.37 ) versus those reporting negligible to moderate exertion . Conclusions : These results suggest that risk of gestational diabetes is inversely related to the exertion perceived during recreational physical activity in the year before pregnancy . Perceived exertion may be a valuable addition to behavior and fitness measures in assessing relations between physical activity and pregnancy-related health outcomes Objectives The long-term consequences of  maternal physical activity during pregnancy for  offspring cardiovascular health are unknown . We examined the association of  maternal self-reported physical activity in pregnancy ( 18 weeks gestation ) with offspring cardiovascular risk factors at age 15 . Design Prospect i ve cohort study . Setting The Avon Longitudinal Study of Parents and Children ( ALSPAC ) . Participants 4665 maternal-offspring pairs ( based on a sample with multiple imputation to deal with missing data ) from the ALSPAC , a prospect i ve cohort based in the South West of Engl and with mothers recruited in pregnancy in 1991–1992 . Primary and secondary outcome measures Offspring cardiovascular risk factors at age 15 ; body mass index ( BMI ) , waist circumference , systolic blood pressure , diastolic blood pressure , glucose , insulin , low-density lipoprotein cholesterol , high-density lipoprotein cholesterol and triglycerides . Results Greater maternal physical activity  was associated with lower BMI , waist circumference , glucose and insulin in unadjusted analyses . The magnitude of associations was generally small with wide CIs , and most associations attenuated towards the null after adjusting for confounders . The strongest evidence of association after adjustment for confounders was for glucose , although the 95 % CI for this association includes the null ; a one SD greater physical activity during pregnancy was associated with a −0.013 mmol/L difference in offspring glucose levels ( equivalent to approximately one-third of a SD ; 95 % CI −0.027 to 0.001 mmol/L ) . Conclusions Our results suggest that maternal physical activity in pregnancy , measured at 18 weeks gestation , is unlikely to be an important determinant of later offspring cardiovascular health . There was some suggestion of association with offspring glucose , but given that all other associations ( including insulin ) were null after adjustment for confounders , this result should be interpreted with caution The potential relationship between daily physical activity and pregnancy outcome remains unclear because of the wide variation in study design s and physical activity assessment measures . We sought to prospect ively quantify the potential effects of the various domains of physical activity on selected birth outcomes in a large unselected population . The sample consisted of 11,759 singleton pregnancies from the Avon longitudinal study of parents and children , United Kingdom . Information on daily physical activity was collected by postal question naire for self-report measures . Main outcome measures were birth weight , gestational age at delivery , preterm birth and survival . After controlling for confounders , a sedentary lifestyle and paid work during the second trimester of pregnancy were found to be associated with a lower birth weight , while ‘ bending and stooping ’ and ‘ working night shifts ’ were associated with a higher birth weight . There was no association between physical exertion and duration of gestation or survival . Repetitive boring tasks during the first trimester was weakly associated with an increased risk of preterm birth ( < 37 weeks ) ( adjusted odds ratio [ OR ] = 1.25 , 95 % CI 1.04–1.50 ) . ‘ Bending and stooping ’ during the third trimester was associated with a reduced risk of preterm birth ( adjusted OR = 0.73 , 95 % CI 0.63–0.84 ) . Dem and ing physical activities do not have a harmful effect on the selected birth outcomes while a sedentary lifestyle is associated with a lower birth weight . In the absence of either medical or obstetric complications , pregnant women may safely continue their normal daily physical activities should they wish to do so Adults are sedentary for an alarming 9 to 10 hours per day ( 1 ) . Accordingly , the popular press has coined the phrase sitting is the new smoking to describe a current epidemic of developed nations ( 24 ) . Evidence indicates that sedentary time is associated with incident cardiovascular disease , incidence of cardiovascular diseaserelated risk factors , and mortality ( 5 , 6 ) . Of note , the risk conferred by prolonged sedentariness is eliminated only by high levels of moderate- to vigorous-intensity physical activity ( MVPA ) ( about 60 to 75 min/d ) , which exceed physical activity recommendations ( 7 , 8) . As such , sedentary behavior is now believed to represent a clinical ly important aspect of a person 's physical activity profile and is no longer considered simply the extreme low end of the physical activity continuum ( 5 ) . Studies linking sedentary behavior to health outcomes have relied almost exclusively on self-reported  sedentary time  , which is subject to reporting bias and measurement error ( 9 ) . A 2015 systematic review ( 5 ) identified only 1 study ( NHANES [ National Health and Nutrition Examination Survey ] ) that examined the association between objective ly measured sedentary time and health outcomes , a study limited by a small event rate ( 10 ) . New studies using NHANES data have since been published , with longer follow-up and higher event rates ( 1115 ) . However , some of these studies have reported an association between objective ly measured sedentary time and mortality ( 11 , 14 , 15 ) , but others have not ( 12 , 13 ) . Additional cohort studies are thus needed to rectify evidence gaps . Furthermore , studies using accelerometers to objective ly measure sedentary behavior conventionally operationalize sedentary time as the total number of sedentary minutes per day . This approach ignores patterns of accumulated sedentary behavior over time . For example , accumulation of sedentary time in a few long bouts or many short bouts represents 2 distinct patterns of sedentary time accrual . Experimental studies have shown that acute periods of prolonged , uninterrupted sedentary behavior cause greater detrimental cardiometabolic effects than sedentary behavior that is periodically interrupted ( 1618 ) , suggestive that it is not just total sedentary time that is relevant to health outcomes , but also the manner in which it is accumulated . Few longitudinal studies , however , have explored the association between prolonged , uninterrupted sedentary behavior and mortality to corroborate these findings . To inform guidelines on reducing sedentary behavior ( target reductions in overall sedentary time or target interruption of prolonged sedentary bouts ) , evidence from prospect i ve studies is needed to 1 ) confirm the association between total sedentary time and mortality using objective measures , 2 ) determine whether prolonged sedentary bouts confer risk for death , and 3 ) eluci date whether the total volume of sedentary time and its pattern of accumulation individually or jointly contribute to risk for death . The purpose of this study , therefore , was to examine the association between objective ly measured sedentary time ( both total volume and accrual in prolonged bouts ) and all-cause mortality in a national cohort of U.S. middle-aged and older adults enrolled in the REGARDS ( Reasons for Geographic and Racial Differences in Stroke ) study . Methods Study Population REGARDS is a population -based study design ed to examine racial and regional disparities in stroke . It comprises 30239 white and black adults aged 45 years or older enrolled between 2003 and 2007 from across the contiguous United States ( 19 , 20 ) . Detailed design and methods for REGARDS are described elsewhere ( 21 ) . Briefly , demographic and cardiovascular risk factor data were collected by telephone interview and an in-home physical assessment on enrollment . A detailed summary of baseline measures is provided in the Supplement . Participants ( or their proxies ) were then followed for 6-month intervals to ascertain vital status . Objective measurements of sedentary behavior were collected from active REGARDS participants from 2009 to 2013 ( mean time from study enrollment , 5.7 years [ SD , 1.5 ] ; range , 1.9 to 9.5 years ) ( 22 ) . A total of 7985 participants adhered to accelerometer wear requirements ( 4 days with accelerometer wear 10 hours ) , provided follow-up data , and were available for the current analyses ( Supplement Figure 1 ) . Supplement Table 1 shows the characteristics of included versus excluded REGARDS participants . The REGARDS study protocol was approved by the institutional review boards of participating institutions . All participants provided informed consent . Supplement . Supplementary Material Accelerometer Data Collection Methods for accelerometer data collection are described elsewhere ( 22 ) . Briefly , participants were fitted with an Actical ( Philips Respironics ) accelerometer secured to their right hip using a nylon belt and were instructed to wear the device during waking hours for 7 consecutive days . The Actical had been vali date d formeasurement of physical activity and sedentary behavior and was shown to have acceptable reliability ( 2325 ) . Activity counts were summed over 1-minute epochs . Nonwear periods were defined as at least 150 consecutive minutes of 0 activity counts . This nonwear algorithm was previously vali date d against daily log sheets in REGARDS participants ( 26 ) . Measurements of 0 to 49 , 50 to 1064 , and at least 1065 counts per minute were defined as sedentary behavior , light-intensity physical activity , and MVPA , respectively , as determined in a laboratory-based calibration study ( 27 ) . A sedentary bout was defined as consecutive minutes in which the accelerometer registered fewer than 50 counts per minute . A sedentary break was defined as at least 1 minute in which 50 or more counts per minute were registered after a sedentary bout . Both sedentary bouts and breaks were exclusively continuous periods , with no interruptions or nonwear intervals allowed in the definition . Outcome Ascertainment All-cause mortality was the primary outcome , defined as any death after completion of the accelerometer protocol regardless of cause . Date s of death were confirmed through review of death certificates , medical records , and administrative data bases . Deaths through 4 September 2015 were included in the current analysis . Statistical Analysis Sedentary and physical activity variables were averaged across compliant days ( 10 hours of wear ) . Because of a high correlation between total sedentary time and wear time ( Supplement Figure 2 ) , we corrected for the influence of wear time by st and ardizing total sedentary time to 16 hours of wear time per day using the residuals obtained when regressing total sedentary time on wear time ( see Methods section of the Supplement ) ( 2830 ) . Participants were stratified into quartiles according to total sedentary time and , separately , mean sedentary bout duration ( a measure of overall prolonged , uninterrupted sedentary behavior ) . Cox proportional hazards regression modeling was used to calculate the hazard ratio ( HR ) for all-cause mortality associated with quartiles of total sedentary time ( and separately , mean sedentary bout length ) . Crude HRs were initially calculated . Subsequent HRs were calculated after adjustment for age , race , sex , region of residence , education , and season the accelerometer was worn ( model 1 ) , with further adjustment for current smoking , alcohol use , body mass index ( BMI ) , diabetes , hypertension , dyslipidemia , estimated glomerular filtration rate less than 60 mL/min/1.73 m2 , atrial fibrillation , history of coronary heart disease , and history of stroke ( model 2 ) . Models were additionally adjusted for MVPA expressed continuously ( model 3 ) . Tests for linear trend across quartiles were conducted by including the quartile for each participant as an ordinal variable in regression models . Proportional hazards assumptions were confirmed with a Kolmogorov-type supremum test ( 31 ) . The above analyses were then repeated in a fully adjusted model , testing interactions for age ( < 65 and 65 years ) , sex ( male and female ) , race ( black and white ) , BMI category ( normal weight and overweight or obese ) , and MVPA category ( < 150 min/wk and 150 min/wk ) . As a secondary analysis , we examined the continuous doseresponse relationship between each sedentary characteristic and all-cause mortality in a fully adjusted model ( model 3 ) using restricted cubic splines ( 32 ) . Cubic polynomials were fitted with the mean of each sedentary characteristic set as the reference and knots placed at the 5th , 35th , 65th , and 95th percentiles ( 33 ) . Nonlinear associations were evaluated using the likelihood ratio test . For nonlinear associations , spline models were used to describe the associations and when the association was determined to be linear , a linear model was used . Because of multicollinearity between total sedentary time and mean sedentary bout duration ( r= 0.61 ) , both variables were not included in the same model . Alternatively , to examine the individual and joint associations of total sedentary time and prolonged , uninterrupted sedentary behavior with mortality , participants were classified into 4 categories : low total sedentary time ( < 750 min/d ) and low prolonged sedentary bout time ( < 10 min/bout ) , low total sedentary time  and high prolonged sedentary bout time  ( 10 min/bout ) , high total sedentary time  ( 750 min/d ) and low prolonged sedentary bout time , and high total sedentary time and high prolonged sedentary bout time . Hazard ratios for all-cause mortality were calculated for each joint category in comparison with the lowlow group in a fully adjusted model ( model 3 ) . Thresholds for total sedentary time ( 750 min/d ) and mean sedentary bout duration ( 10 min/bout ) were selected on the basis of the restricted cubic splines and were confirmed using a method described by Contal and O'Quigley ( see Methods section of the Supplement ) ( 34 ) . To allow for the possibility that sedentary bouts OBJECTIVE To examine the potential effect of low-risk pregnancy on women 's recreational activity patterns and to explore pregnant women 's beliefs and information sources regarding physical exercise participation . DESIGN Preliminary , prospect i ve survey SETTING Participants ' homes in the East Midl and s , UK . PARTICIPANTS Fifty-seven nulliparous , pregnant women . MEASUREMENTS Levels of  maternal physical activity participation were assessed by semi-structured interview at 16 , 25 , 34 and 38 weeks gestation . The modified Baecke question naire provided a measure of women 's habitual sport and leisure activities in the 12 months prior to pregnancy . A 10-item scale assessed maternal beliefs regarding the importance of physical activity in pregnancy . The fetal health locus of control scale measured the extent to which women believed their own behaviour , the behaviour of others and /or chance would influence fetal health . Open-ended questions assessed women 's information sources . FINDINGS Fourteen of the 36 ( 39 % ) women who reported participating in some form of weekly exercise before pregnancy did not report pursuing any similar activities during pregnancy .  Rest and relaxation  were perceived as being significantly more important during pregnancy than was regular exercise or the maintenance of an active lifestyle . Fifty-five respondents ( 96 % ) indicated that they had received advice about physical activity at least once during pregnancy . At 16 weeks gestation , women obtained most of their information from books and magazines . Between 25 and 38 weeks gestation , most advice came from family and friends . Participants who reported receiving this advice were significantly older , more educated and of a higher activity level pre-pregnancy . KEY CONCLUSIONS Levels of maternal exercise  may decline during pregnancy both as a result of the physical changes of pregnancy and from a combination of social and psychological factors . Present health education may be failing to correct inaccurate perceptions of the risks associated with physical exercise in pregnancy . IMPLICATION S FOR PRACTICE Improving the quantity and quality of information related to physical exercise has the potential to correct inaccurate perceptions and confer several benefits on maternal and fetal health . Effective intervention strategies should focus not only on the pregnant woman but also extend to her family , friends and exercise provider PURPOSE The present study examined the effects of exercise on physical and psychological variables in sedentary primigravidae ( PRA ) . METHODS A total of nine women r and omly assigned to an exercise ( E ) ( mean age = 31.3 + /- 3.1 yr ) and six subjects r and omly assigned to a control ( C ) group ( mean age = 27.8 + /- 3.1 yr ) fulfilled all requirements for the study . Exercise included a variety of exercise activities performed to a target heart rate of 150 - 156 beats x min(-1 ) , three times per week for 15 wk . RESULTS Results showed no significant differences between E and C groups in physical characteristics initially . A repeated measures ANOVA showed a significant group effect ( P < 0.05 ) and a significant group by time interaction ( P = 0.001 ) with the E group showing a significantly longer amount of time on the PWC150 test than the C group . There was no significant group , time , or group by time interaction for lactate accumulation . This occurred , despite the fact that the E group spent 56 % longer on the PWC150 test and the C group spent 30 % less time on the same test at the conclusion of the study . Finally , the E group in comparison to the C group showed more favorable improvements in several items related to health and well-being on the Body Cathexis Scale . There were no significant differences between E and C groups in any pregnancy outcome measures . All babies were delivered healthy  at term . CONCLUSIONS These data suggest that a vigorous exercise program can lead to significant improvements in aerobic fitness at similar lactate concentrations compared to a control group and can be well tolerated by low risk sedentary PRA without any deleterious effects occurring to herself or unborn child The discovery of a link between in utero experience and later metabolic and cardiovascular disease is one of the most important advances in epidemiology research of recent years . There is now increasing evidence that alterations in the fetal environment have long-term consequences on metabolic and endocrine pathophysiology in adult life . This process has been termed " fetal programming , " and we have shown that undernutrition of the mother during gestation leads to obesity , hypertension , hyperphagia , hyperinsulinemia , and hyperleptinemia in offspring . Using this model of maternal undernutrition throughout pregnancy , we investigated whether prenatal influences may lead to alterations in postnatal locomotor behavior , independent of postnatal nutrition . Virgin Wistar rats were time mated and r and omly assigned to receive food either ad libitum ( ad libitum group ) or at 30 % of ad libitum intake ( undernourished group ) . Offspring from UN mothers were significantly smaller at birth than AD offspring . At weaning , offspring were assigned to one of two diets [ control or hypercaloric ( 30 % fat ) ] . At ages of 35 days , 145 days , and 420 days , voluntary locomotor activity was assessed . At all ages studied , offspring from undernourished mothers were significantly less active than offspring born of normal birth weight for all parameters measured , independent of postnatal nutrition . Sedentary behavior in programmed offspring was exacerbated by postnatal hypercaloric nutrition . This work is the first to clearly separate prenatal from postnatal effects and shows that lifestyle choices themselves may have a prenatal origin . We have shown that predispositions to obesity , altered eating behavior , and sedentary activity are linked and occur independently of postnatal hypercaloric nutrition . Moreover , the prenatal influence may be permanent as offspring of undernourished mothers were still significantly less active compared with normal offspring at an advanced adult age , even in the presence of a healthy diet throughout postnatal life BACKGROUND Although epidemiologic studies have shown associations between sedentary behavior and mortality , few have focused on older women with adequate minority representation and few have controlled for both physical activity and functional status . PURPOSE The objective of this study was to determine the relationship between sedentary time and total ; cardiovascular disease ( CVD ) ; coronary heart disease ( CHD ) ; and cancer mortality in a prospect i ve , multiethnic cohort of postmenopausal women . METHODS The study population included 92,234 women aged 50 - 79 years at baseline ( 1993 - 1998 ) who participated in the Women 's Health Initiative Observational Study through September 2010 .  Self-reported sedentary time  was assessed by question naire and examined in 4 categories ( ≤4 , > 4 - 8 , ≥8 - 11 , > 11 hours ) . Mortality risks were examined using Cox proportional hazard models adjusting for confounders . Models were also stratified by age , race/ethnicity , body mass index , physical activity , physical function , and chronic disease to examine possible effect modification . Analyses were conducted in 2012 - 2013 . RESULTS The mean follow-up period was 12 years . Compared with women who reported the least sedentary time , women reporting the highest sedentary time had increased risk of all-cause mortality in the multivariate model ( HR=1.12 , 95 % CI=1.05 , 1.21 ) . Results comparing the highest versus lowest categories for CVD , CHD , and cancer mortality were as follows : HR=1.13 , 95 % CI=0.99 , 1.29 ; HR=1.27 , 95 % CI=1.04 , 1.55 ; and HR=1.21 , 95 % CI=1.07 , 1.37 , respectively . For all mortality outcomes , there were significant linear tests for trend . CONCLUSIONS There was a linear relationship between greater amounts  of sedentary time and mortality risk after controlling for multiple potential confounders
Increased time in sedentary behaviour was significantly associated with higher levels of C Reactive Protein and LDL Cholesterol , and a larger newborn abdominal circumference .
Discrepancies were found in associations of sedentary behaviour with gestational weight gain , hypertensive disorders , and birth weight .
No consistent associations were found between sedentary behaviour and other variables such as gestational diabetes .
Conclusions Our review highlights the significant time spent in sedentary behaviour during pregnancy , and that sedentary behaviour may impact on pregnancy outcomes for both mother and child .
Background In the general population , at least 50 % of time awake is spent in sedentary behaviours .
Sedentary behaviours are activities that expend less energy than 1.5 metabolic equivalents , such as sitting .
The amount of time spent in sedentary behaviours is a risk factor for diseases such as type 2 diabetes , cardiovascular disease , and death from all causes .
Even individuals meeting physical activity guidelines are at a higher risk of premature death and adverse metabolic outcomes if they sit for extended intervals .
The associations between sedentary behaviour with type 2 diabetes and with impaired glucose tolerance are stronger for women than for men .
It is not known whether sedentary behaviour in pregnancy influences pregnancy outcomes , but if those negative outcomes observed in general adult population also occur in pregnancy , this could have implication s for adverse outcomes for mothers and offspring .
We aim ed to determine the proportion of time spent in sedentary behaviours among pregnant women , and the association of sedentary behaviour with pregnancy outcomes in mothers and offspring .