Higher Light Physical Activity Research Articles

Associations Between Biodiversity, Forest Characteristics, Distance to Blue Space and Accelerometer-Measured Physical Activity—Northern Finland Birth Cohort 1966 Study

We studied how the quantity and quality of residential green spaces and distance to different types of blue spaces are associated with the accelerometer-measured physical activity (PA) among adults with different levels of total daily PA. The associations of the participants’ socio-demographic and personal characteristics and environmental features with light PA (LPA) and moderate-to-vigorous PA (MVPA) were analyzed using linear mixed models (n = 5470). The results indicated that greater residential forest area was associated with higher LPA among those with high level of total daily PA and with less MVPA among those with low level of total daily PA. Environments with high tree stand structure diversity or close to sea were associated with higher MVPA in high PA group. Varied natural environment can encourage leisure time activities in nearby nature, but individuals’ personal and socioeconomic variables seemed to be more strongly associated with LPA and MVPA than environmental characteristics.

Physical activity levels in patients with chronic venous insufficiency.

Increasing the levels of physical activity (PA) is widely recommended for people with chronic venous insufficiency (CVI). However, studies investigating the patterns of PA and adherence to PA guidelines using objective measures are lacking. The primary aim was to examine the patterns of PA and adherence to PA guidelines among patients with CVI. A secondary aim was to identify whether adherence to PA recommendations differed according to patients' sociodemographic and clinical characteristics. This cross-sectional study included 96 patients with CVI with Clinical-Etiology-Anatomy-Pathology (CEAP) C3 to C6 (69.1% women 59 ± 11years; 51.5% C5-C6 on CEAP classification). Objective time spent in PA was measured by a triaxial accelerometer. To examine adherence to PA guidelines, patients were grouped as meeting (or) the recommendations if they had at least 150min/week of moderate to vigorous PA. Sociodemographic and clinic characteristics were obtained by self-report. Binary logistic regression was employed to examine whether sociodemographic and clinical characteristics were associated with adherence to PA guidelines. T-tests were employed to compare PA levels at different intensities according to patients' age. Patients spent an average of 311.4 ± 91.5min/week, 42.1 ± 28.0min/week, and 19.8 ± 17.8min/week in low-light PA, high-light PA, and moderate-to-vigorous PA, respectively. The proportion of patients meeting PA recommendations was 36.2%, and older patients had lower odds (OR = 0.94; 95%CI: 0.89 to 0.99). Additional analysis reinforced that by showing lower time in high-light PA (51.2 ± 30.0min/day vs. 31.9 ± 21.8min/day; p = .001) and moderate-to-vigorous PA (24.3 ± 15.8min/day vs. 14.8 ± 18.8min/day; p = .012) among older patients than their peers younger. Our findings showed that 36,2% of CVI patients met PA recommendations, with lower odds found among older patients. Public health interventions to enhance PA engagement among CVI patients should prioritize those who are older.

Accelerometer-based sedentary time, light physical activity, and moderate-to-vigorous physical activity from childhood with arterial stiffness and carotid IMT progression: A 13-year longitudinal study of 1339 children.

We examined the longitudinal associations of sedentary time (ST), light physical activity (LPA), and moderate-to-vigorous PA (MVPA) from childhood with carotid-femoral pulse wave velocity (cfPWV), a measure of arterial stiffness and carotid intima-media thickness (cIMT). We studied 1339 children, aged 11 years from Avon Longitudinal Study of Parents and Children, UK, followed up for 13 years. Accelerometer-based ST, LPA, and MVPA were assessed at ages 11, 15, and 24 years clinic visits. cfPWV and cIMT were measured with Vicorder and ultrasound, respectively, at ages 17 and 24 years. Among 1339 [56.4% female] participants, mean ST increased from ages 11 through 24 years, while mean LPA and MVPA decreased. Persistently high ST tertile from childhood was associated with increased cfPWV progression, effect estimate 0.047 m/s; [(95% CI 0.005 to 0.090); p = 0.030], but not cIMT progression. Persistently high LPA tertile category was associated with decreased cfPWV progression in males -0.022 m/s; [(-0.028 to -0.017); p < 0.001] and females -0.027 m/s; [(-0.044 to -0.010); p < 0.001]. Cumulative LPA exposure decreased the odds of progressively worsening cfPWV [Odds ratio 0.994 (0.994-0.995); p < 0.0001] and cIMT. Persistent exposure to ≥60 min/day of MVPA was paradoxically associated with increased cfPWV progression in males 0.053 m/s; [(0.030 to 0.077); p < 0.001] and females 0.012 m/s; [(0.002 to 0.022); p = 0.016]. Persistent exposure to ≥60 min/day of MVPA was inversely associated with cIMT progression in females -0.017 mm; [(-0.026 to -0.009); p < 0.001]. LPA >3 h/day from childhood may attenuate progressively worsening vascular damage associated with increased ST in youth.

The Interactive Effects of Sedentary Time, Physical Activity, and Fat Mass on Insulin Resistance in the Young Population.

Recent evidence in 9-year-old children with overweight/obesity followed up for 7 years until late adolescence concluded that increased physical activity (PA) decreased the risk of high fasting glucose, low insulin sensitivity, and secretion. However, whether this effect persists until young adulthood is unknown. This observational study examined the effects of cumulative sedentary time (ST), light PA (LPA), and moderate-to-vigorous (MVPA) on glucose, insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) in 11-year-old children followed up for 13 years until young adulthood. Altogether 792 children from the Avon Longitudinal Study of Parents and Children, UK who had data on at least two measures of accelerometer-based movement behaviour during ages 11, 15, and 24 years follow-up clinic visits with complete fasting glucose, insulin, and HOMA-IR measures at ages 15, 17, and 24 years were included. ST, LPA, and MVPA were measured with an accelerometer. Cumulative ST from ages 11-24 years was associated with increased odds (odds ratio 1.20 [95% CI 1.00-1.44] p=0.047) and cumulative LPA was associated with the decreased odds of hyperinsulinemia (0.80 [0.66-0.96] p=0.017) among participants with overweight/obesity. Cumulative MVPA was inversely associated with insulin but after accounting for the mediating role of fat mass, MVPA effect on lowering insulin decreased by 58% resulting in statistical non-significance. In the temporal path analyses, among participants with overweight/obesity, higher glucose at age 15 years was associated with lower LPA and MVPA at 24 years. Higher LPA at 15 years was associated with lower insulin and HOMA-IR at 24 years and vice-versa. Promoting LPA while decreasing body fat mass and ST may be considered crucial intervention targets to attenuate the risk of hyperinsulinemia and insulin resistance from childhood through young adulthood.

Mediating effect of fat mass, lean mass, blood pressure and insulin resistance on the associations of accelerometer-based sedentary time and physical activity with arterial stiffness, carotid IMT and carotid elasticity in 1574 adolescents

This study examined the mediating effect of total body fat mass, lean mass, blood pressure (BP) and insulin resistance on the associations of sedentary time (ST), light physical activity (LPA) and moderate-to-vigorous PA (MVPA) with carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (cIMT) and carotid elasticity in 1574 adolescents from the Avon Longitudinal Study of Parents and Children birth cohort, UK. ST, LPA and MVPA were assessed with ActiGraph accelerometer. ST and LPA were sex-categorised in tertiles as low (reference), moderate and high, while MVPA was categorised as <40 min/day (reference), 40–<60 min/day and ≥60 min/day. cfPWV, cIMT and carotid elasticity were measured with Vicorder and ultrasound. Fat mass and lean mass were assessed with dual-energy X-ray absorptiometry and homeostatic model assessment of insulin resistance (HOMA-IR) was computed. Mediation analyses structural equation models and linear mixed-effect models adjusted for cardiometabolic and lifestyle factors were conducted. Among 1574 adolescents [56.2% female; mean (SD) age 15.4 (0.24) years], 41% males and 17% females accumulated ≥60 min/day of MVPA. Higher ST was associated with lower cIMT partly mediated by lean mass. Higher LPA (standardized β = −0.057; [95% CI −0.101 to −0.013; p = 0.014]) and the highest LPA tertile were associated with lower cfPWV. BP had no significant mediating effect movement behaviour relations with vascular indices. Lean mass partially mediated associations of higher MVPA with higher cIMT (0.012; [0.007–0.002; p = 0.001], 25.5% mediation) and higher carotid elasticity (0.025; [0.014–0.039; p = 0.001], 28.1% mediation). HOMA-IR mediated the associations of higher MVPA with higher carotid elasticity (7.7% mediation). Engaging in ≥60 min/day of MVPA was associated with higher carotid elasticity. In conclusion, higher LPA was associated with lower arterial stiffness, but higher MVPA was associated with thicker carotid wall explained by higher lean mass.

Isotemporal Substitution of Sedentary Time With Physical Activity Among Middle-Aged and Older Latinos: Effects on Episodic Memory.

To examine the estimated effects of substituting 30min of sedentary time with low-light physical activity (LLPA) and high-light physical activity (HLPA) on episodic memory, executive functioning, and working memory among middle-aged and older Latinos. A cross-sectional study. Chicago and Chicagoland suburbs. Middle-aged and older Latinos (n = 61). Accelerometer-assessed physical activity. A cognitive battery was administered to assess episodic memory, executive function, and working memory. Isotemporal substitution analyses were conducted, where unstandardized coefficients from linear regression models were used to examine the substitution effect of replacing sedentary time with LLPA and HLPA. Substitution of sedentary time with LLPA was associated with better episodic memory (Immediate recall, B = .947, P = .008; Delayed recall, B = .857, P = .013). No other significant substitution effects were present. Middle-aged and older Latinos who replace sedentary time with LLPA may have better episodic memory. Future studies may target light physical activity to address cognition disparities and can inform the development of physical activity interventions that are appealing and accessible for Latinos.

Association of accelerometer-measured physical activity intensity, sedentary time, and exercise time with incident Parkinson’s disease

Evidence regarding the association between physical activity and Parkinson’s disease (PD) risk is generally limited due to the use of self-report questionnaires. We aimed to quantify the separate and combined effects of accelerometer-measured light physical activity (LPA), moderate-to-vigorous physical activity (MVPA), sedentary time and exercise timing with incident PD. 96,422 participants without prior PD and with usable accelerometer data were included from UK Biobank. Time spent in sedentary activity, LPA, MVPA, and exercise timing were estimated using machine learning models. The study outcome was incident PD. Over a median follow-up duration of 6.8 years, 313 participants developed PD. There was a L-shaped association for LPA and MVPA, and a reversed L-shaped association for sedentary time, with the risk of incident PD (all P for nonlinearity < 0.001). Similar trends were found across three time-windows (morning, midday-afternoon, and evening). Compared with those with both low LPA (<3.89 h/day) and low MVPA (<0.27 h/day), the adjusted HR (95% CI) of PD risk was 0.49 (0.36–0.66), 0.19 (0.36–0.66) and 0.13 (0.09–0.18), respectively, for participants with high MVPA only, high LPA only, and both high LPA and high MVPA. Moreover, participants with both low LPA and high sedentary time (≥9.41 h/day) (adjusted HR, 5.59; 95% CI: 4.10–7.61), and those with both low MVPA and high sedentary time (adjusted HR, 3.93; 95% CI: 2.82–5.49) had the highest risk of incident PD. In conclusion, regardless of exercise timing (morning, midday-afternoon, and evening), there was an inverse association for accelerometer-measured MVPA and LPA, and a positive association for sedentary time, with incident PD.

Comparison of children's physical activity profiles before and after COVID-19 lockdowns: A latent profile analysis.

Physical activity is important for children's health, but moderate to vigorous physical activity (MVPA) declines with age. COVID-19 lockdowns resulted in reduced MVPA and increased sedentary time among children. Characterising children's activity patterns may help identify groups who are most likely to be inactive post-lockdown. Data were combined from a pre-COVID-19 cohort study on children aged 5-6 years (Year1: n = 1299), 8-9 years (Year4: n = 1223) and 10-11 years (Year6: n = 1296) and cross-sectional post-lockdown data from a natural experiment on 10-11-year-olds in 2021 (Year6-W1: n = 393) and 2022 (Year6-W2: n = 436). The proportions of time spent in MVPA, light physical activity (LPA) and sedentary time on weekdays and weekends were derived from accelerometer data. Latent class analysis was used to identify activity profiles pre and post-lockdown, and estimate pre-COVID-19 transitions between Year4 and Year6. We identified six pre-COVID-19 activity profiles in Year6, including a new profile characterised by very low MVPA and high sedentary time (19% of children). There was substantial movement between profiles at Year4 and Year6, with 45% moving to a profile with lower MVPA. Likelihood ratio tests suggested differences in Year6 activity profiles pre and post-lockdown, with a new post-lockdown profile emerging characterised by higher LPA. The percentage of children in the least active profiles (where under 20% meet UK physical activity guidelines), rose post-lockdown, from 34% pre-COVID-19 to 50% in 2021 and 40% in 2022. We also saw gender and socioeconomic gaps widen, and increased separation between high and low physical activity levels. Children's physical activity has changed post-COVID-19, in terms of who is being active and how. The impact varies by activity profile, which is influenced by gender and socio-economic position. A greater understanding of these differences and targeting of low active groups is needed to increase both individual and population levels of physical activity.

Physical activity, residential greenness, and cardiac autonomic function.

This population-based study examines the associations between physical activity (PA), residential environmental greenness, and cardiac health measured by resting short-term heart rate variability (HRV). Residential greenness of a birth cohort sample (n = 5433) at 46 years was measured with normalized difference vegetation index (NDVI) by fixing a 1 km buffer around each participant's home. Daily light PA (LPA), moderate PA (MPA), vigorous PA (VPA), and the combination of both (MVPA) were measured using a wrist-worn accelerometer for 14 days. Resting HRV was measured with a heart rate monitor, and generalized additive modeling (GAM) was used to examine the association between PA, NDVI, and resting HRV. In nongreen areas, men had less PA at all intensity levels compared to men in green areas. Women had more LPA and total PA and less MPA, MVPA, and VPA in green residential areas compared to nongreen areas. In green residential areas, men had more MPA, MVPA, and VPA than women, whereas women had more LPA than men. GAM showed positive linear associations between LPA, MVPA and HRV in all models. Higher LPA and MVPA were significantly associated with increased HRV, irrespective of residential greenness. Greenness was positively associated with PA at all intensity levels in men, whereas in women, a positive association was found for LPA and total PA. A positive relationship of PA with resting HRV and greenness with PA was found. Residential greenness for promoting PA and heart health in adults should be considered in city planning.

Associations of Accelerometer-Measured Physical Activity and Sedentary Time With All-Cause Mortality by Genetic Predisposition for Longevity.

The goal of this study was to examine associations between accelerometer-measured physical activity (PA) and sedentary time (ST) with mortality by a genetic risk score (GRS) for longevity. Among 5,446 women, (mean [SD]: age, 78.2 [6.6]years), 1,022 deaths were observed during 33,350 person-years of follow-up. Using multivariable Cox proportional hazards models, higher light PA and moderate to vigorous PA were associated with lower mortality across all GRS for longevity categories (low/medium/high; all ptrend < .001). Higher ST was associated with higher mortality (ptrend across all GRS categories < .001). Interaction tests for PA and ST with the GRS were not statistically significant. Findings support the importance of higher PA and lower ST for reducing mortality risk in older women, regardless of genetic predisposition for longevity.

Association of Accelerometer-Measured Physical Activity and Sedentary Behavior With Incident Cardiovascular Disease, Myocardial Infarction, and Ischemic Stroke: The Women's Health Study.

Background Few studies have investigated associations of acclerometer-based assessments of physical activity (PA) and sedentary behavior (SB) with incidence of cardiovascular disease (CVD) and its components. This prospective cohort study assessed the associations of accelerometer-measured PA and SB with total CVD, myocardial infarction, and ischemic stroke (IS). Methods and Results The authors included 16 031 women aged 62 years and older, free of CVD, with adherent accelerometer wear (≥10 hours/day for ≥4 days) from the Women's Health Study (mean age, 71.4 years [SD, 5.6 years]). Hip-worn ActiGraph GT3X+ accelerometers measured total volume of PA (total average daily vector magnitude), minutes per day of high-light PA and moderate to vigorous PA (MVPA), and SB. Women reported diagnoses of CVD, which were adjudicated using medical records and death certificates. Hazard ratios (HRs) were estimated for each exposure, and 95% CIsusing Cox proportional hazards models were adjusted for accelerometer wear time, age, self-reported general health, postmenopausal hormone therapy, smoking status, and alcohol use. The hypothetical effect of replacing 10 minutes/day of SB or high-light PA with MVPA on CVD incidence was assessed using adjusted isotemporal substitution Cox models. Over a mean of 7.1 years (SD, 1.6 years) of follow-up, 482 total CVD cases, 107 myocardial infarction cases, and 181 IS cases were diagnosed. Compared with the lowest quartiles of total average daily vector magnitude and MVPA (≤60 minutes), women who were in the highest quartiles (>120 minutes of MVPA) had a 43% (95% CI, 24%-58%) and 38% (95% CI, 18%-54%) lower hazard of total CVD, respectively. Estimates were similar for total average daily vector magnitude and MVPA with IS, but PA was not associated with myocardial infarction overall. High-light PA was not associated with any CVD outcomes. Women who spent <7.4 hours sedentary per day had a 33% (95% CI,11%-49%) lower hazard of total CVD compared with those who spent ≥9.5 hours sedentary. Replacing 10 minutes of SB with MVPA was associated with a 4% lower incidence of total CVD (HR, 0.96 [95% CI, 0.93-0.99]). Conclusions Accelerometer-assessed total PA and MVPA were inversely associated with total CVD and IS incidence, and SB was directly associated with total CVD; high-light PA was not related to CVD.

Light Physical Activity Relates To Insulin Sensitivity And Earlier Time Of Day In Metabolic Syndrome

PURPOSE: Low insulin sensitivity is linked to metabolic syndrome (MetS). However, whether the time of day when light physical activity (LPA) occurs affects insulin sensitivity is unclear. We tested the relationship between LPA time of day and insulin sensitivity in MetS. METHODS: Thirty adults with MetS were classified as morning (MOR, n = 11, 9F), midday (MID, n = 9, 6F), or afternoon (AFT, n = 10, 6F) by active LPA time using 7-d tri-axial hip-worn accelerometry (Actigraph). Time of day was defined by which part of the day had the highest percentage (>50%) of LPA. Peripheral insulin sensitivity (M-value between 90-120 min) was measured using a 2-hr hyperinsulinemic-euglycemic clamp (40 mU/m2/min, 90 mg/dl), while hepatic (HOMA-IR), and adipose (Adipose-IR) insulin resistance were estimated from fasting glucose, FFA, and insulin, respectively. Aerobic fitness (VO2max), anthropometrics (BMI, waist circumference), and inflammation (TNF-α, CRP and IL-8 at 0 and 120 min) were also examined. RESULTS: There were no differences amongst groups in age (P = 0.60), ATP III criteria (P = 0.91), or VO2max (P = 0.76). While time in sedentary (P = 0.44) and moderate-to-vigorous activity (P = 0.66) were similar amongst groups, MOR (21.3 ± 1.7%, P = 0.03) and MID (21.1 ± 1.3%, P = 0.01) had increased time in LPA compared to AFT (16.5 ± 1.2%). Further, MOR had a lower BMI (33.1 ± 1 vs. 38.6 ± 1.8 vs. 41 ± 2 kg/m2, P = 0.004) and waist circumference (107.9 ± 1.8 vs. 115.3 ± 3.8 vs. 123.1 ± 5.4 cm, P = 0.02). Although clamp-derived insulin sensitivity (P = 0.43), HOMA-IR (P = 0.30), and adipose-IR (P = 0.81) were similar across groups, higher LPA (%) related to increased peripheral insulin sensitivity (r = 0.33, P = 0.04) and lower adipose-IR (r = -0.36, P = 0.02). There were no group differences in fasting or change (i.e. 120-0 min) in TNF-α (P = 0.55), CRP (P = 0.41) or IL-8 (P = 0.07). However, higher LPA (%) related to insulin stimulated reductions in IL-8 (r = -0.42, P = 0.01). These changes in IL-8 also correlated with a higher adipose-IR (r = 0.37, P = 0.03). CONCLUSION: Time spent in LPA relates to insulin sensitivity and earlier times of day. Future work should look at whether time of day influences body weight regulation and cardiovascular health to optimize disease prevention/treatment. Funding: NIH RO1-HL130296

Can discrepancies between impulsive and reflective processes be associated with movement behavior among the elderly? The facilitating role of inhibitory control

Physical activity participation remains a global public health challenge, with 8 out of 10 older adults failing to meet the minimum physical activity recommendations, and it is also associated with an increased risk of cardiovascular disease, cognitive impairment, and mortality. Strategies to promote physical activity are primarily focused on socio-cognitive factors, and their effectiveness is limited. According to dual-process theories, physical activity is related with impulsive/implicit (i.e., emotions) and reflective/explicit (i.e., perceived advantage) processes; however, implicit-explicit discrepancy (IED) may impair movement behavior. In addition, cognitive inhibitory control may have r direct relationship with IED situations since it determines which of these processes predominates in the regulation of individual's behavior. Nonetheless, these outcomes in physical activity behavior among older adults have received little attention. In this study, we associate IED with physical activity and sedentary behavior as measured by accelerometers, and investigate the moderator role of inhibitory control in this association. In this cross-sectional study, 94 older adults were assessed for implicit and explicit attitudes, inhibitory control, and movement behavior using accelerometers over the course of seven days. A higher magnitude of the IED was linked to less moderate-to-vigorous physical activity (MVPA) and daily steps. Interestingly, a higher light physical activity was associated with a direction of the IED with more positive explicit attitudes. Furthermore, in older adults with higher inhibitory control, a direction of the IED with more positive explicit attitudes than implicit attitudes was associated with higher MVPA. Our findings suggest that IED may be important factor in the physical activity behavior of older adults. Furthermore, a higher inhibitory control appears to override an impulsive negative response, enabling a more positive reflective assessment of physical activity to serve as the main driver of an active lifestyle.

Associations between elementary and middle school teachers\u2019 physical activity promoting practices and teacher- and school-level factors

BackgroundFew studies have evaluated teacher- and school-level characteristics associated with implementation of recommended physical activity (PA) promoting practices. The purpose of this study is to examine associations between teachers’ PA practices and: [1] teacher-level factors, including their own PA, and [2] school-level factors.MethodsThis cross-sectional study examined time spent daily in light PA (LPA) and moderate-vigorous PA (MVPA) in association with 7 teacher PA practices among 288 classroom/special area teachers and teaching assistants in 20 urban, suburban and rural schools (recruited through a school wellness trial) in 4 districts. LPA and MVPA was assessed using 24-h ankle accelerometry (up to seven consecutive days). A sum score for teacher PA practices was assessed via survey (7 items; sum score range: 7–35; Cronbach’s alpha = 0.73; higher scores indicate more PA promoting practices). Teacher-level factors included gender, race, self-reported height/weight, years teaching, and education. School-level factors included school type, free-and-reduced-price meal eligibility, student racial/ethnic composition, and urbanicity. Analyses included multilevel regression models, accounting for clustering within schools and adjusting for demographic covariates and school district.ResultsTeachers were 91% female, 63% elementary, 60% white, mean age 43.2 years (SD = 11.3), and 41% obese). Teachers wore accelerometers an average of 5.8 days, spent 399.6 min in LPA (SD = 85.0) per day, 24.1 min in MVPA (SD = 14.4) per day, and the mean teacher PA practices sum score was 22.4 (SD = 5.0). Every 15-min increase in MVPA was related to an increase in teacher PA practices sum score (coeff =1.07; SE = 0.28; p < 0.001). Female gender (versus males; coeff = − 1.95; SE = 0.92, p = 0.034), an obese weight status (versus non-obese; coeff = − 1.38; SE = 0.54, p = 0.010), and teaching in a middle school (versus elementary; coeff = − 3.86; SE = 0.54, p < 0.001) were associated with lower teacher PA practices scores. LPA was not associated with teacher PA promoting practices.ConclusionsTeachers with higher MVPA, but not higher LPA, and those without obesity were more likely to implement PA promoting practices that could positively impact their students’ PA. Similar to prior studies, these practices were more commonly implemented in elementary schools and by male teachers. Future studies in schools should explore whether improvement of teacher health behaviors subsequently impacts student health behaviors.Trial registrationClinical Trials, NCT03432715; Registered on 02/2/2018.

Infant motor development and physical activity and sedentary time at midlife.

This study investigated whether the timing of infant motor development is associated with self-reported and accelerometer-measured physical activity (PA) and sedentary time (ST) in midlife. This population-based study consisted of 4098 people born in 1966 in Northern Finland (NFBC 1966). Data on nine infant motor developmental milestones included making sounds, holding up the head, grabbing objects, turning from back to tummy, sitting without support, standing with support, walking with support, standing without support, and walking without support. At the age of 46, PA at leisure time and sitting time was self-reported. PA and ST were also measured with a wrist-worn Polar Active accelerometer that was instructed to be worn on the non-dominant hand 24h/d for 14days. A multiple linear regression analysis was used to analyze the association between infant motor development and PA and ST in midlife. Later infant motor development was weakly associated with higher accelerometer-measured light PA, but not with moderate-to-vigorous PA. Later infant locomotor development was associated with lower accelerometer-measured ST (β -0.07, p=0.012) and lower self-reported sitting time at work (β -0.06, p=0.004) in women. In conclusion, later infant motor development was associated with higher light PA and lower sedentary time at middle age. PA is a multifactorial behavior influenced by various factors from early childhood to midlife. Further research is required before more general conclusions can be drawn.

The relationship of sleep duration and quality to energy expenditure and physical activity in children.

Shorter sleep duration has been linked to the risk for obesity in children. The pathways linking sleep duration and quality to the risk of obesity are unclear, particularly the effect of sleep on energetics. We investigated the relationship between sleep duration, quality and timing in children, to the basal metabolic rate (BMR), total energy expenditure (TEE) and physical activity (PA). Fifty nine children in two age-groups (5-11 and 12-18 years) underwent evaluation of body composition (DXA), BMR in a room calorimeter, free-living TEE by doubly labelled water method, sleep and PA (7-day Actiheart monitor) during school break. Sleep duration contributed to the variance in BMR (β = 0.11, P = .009) after adjusting for age-group, sex, lean and fat mass, but not to the variance in TEE. Late sleep timing was related to lower PA. In the younger age-group, children who met recommended sleep duration on ≥50% of the 7 days had higher light PA (P = .03) and lower sedentary time (P = .009). Suboptimal sleep is associated with lower BMR, lower PA, and higher sedentary behaviours in young children. Prospective studies are needed to confirm if insufficient sleep duration or late sleep timing contribute to obesity risk by increasing sedentary behaviours and decreasing BMR.

Accelerometer-Measured Physical Activity Levels and Fatigue in Older Women.

The authors examined whether the associations between physical activity (PA) levels and fatigue vary by body mass index and physical performance, and whether substituting sedentary time (ST) with low light PA, high light PA, and moderate to vigorous PA (MVPA) was associated with better mean fatigue scores. In total, 6,111 participants (aged 65 years and older) were from the Women's Health Initiative Objective Physical Activity and Cardiovascular Health Study. PA levels were from a hip-worn GT3X accelerometer. Overall fatigue, energy, and weariness subdomains were from the RAND-36 Vitality subscale. Isotemporal substitution models examined the time-substitution effects. Interactions were observed between MVPA and short physical performance battery performance measure (p < .05). Substituting ST with 34.3 min of MVPA was associated on average with a 1.63-point improvement in fatigue score. Substituting ST with 50.2min of low light PA and 34.3 min of MVPA was associated on average with an energy score improvement of 1.18 and 2.06 points respectively. Substituting ST with 34.3 min of MVPA was associated on average with a 1.08-point improvement in weariness score (p < .05 for all).

Correlates of Light Physical Activity Among Cancer Survivors

Emerging evidence demonstrates positive health benefits of light physical activity (LPA) for cancer survivors. Yet, little research has explored modifiable factors that facilitate or hinder LPA behavior in this population. Furthermore, studies are often underpowered for conducting sub-group analyses. PURPOSE: To explore modifiable correlates of LPA among cancer survivors using a social cognitive framework, and how these correlates may differ among those engaging/not engaging in moderate-to-vigorous physical activity (MVPA). METHODS: Self-report data from the third survey of the American Cancer Society’s Studies of Cancer Survivors I (N = 1720) were analyzed. Social cognitive variables of interest reflect cognitive determinants (i.e. perceived health competence and perceived susceptibility to cancer recurrence) and environmental determinants (i.e. healthcare provider support, perceived social support, and unsupportive partner behaviors). The Leisure Time Exercise Questionnaire was used to create four LPA categories (0, 1-59, 60-119, and 120+ minutes/week). Ordinal regressions using forced entry were conducted, stratified by MVPA status (0 minutes of MVPA, ≥ 1 min MVPA). Models were adjusted for relevant covariates (i.e., demographic, cancer-related, health-related variables), missing data bias was examined, and sensitivity analyses were conducted to examine the robustness of the results. RESULTS: Among cancer survivors reporting no MVPA (n = 747), greater provider support for PA (adjusted OR [aOR] = 1.49, p = .03), greater perceived health competence (aOR = 1.44, p = .01), and greater unsupportive partner behaviors (aOR = 1.06, p = .03) were significantly correlated with higher LPA. No constructs were correlated with LPA among cancer survivors already engaging in MVPA (n = 973). Missing data bias was small (Cramer’s V/Phi < 0.1). Results were similar in unadjusted analyses, and when stratifying by insufficient and meeting MVPA recommendations. CONCLUSIONS: The utility of a social cognitive framework in explaining LPA among cancer survivors who do not engage in any MVPA was supported. Interventions may be more efficacious by incorporating healthcare provider support, improving health competence, and improving interpersonal skills that address unsupportive partners.

Sedentary Behavior Across Pregnancy, Gestational Age at Delivery, and Birthweight

PURPOSE: Lower gestational age at delivery (GAD) and large for gestational age birthweight (LGA) are indicators of poorer maternal-fetal health. While physical activity during pregnancy has been associated with greater GAD and lower risk of LGA, the effects of sedentary behavior (SB) on these outcomes are unknown. We aimed to describe patterns of SB across pregnancy and associations with GAD and risk for LGA METHODS: In this cohort study, SB (activPAL micro3) and physical activity (waist-worn ActiGraph GT3X-BT) were assessed in women for ≥ 4 days with > 10 hours, in each trimester of pregnancy. This preliminary analysis (59% recruited) includes women with available birth records and valid activity data for >1 trimester (n=56). Birthweight (BW) and GAD were abstracted from medical records. BW was categorized as LGA if > 90th percentile (n=18, 31%). Mean (SD) percent time spent sedentary was calculated in each trimester and differences across trimesters were tested using linear mixed models. The association of SB with continuous GAD and odds of LGA were estimated in separate regression models for each trimester. All beta coefficients were standardized (std β) per SD and adjusted for pre-pregnancy body mass index. If SB was associated with outcomes, further models estimated the effect of replacing SB with light physical activity (LPA) or moderate to vigorous physical activity (MVPA). RESULTS: Women spent a high percentage of time sedentary across trimesters: 1st (n=53) 64.0% (10.9); 2nd (n=50) 63.5% (9.5); and 3rd (n=47) 63.8% (10.4). SB did not differ across trimesters (p=0.792). Higher percent time spent sedentary in the first trimester was associated with lower GAD (std β=-0.45, p=0.038). Replacing first trimester SB with LPA (std β=0.48, p=0.037), but not MVPA (std β =-0.12, p=0.581), was associated with greater GAD. SB was not significantly associated with GAD in the 2nd (std β =-0.24, p=0.241) or 3rd (std β =-0.22, p=0.264) trimester. Odds of LGA was not significantly associated with SB in the 1st (OR=0.75, p=0.389), 2nd (OR=0.80, p=0.503), or 3rd (OR=1.03, p=0.932) trimester. CONCLUSIONS: Women in this study were highly and consistently sedentary across pregnancy. Higher LPA and lower SB during the first trimester may be advantageous for greater GAD, though risk for LGA offspring did not appear to be associated with SB.

Correlates of light physical activity among cancer survivors.

Emerging evidence demonstrates the positive health benefits of light physical activity (LPA) for cancer survivors. Yet, little research has explored modifiable factors that facilitate or hinder LPA behavior in this population. Correlates of LPA among cancer survivors were examined, and stratified by moderate-to-vigorous physical activity (MVPA) status. A cross-sectional analysis using the American Cancer Society's Studies of Cancer Survivors-I (N=1751) was conducted. Correlates of interest were health-care provider support for physical activity, perceived health competence, perceived social support, unsupportive partner behaviors, and perceived susceptibility to cancer recurrence. The primary outcome was self-reported LPA categorized at 0, 1-59, 60-119, and 120+minutes per week. Multivariable ordinal regressions using forced entry were conducted, stratified by MVPA status. Adjusted multivariable models revealed that, among those reporting no MVPA (n=757), greater provider support for physical activity (adjusted odds ratio [aOR]=1.51; 95% CI, 1.05-2.17; P=0.03), greater perceived health competence (aOR=1.44; 95% CI, 1.10-1.88; P=0.01), and greater unsupportive partner behaviors (aOR=1.06; 95% CI, 1.01-1.12; P=0.03) were significantly correlated with higher LPA. No social cognitive constructs were correlated with LPA among those already engaging in MVPA (n=994). LPA interventions targeting cancer survivors not engaging in any MVPA are warranted and may optimize limited intervention resources. Furthermore, interventions may be more efficacious by applying behavior change techniques that incorporate health-care provider support and improves health competence and positive interpersonal skills.