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The aim of this study was to examine the relationship between endogenous testosterone concentrations and lean mass and handgrip strength in healthy, pre-menopausal females. Testosterone has been positively associated with lean mass and strength in young and older males. Whether this relationship exists in pre-menopausal females is unknown. Secondary data from the 2013–2014 National Health and Nutrition Examination Survey were used to test this relationship. Females were aged 18–40 (n = 716, age 30 ± 6 years, mean ± SD) and pre-menopausal. Multivariate linear regression models were used to examine associations between total testosterone, lean mass index (LMI) and handgrip strength. Mean ± SD testosterone concentration was 1.0 ± 0.6 nmol L−1 and mean free androgen index (FAI) was 0.02 ± 0.02. In pre-menopausal females, testosterone was not associated with LMI (β = 0.05; 95%CI − 0.04, 0.15; p = 0.237) or handgrip strength (β = 0.01; 95%CI − 0.11, 0.12; p = 0.926) in a statistically significant manner. Conversely, FAI was associated with LMI (β = − 0.03; 95%CI − 0.05, − 0.02; p = 0.000) in a quadratic manner, meaning LMI increases with increasing FAI levels. Handgrip strength was not associated with FAI (β = 0.06; 95%CI − 0.02, 0.15; p = 0.137). These findings indicate that FAI, but not total testosterone, is associated with LMI in pre-menopausal females. Neither FAI nor total testosterone are associated with handgrip strength in pre-menopausal females when testosterone concentrations are not altered pharmacologically.

Background Postpartum women are at higher risk of depression compared to the general population. Despite the mental health benefits an active lifestyle can provide, postpartum women engage in low physical activity and high screen time. Very little research has investigated the social ecological (i.e. individual, social and physical environmental) influences on physical activity and screen time amongst postpartum women, particularly amongst those with depressive symptoms. Therefore, this study sought to examine the influences on physical activity and screen time amongst postpartum women with heightened depressive symptoms. Methods 20 mothers (3–9 months postpartum) participating in the Mums on the Move pilot randomised controlled trial who reported being insufficiently active and experiencing heightened depressive symptoms participated in semi-structured telephone interviews exploring their perceptions of the key influences on their physical activity and screen time across various levels of the social ecological model. Strategies for promoting physical activity and reducing screen time were explored with participants. Thematic analyses were undertaken to construct key themes from the qualitative data. Results Findings showed that postpartum women with depressive symptoms reported individual (i.e. sleep quality, being housebound, single income), social (i.e. childcare, social support from partner and friends) and physical environmental (i.e. weather, safety in the local neighbourhood) influences on physical activity. Postpartum women reported individual (i.e. screen use out of habit and addiction, enjoyment) and social (i.e. positive role modelling, social isolation) influences on screen-time, but no key themes targeting the physical environmental influences were identified for screen time. Strategies suggested by women to increase physical activity included mother’s physical activity groups, home-based physical activity programs and awareness-raising. Strategies to reduce screen time included the use of screen time tracker apps, increasing social connections and awareness-raising. Conclusions Amongst postpartum women with heightened depressive symptoms, influences on physical activity encompassed all constructs of the social ecological model. However, screen time was only perceived to be influenced by individual and social factors. Intervention strategies targeting predominantly individual and social factors may be particularly important for this high-risk group. These findings could assist in developing targeted physical activity and screen time interventions for this cohort.

Co-participation in physical activity may be important for helping families with young children meet physical activity recommendations. Yet, little is known about what families perceive to be the benefits, barriers and facilitators of co-participation. This study explored (i) parents’ perceptions about physical activity and possible benefits of family-based co-participation in physical activity, (ii) their perceived facilitators and barriers to co-participation and (iii) their recommendations for improving co-participation within their community. Fifteen parents (14 mothers, 1 father) of 2- to 4-year-old children residing in Western Sydney, Australia, participated in one-on-one interviews between September 2016 and January 2017. Interviews were audio-recorded and transcribed verbatim. Four main themes and seven sub-themes emerged from the thematic analysis of the interview data. When parents were asked to reflect on their understanding of physical activity, they discussed a range of well-known activities (e.g. active play, active transport) and also reported ‘anything but screen time’. The major benefits parents reported about co-participation were spending quality time together, improving children’s general health and well-being and the development of physical skills. Social (e.g. social networks, negative stereotypes) and environmental (e.g. home space, neighbourhood design, shading) facilitators and barriers were identified, yet their impact on co-participation often varied depending on the presence (or lack thereof) of other factors in the physical or social environment. Key recommendations suggested by parents included improvements to home outdoor spaces, neighbourhood design and play spaces and community services.

A positive perception of motor skills is important for physical activity participation. The aim was to investigate which modifiable factors predict children&rsquo, s perceived motor skills. Mothers completed questionnaires when their child was 3.5 and 5 years old. At 5 years old, the children&rsquo, s perceived motor competence (PMC) was assessed. Separate linear regression models (up to 300 children) examined which factors at each time point predicted children&rsquo, s PMC, adjusted for relevant confounders. Multivariate models were then run with factors associated (p &lt, 0.10) with perception. At 3.5 years, the time spent with same age and older children (both higher tertiles) and parental physical activity facilitation (sum of facilitation in last month, e.g., taking child to park) were initially associated with higher perception. Dance/gymnastics participation were associated with lower perceptions. Other child behaviours, maternal beliefs, play equipment, and swimming lessons were non-significant. In the final prospective model (n = 226), parental physical activity facilitation when child was 3.5 years old was the only factor to predict PMC. No factors were significant for the cross-sectional analyses at 5 years. Perceptions are formed based on past experiences which may explain why factors at 3.5 years rather than current experiences (when children were 5 years old) were associated with childhood perceptions.

Testosterone is a naturally occurring hormone that has been positively associated with lean mass and strength in males. Whether endogenous testosterone is related to lean mass and strength in females is unknown.ObjectiveTo examine the relationship between endogenous testosterone concentration and lean mass and handgrip strength in healthy, pre-menopausal females.MethodsSecondary data from the 2013-2014 National Health and Nutrition Examination Survey (NHANES)were used. Females were aged 18-40 (n=753, age 30 ± 6 yr, mean ± SD) and pre-menopausal. Multivariate linear regression models were used to examine associations between total testosterone, height-adjusted lean mass and handgrip strength.ResultsMean ± SD testosterone concentration was 1.0 ± 0.6 nmol·L-1 and mean free androgen index (FAI) was 0.02 ± 0.02. Mean fat-free mass index (FFMI) was 16.4 ± 3.0 kg·m-2 and mean handgrip strength was 61.7 ± 10.5 kg. In females, testosterone was not associated with FFMI (β=0.08; 95%CI: −0.02, 0.18; p=0.11) or handgrip strength (β=0.03; 95%CI: −0.11, 0.17; p=0.67) in a statistically significant manner. Conversely, FAI was positively associated with FFMI (β=0.17; 95%CI: 0.01, 0.33; p=0.04) but not handgrip strength (β=0.19; 95%CI: −0.02, 0.21; p=0.10).ConclusionsThese findings indicate that FAI, but not total testosterone, is associated with FFMI in females. The small coefficients however suggest that FAI only accounts for a minor proportion of the variance in FFMI, highlighting the complexity of the regulation of lean mass in female physiology. FAI nor total testosterone are associated with handgrip strength in females when testosterone concentrations are not altered pharmacologically.

OBJECTIVE: The objective of the study is to evaluate the effectiveness of interventions to increase physical activity (PA) in 0-5 year olds and to determine what works, for whom, in what circumstances. DESIGN: Systematic review, meta-analysis and realist synthesis. DATA SOURCES: Embase and EBSCOhost (Academic Search Complete, CINAHL Complete, Global Health, MEDLINE Complete, PsycINFO, SPORTDiscus with full text), up to and including April 2017. ELIGIBILITY CRITERIA: Published in a peer-reviewed English language journal; randomized or controlled trial design; aimed to increase children's PA levels; reported on objectively assessed PA in children between 0 and 5.9 years at baseline and post-intervention. RESULTS: Thirty-four studies were included in the review, mostly conducted in the preschool/childcare setting. Meta-analyses showed an overall non-significant (Z = 0.04, p = 0.97) mean difference of 0.03 (95% CI = -1.57, 1.63) minutes/day for light-intensity PA (n = 11). The overall mean difference for moderate-intensity to vigorous-intensity PA (n = 21) was 2.88 (95% CI = 1.54, 4.23) minutes/day, indicating a small but significant overall positive effect (Z = 4.20, p

Background Fundamental motor skills (FMS) are important for physical activity and healthy weight status in children, yet it is unclear which early childhood factors facilitate subsequent motor skill. The aim of this prospective study was to investigate which modifiable family and home environment factors in the early years predict children’s FMS at age five. Methods Mothers from the Melbourne InFANT program (registered with the International Standard Randomised Controlled Trial Number Register (ISRCTN81847050)) completed questionnaires when child was aged 4, 9, 19 months old, and 3.5 years old on factors hypothesised to predict motor skills. Some factors were grouped in tertiles (high, medium, low) due to the nature of the distribution. At 5 years old children were assessed on 6 locomotor and 6 object control skills (Test of Gross Motor Development-2). Eight regression models examined the association between factors at each time-point and children’s skills (object control and locomotor) at 5 years old. Results The sample varied by time-point (178 to 259 children). Maternal physical activity optimism (4 months; β = 2.43), home physical activity equipment (9 months; β = 0.82), time outdoors – middle (9 months; β = 2.50) and highest tertile (9 months; β = 2.86), time free to move about - highest tertile (19 months; β = 2.41), time with older children - middle (19 months; β = 3.15) and highest tertile (3.5 years; β = 3.00) were predictive of better locomotor scores. Mothers’ own physical activity (9 months; β = − 0.01) and time active with mum – highest tertile (3.5 years; β = − 3.73) were negatively associated with locomotor skill. Time with older children - highest (4 months; β = 2.27) and middle tertile (19 months; β = 2.97), time free to move about – middle (19 months; β = 2.55) and highest tertile (19 months; β = 2.47), and more home equipment (9 months; β = 0.83); (3.5 years; β = 0.17) were predictive of better object control skills. Maternal physical activity knowledge (3.5 years; β = − 3.05) was negatively associated with object control skill. Conclusions Providing a supportive environment with older children and equipment, and allowing toddlers’ freedom to move, appears important. Opportunities exist to educate parents on their important role in developing children’s motor skills. Clinicians could advise parents that the home environment can make a difference to their child’s FMS starting from infancy.

Background: Understanding the mechanisms (mediators) of behavior change is crucial to designing more effective interventions. However, this is rarely reported. This paper investigates the mechanisms that explain the lack of intervention effect on physical activity and the significant effect on television viewing time from an early childhood trial. Methods: Secondary analyses were undertaken of data from a cluster randomized controlled trial. The Melbourne Infant Feeding, Activity and Nutrition Trial (INFANT) was a 15-month group program promoting obesity-protective behaviors from the age of 4 months. Outcomes relevant to the current study were child physical activity (accelerometer), television viewing time (maternal report) and 12 potential mediator scales (maternal report). Linear regression models used the product of coefficients method with a joint significance test. Results: Complete data were from 398 mother-child dyads. Despite weak evidence of an intervention effect on the mother’s physical activity knowledge and optimism, there was no effect on children’s physical activity, and no clear mechanisms were identified. An intervention effect was observed for the mothers’ television knowledge (unstandardized regression coefficient for a path (a) = 0.34, 95% confidence interval (CI95) = 0.22, 0.45), with weak evidence for maternal efficacy (a = 0.11, CI95 = −0.02, 0.24) and the use of television (a = −0.10, CI95 = −0.22, 0.01). The intervention impact on television knowledge explained 75% of the difference between the intervention and control groups in children’s television viewing. Conclusions: In the very early childhood period, as mothers are commencing their parenting journey, improving their behavioral knowledge appears to be the biggest contributor to reducing child television viewing, constituting a relatively simple strategy that could be implemented across clinical and public health settings. In contrast, it remains unclear what mechanisms may increase physical activity levels in this age group.

Objectives: To identify the number of hours and days or nights of monitoring required to reliably estimate energy expenditure (EE), steps, waking sedentary time, light- (LPA), moderate- (MPA), vigorous- (VPA), moderate- to vigorous-intensity physical activity (MVPA), time in bed and total sleep time using the SenseWear Armband.Design: Cross-sectional study.Methods: One hundred and two children (50% boys) aged 8-11 years from six schools wore a SenseWear Armband (BodyMedia Inc, USA) for eight consecutive days (seven consecutive nights). Hourly increments of valid day wear time criteria were examined (days/week; 8h/day-14h/day). Intra-class correlation coefficients estimated the reliability for any individual day for each wear time criteria. The Spearman-Brown prophecy formula was used to determine the number of days/nights of monitoring needed to achieve reliability estimates of 0.7, 0.8 and 0.9.Results: Fewer monitoring days were needed as the valid day criteria became more stringent. For example, at least 12 h of wear time on at least 2 days was required to achieve a reliability of 0.7 for EE. In contrast, at least 8 h/day on 5 days resulted in reliable estimates (0.7) for MPA, VPA and MVPA. Between 6 and 7 nights of monitoring were required to reliably estimate children's time in bed and total sleep time, respectively.Conclusions: A 7-day monitoring protocol in primary school-aged children would provide acceptable reliability for the assessment of EE, waking sedentary time, LPA, MPA, VPA, MVPA, time in bed and total sleep time, as assessed by the SenseWear Armband. (C) 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved. usc Refereed/Peer-reviewed

Objective Fathers’ parenting behaviours contribute to the development of children’s dietary behaviours and subsequent weight outcomes, yet the majority of research focusses on maternal influences. Understanding fathers’ perceptions of their effectiveness to influence children’s dietary behaviours will allow the development of whole-of-family interventions promoting obesity protective behaviours. This unique study is the first to investigate 1) tracking of paternal self-efficacy for promoting obesity protective dietary intakes in young children; 2) demographic characteristics of fathers and their self-efficacy category; and 3) associations between paternal self-efficacy and young children’s dietary intakes. Methods Paternal self-efficacy for promoting children’s obesity protective dietary intakes was assessed longitudinally from fathers (n = 195) in the Extended Infant Feeding Activity and Nutrition Trial Program at child age 4 and 36 months. Multinomial logistic regression examined self-efficacy tracking categories (persistently high; persistently low; increasing; decreasing) by paternal age, education and BMI. Linear regression examined associations between paternal self-efficacy tracking categories and child dietary intakes at 36 months. Results Paternal self-efficacy for promoting children’s obesity protective dietary intakes reduced over time. Fathers with trade/certificate or university qualifications had lower odds of having persistently low/decreasing self-efficacy (97 and 87% lower respectively) compared to high-school educated fathers. Positive associations (β (95% CI)) were observed between paternal self-efficacy category and children’s dietary intakes at 36 months: increasing self-efficacy and fruit (β89.8 (6.8; 172.7)), and vegetables (β39.2 (12.2; 66.2)); persistently high self-efficacy and water (β69.1 (2.9; 135.1)); decreasing self-efficacy and non-core drinks ((β30.1 (10.1; 50.1)). Persistently high self-efficacy was negatively associated with non-core drinks (β-20.2 (− 34.8; − 5.5)), with negative associations observed between decreasing self-efficacy and children’s intakes of fruit (β − 49.9 (− 87.5; − 12.3)), vegetables (β-19.9 (− 31.7; − 8.2)) and water (β-92.4 (− 172.6; − 12.3)). Conclusions Higher and/or sustained paternal self-efficacy is associated with fathers’ education and is important in promoting children’s obesity protective dietary intakes. Associations between paternal self-efficacy and children’s dietary intakes are present at a young age. This investigation was unique in its focus on paternal self-efficacy for promoting children’s obesity protective dietary intakes and associations with children’s dietary intakes. Future family interventions should consider how to maintain and/or improve paternal self-efficacy to promote obesity protective intakes from early childhood.

Background: Understanding changes in physical activity and sedentary time (SED) during early childhood may provide insights into how to effectively promote a healthy start to life. This study examined changes in total volume and bouts of SED, light- (LPA), and moderate- to vigorous-intensity physical activity (MVPA) across early childhood, and explored differences in change between boys and girls. Methods: Data were drawn from 330 children participating in the Melbourne InFANT Program, collected between 2008 and 2013 and analysed in 2017. Children’s physical activity and SED were assessed for at least 7 days at each timepoint using ActiGraph GT1M accelerometers at 19 months, 3.5 and 5 years of age. Total volume of SED (≤100 counts per minute [CPM]), LPA (101–1680 CPM) and MVPA (≥1681 CPM) were expressed as a percentage of wear time, and the frequency (number of bouts/day) and duration (mins/bout) of SED, LPA and MVPA bouts ≥1 min were calculated at each time point. Multilevel models with random intercepts and slopes were used to examine changes in total volume and bouts of SED, LPA and MVPA for boys and girls. Results: Compared to aged 19 months, children’s total volume of SED and LPA decreased at 3.5 and 5 years old, while MVPA increased. The frequency of SED bouts at 3.5 and 5 years was greater than at 19 months, but the duration was shorter. Additionally, the frequency and duration of LPA bouts was lower and MVPA bout frequency and duration was greater at 3.5 and 5 years. In general, there was no evidence of sex differences in trajectories of children’s physical activity and SED. However, variations in trajectory were observed at the individual child level. Conclusions: Children’s total volume and bouts of SED, LPA and MVPA change across early childhood, mostly in a favourable direction. Trajectories appear to be similar for boys and girls. Investigation of individual variation in trajectories is likely to provide greater insight into associations between physical activity and future health and behavioural outcomes. Refereed/Peer-reviewed

Background:Parental modeling has been shown to be important for school-aged children’s physical activity (PA) and television (TV) viewing, yet little is known about its impact for younger children. This study examined cross-sectional and 3-year longitudinal associations between PA and TV viewing behaviors of parents and their preschool children.Methods:In 2008–2009 (T1), parents in the Healthy Active Preschool and Primary Years (HAPPY) cohort study (n = 450) in Melbourne, Australia, self-reported their weekly PA and TV viewing and proxy-reported their partner’s PA and TV viewing and their 3- to 5-year-old preschool child’s TV viewing. Children’s PA was assessed via accelerometers. Repeat data collection occurred in 2011–2012 (T2).Results:Mothers’ and fathers’ PAs were associated with PA among preschool girls at T1, but not boys. Parents’ TV viewing times were significant correlates of girls’ and boys’ TV viewing at T1. Longitudinally, mothers’ PA at baseline predicted boys’ PA at T2, whereas sex-specific associations were found for TV viewing, with mothers’ and fathers’ TV viewing at T1 associated with girls’ and boys’ TV viewing respectively at T2.Conclusions:The PA and TV viewing of both parents are significantly associated with these behaviors in preschool children. The influence of the sex-matched parent appears to be important longitudinally for children’s TV viewing.

Background Physical activity is considered to have health benefits across the lifespan but levels, patterns, and correlates have not been well described in infants and toddlers under the age of two years. Methods This study aimed to describe objectively and subjectively measured physical activity in a group of South African infants aged 3- to 24-months (n = 140), and to investigate individual and maternal correlates of physical activity in this sample. Infants’ physical activity was measured using an Axivity AX3 wrist-worn accelerometer for one week and the mean vector magnitude was calculated. In addition, mothers reported the average amount of time their infant spent in various types of activities (including in front of the TV), their beliefs about infants’ physical activity, access to equipment in the home environment, and ages of motor development milestone attainment. Analysis of variance (ANOVA) and pair-wise correlations were used to test age and sex differences and associations with potential correlates. Results There were significant age and sex effects on the distribution of time spent at different physical activity intensities (Wilks’ lambda = 0.06, p

BackgroundDespite public health guidelines to limit sedentary behavior, many young children spend large amounts of time sedentary (eg, screen and sitting time) during waking hours. ObjectiveThe objective of this study was to test the feasibility and efficacy of a parent-focused, predominantly text message–delivered intervention to support parents to reduce the amount of time their children spend in sedentary behavior. MethodsMini Movers was a pilot randomized controlled trial delivered to parents of 2- to 4-year-old children in Melbourne, Australia. Participants were recruited through playgroups, social media, and snowball sampling. Eligibility criteria were having an ambulatory child (2-4 years), English literacy, and smartphone ownership. Participants were randomized to intervention or wait-list control on a 1:1 ratio after baseline data collection. The 6-week intervention was predominantly delivered via text messages, using a Web-based bulk text message platform managed by the interventionist. Intervention strategies focused on increasing parental knowledge, building self-efficacy, setting goals, and providing reinforcement, and were underpinned by the Coventry, Aberdeen & London-Refined taxonomy of behavior change techniques and social cognitive theory. The primary outcome was intervention feasibility, measured by recruitment, retention, intervention delivery, and fidelity; process evaluation questionnaires; and qualitative interviews with a subsample of participants. Secondary outcomes were children’s screen and restraint time (parent report), sitting time (parent report, activPAL), and potential mediators (parent report). Linear regression models were used to determine intervention effects on secondary outcomes, controlling for the child’s sex and age and clustering by playgroup; effect sizes (Cohen's d) were calculated. ResultsA total of 57 participants (30 intervention; 27 wait-list control) were recruited, and retention was high (93%). Process evaluation results showed that the intervention was highly acceptable to parents. The majority of intervention components were reported to be useful and relevant. Compared with children in the control group, children in the intervention group had significantly less screen time postintervention (adjusted difference [95% CI]=−35.0 [−64.1 to −5.9] min/day; Cohen's d=0.82). All other measures of sedentary behavior were in the expected direction, with small to moderate effect sizes. ConclusionsMini Movers was shown to be a feasible, acceptable, and efficacious pilot intervention for parents of young children, warranting a larger-scale randomized control trial. Trial RegistrationAustralian New Zealand Clinical Trials registry: ACTRN12616000628448; https://www.anzctr.org.au/ Trial/Registration/TrialReview.aspx?ACTRN=12616000628448p (Archived by WebCite at http://www.webcitation.org/ 6wZcA3cYM)

Background Preschool children can spend up to 12 h a day in sedentary time and few meet current recommendations for screen time. Little is known about ecological correlates that could be targeted to decrease specific versus total sedentary behaviour. This study examined whether the correlates of screen time and sedentary time differ in preschool boys and girls. Methods Parents participating in the HAPPY Study in 2008/09 in Melbourne, Australia reported their child’s usual screen time and potential individual, social and physical environment correlates. Children wore ActiGraph GT1M accelerometers for eight days to objectively assess sedentary time (

Background Preschool children can spend up to 12 h a day in sedentary time and few meet current recommendations for screen time. Little is known about ecological correlates that could be targeted to decrease specific versus total sedentary behaviour. This study examined whether the correlates of screen time and sedentary time differ in preschool boys and girls. Methods Parents participating in the HAPPY Study in 2008/09 in Melbourne, Australia reported their child’s usual screen time and potential individual, social and physical environment correlates. Children wore ActiGraph GT1M accelerometers for eight days to objectively assess sedentary time (

Objectives: Associations between maternal correlates and young children's physical activity levels across the whole day and the segmented day were examined.Design: Cross-sectional studyMethods: Participants were 136 mothers and their 1-3 year old children recruited between July 2013 and March 2014. Mothers reported time spent providing physical activity opportunities for their child, co-participating in and modelling physical activity and sedentary behaviours during the morning, afternoon and evening. Participants wore ActiGraph GT3X (mothers) and GT3X+ (children) accelerometers concurrently for seven consecutive days and the time spent in light- (LPA), moderate- to vigorous- (MVPA) and total (LMVPA) physical activity were assessed. Two-level (family; recruitment group) multivariate models examined associations between maternal correlates (including maternal objectively-assessed sedentary time [ST] and physical activity) and children's physical activity.Results: Maternal self-reported co-participation in sedentary behaviour and provision of child opportunities for physical activity were associated with children's physical activity; associations varied by period and physical activity intensity. During the morning period, mothers' objectively assessed ST was negatively associated with children's MVPA and LMVPA while her LPA was positively associated with children's LPA, MVPA and LMVPA. Mothers' MVPA was negatively associated with children's LPA and LMVPA during the evening period.Conclusions: Maternal correlates of young children's-physical activity may be period-and intensity specific. Programmes promoting physical activity for families may need to consider incorporating strategies to reduce mother-child co-participation in sedentary behaviour, increase mothers' provision of opportunities to be active and increase mothers' own LPA over ST during certain periods of the day. (C) 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved. Refereed/Peer-reviewed

Context: Identifying current physical activity levels and sedentary time of preschool children is important for informing government policy and community initiatives. This paper reviewed studies reporting on physical activity and time spent sedentary among preschool-aged children (2-5 years) using objective measures. Evidence acquisition: Databases were searched for studies published up to and including April 2013 that reported on, or enabled the calculation of, the proportion of time preschool children spent sedentary and in light- and moderate to vigorous-intensity physical activity. A total of 40 publications met the inclusion criteria for physical activity and 31 met the inclusion criteria for sedentary time. Objective measures included ActiGraph, Actiwatch, Actical, Actiheart, and RT3 accelerometers, direct observation, and Quantum XL telemetry heart rate monitoring. Data were analyzed in May 2013. Evidence synthesis: Considerable variation in prevalence estimates existed. The proportion of time children spent sedentary ranged from 34% to 94%. The time spent in light-intensity physical activity and moderate to vigorous-intensity physical activity ranged from 4% to 33% and 2% to 41%, respectively. Conclusions: The considerable variation of prevalence estimates makes it difficult to determine the "true" prevalence of physical activity and sedentary time in preschool children. Future research should aim to reduce inconsistencies in the employed methodologies to better understand preschoolers' physical activity levels and sedentary behavior.

OBJECTIVE: To assess the effectiveness of a parent-focused intervention on infants’ obesity-risk behaviors and BMI. METHODS: This cluster randomized controlled trial recruited 542 parents and their infants (mean age 3.8 months at baseline) from 62 first-time parent groups. Parents were offered six 2-hour dietitian-delivered sessions over 15 months focusing on parental knowledge, skills, and social support around infant feeding, diet, physical activity, and television viewing. Control group parents received 6 newsletters on nonobesity-focused themes; all parents received usual care from child health nurses. The primary outcomes of interest were child diet (3 × 24-hour diet recalls), child physical activity (accelerometry), and child TV viewing (parent report). Secondary outcomes included BMI z-scores (measured). Data were collected when children were 4, 9, and 20 months of age. RESULTS: Unadjusted analyses showed that, compared with controls, intervention group children consumed fewer grams of noncore drinks (mean difference = –4.45; 95% confidence interval [CI]: –7.92 to –0.99; P = .01) and were less likely to consume any noncore drinks (odds ratio = 0.48; 95% CI: 0.24 to 0.95; P = .034) midintervention (mean age 9 months). At intervention conclusion (mean age 19.8 months), intervention group children consumed fewer grams of sweet snacks (mean difference = –3.69; 95% CI: –6.41 to –0.96; P = .008) and viewed fewer daily minutes of television (mean difference = –15.97: 95% CI: –25.97 to –5.96; P = .002). There was little statistical evidence of differences in fruit, vegetable, savory snack, or water consumption or in BMI z-scores or physical activity. CONCLUSIONS: This intervention resulted in reductions in sweet snack consumption and television viewing in 20-month-old children.

Aim or objectiveTo evaluate the effectiveness of behavioural interventions that report sedentary behaviour outcomes during early childhood.DesignSystematic review and meta-analysis.Data sourcesAcademic Search Complete, CINAHL Complete, Global Health, MEDLINE Complete, PsycINFO, SPORTDiscus with Full Text and EMBASE electronic databases were searched in March 2016.Eligibility criteria for selecting studiesInclusion criteria were: (1) published in a peer-reviewed English language journal; (2) sedentary behaviour outcomes reported; (3) randomised controlled trial (RCT) study design; and (4) participants were children with a mean age of ≤5.9 years and not yet attending primary/elementary school at postintervention.Results31 studies were included in the systematic review and 17 studies in the meta-analysis. The overall mean difference in screen time outcomes between groups was −17.12 (95% CI −28.82 to −5.42) min/day with a significant overall intervention effect (Z=2.87, p=0.004). The overall mean difference in sedentary time between groups was −18.91 (95% CI −33.31 to −4.51) min/day with a significant overall intervention effect (Z=2.57, p=0.01). Subgroup analyses suggest that for screen time, interventions of ≥6 months duration and those conducted in a community-based setting are most effective. For sedentary time, interventions targeting physical activity (and reporting changes in sedentary time) are more effective than those directly targeting sedentary time.Summary/conclusionsDespite heterogeneity in study methods and results, overall interventions to reduce sedentary behaviour in early childhood show significant reductions, suggesting that this may be an opportune time to intervene.Trial registration numberCRD42015017090.

Background Co-participation in physical activity may be a useful strategy for increasing physical activity in mothers and their young children, yet little empirical evidence exists on this topic for young families. This study aimed to identify the prevalence of mother-child co-participation in physical activity and examine the association between co-participatory behaviours and objectively-assessed physical activity in young children and their mothers. Methods One-hundred twenty-three 4–6 year-old children and their mothers were recruited from preschools in Belgium between November 2010 and January 2011. Mothers completed a questionnaire assessing the frequency of co-participation in five activities. Both mothers and children wore ActiGraph GT1M accelerometers concurrently for 7 days to assess the time spent in moderate-to vigorous-intensity physical activity (MVPA) and light- to vigorous-intensity physical activity (LMVPA). Descriptive statistics (means, frequencies) were used to determine the prevalence of co-participation. Separate multiple linear regression analyses examined the association between co-participation and mothers’ and children’s physical activity on weekdays and weekends. Results Most mothers reported infrequent co-participation in physical activities with their children. On weekdays, walking or cycling for short trips was positively associated with children’s MVPA while attending a park or similar more than once per week was negatively associated with children’s MVPA and LMVPA. Going to an indoor play centre together once or more per week was negatively associated with mother’s LMVPA. On weekends, walking or cycling with their child in their free time was positively associated with both children’s and mothers’ MVPA and childrens’ LMVPA. Going to an indoor play centre together 1–3 times/month was negatively associated with children’s weekend MVPA. Conclusions Reported rates of co-participation in mothers and their preschool children were low. The association with maternal and child physical activity may be dependent on the co-participatory behaviour assessed and may differ between weekday and weekends. Promoting walking and cycling together during leisure time may be an effective strategy to increase both preschool children’s and mothers’ MVPA.

Introduction There is limited evidence around the physical activity support delivered by different types of healthcare providers (HCPs) to patients with type 2 diabetes mellitus. The primary purpose of this study was to determine the type of physical activity support delivered by 3 HCP types, and to compare this support to that perceived by patients with type 2 diabetes. A secondary aim was to describe awareness, knowledge and use of the Canadian Diabetes Association (CDA) physical activity guidelines and Canada's Physical Activity Guide (CPAG). Method The HCP and the Patient Physical Activity Support Questionnaire were answered by 48 HCPs and 26 patients from 8 interprofessional primary care clinics specializing in diabetes education. Results There was no difference in the type of physical activity support between HCP types, however, there was a difference between overall HCP and patient report of physical activity support (5.29 vs. 2.04 unprompted; 9.90 vs. 6.07 prompted, p Conclusion Physical activity support is similar between all HCP types in interprofessional primary care settings, but this support is perceived differently by patients. Strategies to increase certain types of physical activity support would allow for optimal counselling in primary care.

Background: Mothers' self-efficacy for limiting their children's television viewing is an important correlate of this behaviour in young children. However, no studies have examined how maternal self-efficacy changes over time, which is potentially important during periods of rapid child development. This study examined tracking of maternal self-efficacy for limiting young children's television viewing over 15-months and associations with children's television viewing time.Methods: In 2008 and 2010, mothers (n = 404) from the Melbourne InFANT Program self-reported their self-efficacy for limiting their child's television viewing at 4- and 19-months of age. Tertiles of self-efficacy were created at each time and categorised into: persistently high, persistently low, increasing or decreasing self-efficacy. Weighted kappa and multinomial logistic regression examined tracking and demographic and behavioural predictors of change in self-efficacy. A linear regression model examined associations between tracking categories and children's television viewing time.Results: Tracking of maternal self-efficacy for limiting children's television viewing was low (kappa = 0.23, p < 0.001). Mothers who had persistently high or increasing self-efficacy had children with lower television viewing time at 19-months (beta = -35.5; 95 % CI = -54.4,-16.6 and beta = 37.0; 95 % CI = -54.4, -19.7, respectively). Mothers of children with difficult temperaments were less likely to have persistently high self-efficacy. Mothers who met adult physical activity guidelines had 2.5 greater odds of increasing self-efficacy.Conclusions: Interventions to increase and maintain maternal self-efficacy for limiting children's television viewing time may result in lower rates of this behaviour amongst toddlers. Maternal and child characteristics may need to be considered when tailoring interventions. Refereed/Peer-reviewed

Background Young children are at risk of not meeting physical activity recommendations. Identifying factors from the first year of life which influence toddlers’ physical activity levels may help to develop targeted intervention strategies. The purpose of this study was to examine early childhood predictors of toddlers’ physical activity across the domains of maternal beliefs and behaviours, infant behaviours and the home environment. Methods Data from 206 toddlers (53% male) participating in the Melbourne InFANT Program were collected in 2008–2010 and analysed in 2012. Mothers completed a survey of physical activity predictors when their child was 4- (T1) and 9- months old (T2). Physical activity was assessed by ActiGraph GT1M accelerometers at 19- months (T3) of age. Results One infant behaviour at T1 and one maternal belief and two infant behaviours at T2 showed associations with physical activity at T3 and were included in multivariate analyses. After adjusting for the age at which the child started walking and maternal education, the time spent with babies of a similar age at 4-months (β = 0.06, 95% CI [0.02, 0.10]) and the time spent being physically active with their mother at 9-months (β = 0.06, 95% CI [0.01, 0.12]) predicted children’s physical activity at 19-months of age. Conclusions Promotion of peer-interactions and maternal-child co-participation in physical activity could serve as a health promotion strategy to increase physical activity in young children. Future research is required to identify other early life predictors not assessed in this study and to examine whether these factors predict physical activity in later life stages.

AB Purpose: It is a commonly held perception that most young children are naturally active and meet physical activity recommendations. However, there is no scientific evidence available on which to confirm or refute such perceptions. The purpose of this study was to describe the physical activity levels and patterns of Australian toddlers. Methods: Physical activity and demographic data of two hundred ninety-five 19-month-old children from the Melbourne InFANT Program were measured using accelerometers and parent surveys. Validated cut points of 192-1672 and >1672 counts per minute were used to determine time spent in light- (LPA) and moderate-to-vigorous- (MVPA) intensity physical activity, respectively. To be included in the analysis, children were required to have four valid days of accelerometer data to provide an acceptable (>0.70) reliability estimate of LPA and MVPA. Physical activity data for different periods of the day were examined. Results: On average, toddlers engaged in 184 min of LPA and 47 min of MVPA daily, and 90.5% met the current Australian physical activity recommendations for 0- to 5-yr-olds (180 min of LPA/MVPA per day). Physical activity levels during mid morning and mid afternoon were higher than those during other periods. Physical activity patterns for boys and girls were similar, although boys engaged in more physical activity during the morning hours than girls did. Conclusions: Most children meet the physical activity recommendations, although the majority of activity undertaken in the study was of light intensity. Boys were more active than girls were in the morning hours, but there were no differences between sexes over the entire day. Certain periods of the day may hold more promise for intervention implementation than others do. (C)2012The American College of Sports Medicine

AB Purpose: It is a commonly held perception that most young children are naturally active and meet physical activity recommendations. However, there is no scientific evidence available on which to confirm or refute such perceptions. The purpose of this study was to describe the physical activity levels and patterns of Australian toddlers. Methods: Physical activity and demographic data of two hundred ninety-five 19-month-old children from the Melbourne InFANT Program were measured using accelerometers and parent surveys. Validated cut points of 192-1672 and >1672 counts per minute were used to determine time spent in light- (LPA) and moderate-to-vigorous- (MVPA) intensity physical activity, respectively. To be included in the analysis, children were required to have four valid days of accelerometer data to provide an acceptable (>0.70) reliability estimate of LPA and MVPA. Physical activity data for different periods of the day were examined. Results: On average, toddlers engaged in 184 min of LPA and 47 min of MVPA daily, and 90.5% met the current Australian physical activity recommendations for 0- to 5-yr-olds (180 min of LPA/MVPA per day). Physical activity levels during mid morning and mid afternoon were higher than those during other periods. Physical activity patterns for boys and girls were similar, although boys engaged in more physical activity during the morning hours than girls did. Conclusions: Most children meet the physical activity recommendations, although the majority of activity undertaken in the study was of light intensity. Boys were more active than girls were in the morning hours, but there were no differences between sexes over the entire day. Certain periods of the day may hold more promise for intervention implementation than others do. (C)2012The American College of Sports Medicine

colonic tissue mRNA libraries and validated an in vitro human enteroendocrine I-cell model (Hutu80) using a variety of known TAS2R bitter agonists. We show that mRNAs for bitter taste receptors are expressed in human gastric, small intestinal and colonic tissue as well as the Hutu-80 cellline. In addition, Hutu-80 cells respond to a subset of known bitter agonists via a G-protein coupled phospholipase C mediated pathway, elevated cytoplasmic calcium concentrations and subsequent release of CCK. In conclusion, the capability to sense luminal bitter compounds may occur throughout the GI tract. However, not all known lingual bitter agonists stimulate hormone secretion in Hutu-80 cells, suggesting key differences between lingual and GI bitter sensing that may have important implications for design of functional foods to modulate appetite through bitter sensing.

Background Sedentary behaviour (e.g. television viewing, sitting time) tracks over time and is associated with adverse health and developmental outcomes across the lifespan. Young children (5 years or younger) spend up to 12 h/day sedentary, of which around 2 h is spent in screen time (e.g. watching television). Interventions to reduce sedentary behaviour in early childhood report mixed results and many have limited potential for scalability. Mobile phones offer a wide-reaching, low-cost avenue for the delivery of health behaviour programmes to parents but their potential to reduce young children’s sedentary behaviour has not been widely tested. This study aims to test the feasibility and efficacy of a parent-focused, predominantly mobile telephone-delivered intervention to support parents to minimise the amount of time their child spends using screens and in overall sitting time. Methods/design Mini Movers is a pilot randomised controlled trial recruiting 100 parents and children. Inclusion criteria include having a child aged between 2 and 4 years, being able to speak, read and write English, and smartphone ownership. Participants will be randomised to the intervention or a wait-list control group at a 1:1 ratio. Intervention group parents will receive printed materials including a content booklet and goal-checking magnet and will participate in a one-on-one discussion with the interventionist to plan two goals to reduce their child’s sedentary behaviour. Subsequently, the intervention will be delivered over 6 weeks via personalised and interactive text messages promoting positive health behaviours (strategies for decreasing screen time and overall sitting time), goal setting and self-monitoring. Outcomes to be assessed include intervention feasibility and children’s screen time and objectively-assessed sitting time. Discussion Few studies have used mobile phone technology to deliver health behaviour programmes to parents of young children. Findings will inform the development of larger-scale interventions to reduce sedentary behaviour during early childhood. Trial registration Australian New Zealand Clinical Trials registry, identifier: ACTRN12616000628448. Prospectively registered on 16 May 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1841-7) contains supplementary material, which is available to authorized users.