ORCID Profile
0000-0002-5754-7176
Current Organisations
Deakin University
,
The University of Manitoba
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Publisher: American Academy of Pediatrics (AAP)
Date: 04-2013
Abstract: To assess the effectiveness of a parent-focused intervention on infants’ obesity-risk behaviors and BMI. 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. 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. This intervention resulted in reductions in sweet snack consumption and television viewing in 20-month-old children.
Publisher: Springer Science and Business Media LLC
Date: 03-03-2017
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2012
Publisher: Springer Science and Business Media LLC
Date: 12-2017
Publisher: JMIR Publications Inc.
Date: 27-07-2017
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.YPMED.2015.07.019
Abstract: Sedentary behavior has negative health outcomes, evident even in young children. Identifying the prevalence of sedentary behavior in children <2years is important for determining the necessity for intervention strategies. The aim of this systematic review was to determine the prevalence of sedentary behavior in children <2years. Medline, PsycINFO, SPORTDiscus, and Education Research Complete electronic databases were searched, as were reference lists of included articles and the authors' own collections. Inclusion criteria were: published in a peer-reviewed English language journal mean age of children <2years and a reported measure of the prevalence of sedentary behavior. Twenty-four studies met the inclusion criteria. Most studies used parent-reported screen time as the sedentary behavior measure only one study reported time spent restrained (i.e., kept inactive) and no studies reported objectively assessed sedentary time. Estimates of young children's screen time ranged from 36.6 to 330.9min/day. The proportion of children meeting the zero screen time recommendation ranged from 2.3% to 83.0%. In conclusion, very little is known about sedentary behaviors other than screen time in this age group. Although highly variable, findings suggest that children are already engaging in high levels of screen time by age 2 and the majority exceed current recommendations.
Publisher: Springer Science and Business Media LLC
Date: 12-2019
DOI: 10.1186/S12966-019-0888-0
Abstract: 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. 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. The s le 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. 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.
Publisher: BMJ
Date: 06-10-2016
DOI: 10.1136/BJSPORTS-2016-096634
Abstract: To evaluate the effectiveness of behavioural interventions that report sedentary behaviour outcomes during early childhood. Systematic review and meta-analysis. Academic Search Complete, CINAHL Complete, Global Health, MEDLINE Complete, PsycINFO, SPORTDiscus with Full Text and EMBASE electronic databases were searched in March 2016. Inclusion 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. 31 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. Despite 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. CRD42015017090.
Publisher: Springer Science and Business Media LLC
Date: 25-05-2017
Publisher: Wiley
Date: 26-09-2019
DOI: 10.1111/OBR.12763
Abstract: 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. Systematic review, meta-analysis and realist synthesis. Embase and EBSCOhost (Academic Search Complete, CINAHL Complete, Global Health, MEDLINE Complete, PsycINFO, SPORTDiscus with full text), up to and including April 2017. 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. 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 < 0.001). The realist synthesis provided insights into the key contexts and mechanisms that appeared to be effective at changing children's PA. Based on a quantitative and qualitative examination of the evidence, this review provides specific recommendations for effective early childhood PA interventions for practitioners and policymakers.
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.JSAMS.2016.06.014
Abstract: Associations between maternal correlates and young children's physical activity levels across the whole day and the segmented day were examined. Cross-sectional study METHODS: 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. 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. 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.
Publisher: Human Kinetics
Date: 03-2016
Abstract: 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. 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). 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. 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.
Publisher: Elsevier BV
Date: 06-2012
Publisher: Oxford University Press (OUP)
Date: 19-03-2020
Abstract: 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.
Publisher: MDPI AG
Date: 18-01-2021
Abstract: A positive perception of motor skills is important for physical activity participation. The aim was to investigate which modifiable factors predict children’s perceived motor skills. Mothers completed questionnaires when their child was 3.5 and 5 years old. At 5 years old, the children’s perceived motor competence (PMC) was assessed. Separate linear regression models (up to 300 children) examined which factors at each time point predicted children’s PMC, adjusted for relevant confounders. Multivariate models were then run with factors associated (p 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.
Publisher: Oxford University Press (OUP)
Date: 11-05-2016
Publisher: Springer Science and Business Media LLC
Date: 14-05-2019
Publisher: Elsevier BV
Date: 10-2014
DOI: 10.1016/J.AMEPRE.2014.05.042
Abstract: 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. 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. 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. 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.
Publisher: Springer Science and Business Media LLC
Date: 28-06-2019
Publisher: Cold Spring Harbor Laboratory
Date: 06-08-2020
DOI: 10.1101/2020.08.04.20168542
Abstract: 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. To examine the relationship between endogenous testosterone concentration and lean mass and handgrip strength in healthy, pre-menopausal females. Secondary 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. Mean ± 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 ). These 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.
Publisher: ACER Press
Date: 10-2020
Publisher: Springer Science and Business Media LLC
Date: 15-05-2021
DOI: 10.1186/S12884-021-03847-W
Abstract: 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. in idual, 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. 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. Findings showed that postpartum women with depressive symptoms reported in idual (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 in idual (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. 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 in idual and social factors. Intervention strategies targeting predominantly in idual 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.
Publisher: Springer Science and Business Media LLC
Date: 10-06-2017
Publisher: Springer Science and Business Media LLC
Date: 11-2017
Publisher: Springer Science and Business Media LLC
Date: 30-05-2015
Publisher: Springer Science and Business Media LLC
Date: 28-05-2022
DOI: 10.1186/S12889-022-13493-2
Abstract: The neighbourhood social environment (NSE) has been associated with physical activity and screen time behaviours in adults and youth however less is known about this relationship in preschool-aged children (2–5 years). This study seeks to explore associations between the NSE and the physical activity and screen time behaviours of preschool-aged children. Cross-sectional data was collected in 2019. Parents (n = 214) of preschool-aged children ( m = 3.8 ± 0.8 years), from 187 different Australian postcodes representing all states and territories were invited to complete an online survey where they answered questions about their NSE (perceived social cohesion, social interaction, sense of community, social norms and neighbourhood crime) and proxy-reported their child’s usual physical activity and screen time (minutes/day). Two hierarchical linear regressions were run separately to assess relationships between NSE predictor variables and physical activity and screen time. Three logistic regressions were run to determine associations between NSE constructs and the likelihood of meeting: 1) physical activity (≥ 180 min/day including ≥ 60 min of moderate-to-vigorous-intensity), 2) screen time (≤ 60 min/day) and 3) both physical activity and screen time guidelines. Child age, gender, childcare attendance, and neighbourhood level socioeconomic status (SES) were controlled for in all analyses. Social interaction was associated with increased daily physical activity ( b = 17.76, 95%CI = 0.81, 34.71), decreased daily screen time ( b = -12.77, 95%CI = -23.23, -2.23) and improved the likelihood of meeting physical activity (OR = 1.81, 95%CI = 1.20, 2.75) and combined physical activity and screen time guidelines (OR = 1.51, 95%CI = 1.03, 2.21). Higher neighbourhood crime was associated with a lower likelihood of meeting screen time guidelines (OR = 0.47, 95%CI = 0.47, 0.99). Social cohesion, sense of community and social norms were not statistically significant predictors of daily physical activity, screen time or meeting guidelines. Social interaction showed the most consistent associations with physical activity and screen time. Future research should consider potential mediators of this relationship, including parental facilitation of children’s outdoor time. Improving understanding of the relationship between the NSE and physical activity and screen time in young children can help to guide community-based initiatives striving to optimise behavioural, health and social outcomes.
Publisher: American Chemical Society (ACS)
Date: 13-12-2020
Publisher: Springer Science and Business Media LLC
Date: 2013
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.JSAMS.2016.02.009
Abstract: 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. Cross-sectional study. 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 in idual 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. Fewer monitoring days were needed as the valid day criteria became more stringent. For ex le, at least 12h of wear time on at least 2 days was required to achieve a reliability of 0.7 for EE. In contrast, at least 8h/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. 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.
Publisher: Springer Science and Business Media LLC
Date: 29-03-2017
Publisher: MDPI AG
Date: 02-06-2021
Abstract: 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.
Publisher: JMIR Publications Inc.
Date: 09-02-2018
DOI: 10.2196/MHEALTH.8573
Publisher: Elsevier BV
Date: 11-2021
Publisher: Springer Science and Business Media LLC
Date: 13-05-2021
DOI: 10.1038/S41598-021-89232-1
Abstract: 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.
No related grants have been discovered for Jill Hnatiuk.