Associations between levels of physical literacy and adherence to the 24-h movement guidelines among university students: A cross-sectional study.

Objectives: Emerging evidence indicates that the composition of movement behaviours within a 24-h period is associated with multiple health benefits across the lifespan. A concept that emphasises an individual's active lifestyle is physical literacy (PL), yet empirical research exploring the potential associations between PL and 24-h movement guidelines remains scarce. This study aimed to evaluate the associations between levels of PL and adherence to the guidelines among Chinese university students. Study design: A cross-sectional study. Methods: Seven hundred and ninety-eight university students (390 male, 19.2 ± 1.2 years) completed all the measurements. Levels of PL and participants' adherence to guidelines including physical activity, sedentary behaviour and sleep were self-reported through Perceived Physical Literacy Instrument, International Physical Activity Questionnaire and Pittsburgh Sleep Quality Index, respectively. Two-way ANOVA was conducted to determine the associations between the number of guidelines met (0, 1, 2, or 3) and levels of PL. Results: The results demonstrate that 36.5% (n = 291) of the participants met all the three guidelines, while 4.1% (n = 33) met none. Further analysis indicated that meeting physical activity or sedentary behaviour guidelines was associated with significantly higher total PL scores, and scores in the sub-domains of Confidence and Physical Competence and Motivation. Conclusions: The findings provide evidence that young adults who obtained higher PL scores may meet more guidelines during a 24-h period. Future studies should incorporate accelerometer-based physical activity measurements and investigate the causal relationship between PL and adherence to the movement guidelines.

BMI is dead; long live waist-circumference indices: But which index should we choose to predict cardio-metabolic risk?

BACKGROUND AND AIMS: There is growing evidence that Body Mass Index (BMI) is unfit for purpose. Waist circumference (WC) indices appear to be the preferred alternative, although it is not clear which WC index is optimal at predicting cardio-metabolic risk (CMR) and associated health outcomes. METHODS AND RESULTS: We obtained a stratified random probability sample of 53,390 participants from the Health Survey for England (HSE), 2008-2018. The four available CMR factors were; high-density lipoproteins (HDL) cholesterol, glycated haemoglobin (HbA1c), systolic (SBP) and diastolic blood pressure (DBP). Strength of association between the four cardio-metabolic risk factors and competing anthropometric indicators of weight status [BMI, Waist-to-height ratio (WHTR), unadjusted WC, and a new WC index independent of height, WHT·5R = WC/height0.5] was assessed separately, using simple correlations and ANCOVAs, and together (combined) using MANCOVA, controlling for age, sex and ethnicity. Centile curves for the new index WHT·5R = WC/height0.5were also provided. CONCLUSIONS: Waist-circumference indices were superior to BMI when explaining/predicting our CMR factors, before and after controlling for age, sex and ethnicity. No single WC index was consistently superior. Results suggest that WHTR is the strongest predictor of HbA1c, confirming that shorter individuals are at great risk of diabetes. The most appropriate WC index associated with blood pressure was WHT·5R for DBP, or unadjusted WC for SBP. Given HDL cholesterol is independent of height, the best predictor of HDL was WHT.5R. Clearly, "no one size fits all!". MANCOVA identified WHT·5R to be the best single WC index associated with a composite of all four CMR factors.

UK university staff experience high levels of sedentary behaviour during work and leisure time.

Objective. Reducing sedentary behaviours at work is imperative. Before effective strategies can be developed there is a need to understand profiles of activity within particular roles and organizations. This study aimed to determine activity profiles of staff by job title at a UK university. Methods. Three-hundred and seventeen participants completed the international physical activity questionnaire - short form to determine physical activity profiles. Fifty-one participants also wore a wrist-worn GENEActiv accelerometer for 7 days and completed a self-report diary denoting work and leisure hours. Results. Twenty-one per cent of respondents were categorized as inactive and achieved 298 ± 178 metabolic equivalent minutes (MET-min)/week. Those in administrative roles were most sedentary (501 ± 161 min/day). Accelerometer data highlighted that sedentary time was identical between job roles (pooled mean 8746 ± 823 counts) and equated to 84 ± 9% of total time. During working hours, management, professional and specialist job roles had the highest level of sedentary time (2066 ± 416 counts). Conclusion. Time spent undertaking sedentary activities during working hours contributes to reduced overall activity and can impede productivity, performance and health. Interventions encouraging regular movement and preventing sedentary behaviours at work are therefore required.

Chronic Fragmentation of the Daily Sleep-Wake Rhythm Increases Amyloid-beta Levels and Neuroinflammation in the 3xTg-AD Mouse Model of Alzheimer's Disease.

Fragmentation of the daily sleep-wake rhythm with increased nighttime awakenings and more daytime naps is correlated with the risk of development of Alzheimer's disease (AD). To explore whether a causal relationship underlies this correlation, the present study tested the hypothesis that chronic fragmentation of the daily sleep-wake rhythm stimulates brain amyloid-beta (Aß) levels and neuroinflammation in the 3xTg-AD mouse model of AD. Female 3xTg-AD mice were allowed to sleep undisturbed or were subjected to chronic sleep fragmentation consisting of four daily sessions of enforced wakefulness (one hour each) evenly distributed during the light phase, five days a week for four weeks. Piezoelectric sleep recording revealed that sleep fragmentation altered the daily sleep-wake rhythm to resemble the pattern observed in AD. Levels of amyloid-beta (Aß40 and Aß42) determined by ELISA were higher in hippocampal tissue collected from sleep-fragmented mice than from undisturbed controls. In contrast, hippocampal levels of tau and phospho-tau differed minimally between sleep fragmented and undisturbed control mice. Sleep fragmentation also stimulated neuroinflammation as shown by increased expression of markers of microglial activation and proinflammatory cytokines measured by q-RT-PCR analysis of hippocampal samples. No significant effects of sleep fragmentation on Aß, tau, or neuroinflammation were observed in the cerebral cortex. These studies support the concept that improving sleep consolidation in individuals at risk for AD may be beneficial for slowing the onset or progression of this devastating neurodegenerative disease.

The influence of sleep health on dietary intake: a systematic review and meta-analysis of intervention studies.

BACKGROUND: Poor dietary intake increases disease risk, and poor sleep influences diet. This systematic review and meta-analysis of intervention studies aimed to evaluate the effect of sleep health on dietary intake in adults. METHODS: Five online databases were used to identify studies published between 1970 and 2019. Included studies were interventions that modified sleep and reported dietary outcomes. RESULTS: Fifty four full texts were assessed and 24 publications were included. Following risk of bias appraisal, data were narratively summarised and a sub-group of studies (n = 15) was meta-analysed to determine the effect of sleep on dietary intake. One intervention modified sleep timing and 23 modified duration. Sleep duration was partially restricted (≤5.5 h night-1 ) (n = 16), totally restricted (n = 4), partially and totally restricted (n = 1), and extended (n = 2). Dietary outcomes were energy intake (n = 24), carbohydrate, fat, protein intake (n = 20), single nutrient intake (n = 5), diet quality (n = 1) and food types (n = 1). Meta-analysis indicated partial sleep restriction results in higher energy intake in intervention compared with control [standardised mean difference (SMD) = 0.37; 95% confidence interval (CI) = 0.21-0.52; P < 0.001], with a mean difference of 204 kcal (95% CI = 112-295; P < 0.001) in daily energy intake, and a higher percentage of energy from fat, protein, carbohydrate (fat: SMD = 0.33; 95% CI = 0.16-0.51; P < 0.001; protein: SMD = 0.30, 95% CI = 0.12-0.47, P = 0.001; carbohydrate: SMD = 0.22, 95% CI = 0.04-0.39, P = 0.014). CONCLUSIONS: Partial sleep restriction with duration of ≤5.5 h day-1 increases daily energy intake, as well as fat, protein and carbohydrate intake. Further research is needed to determine the relationship between other dimensions of sleep health and dietary intake.

Objectively measured waist circumference is most strongly associated in father-boy and mother-girl dyads in a large nationally representative sample of New Zealanders.

BACKGROUND: The prevalence of children with elevated weight or obesity is concerning for public health due to associated comorbidities. This study investigates associations between parental adiposity, physical activity (PA), fruit and vegetable consumption, and child adiposity and moderation by both child and parent gender. METHODS: Cross-sectional nationally representative data from the New Zealand Health Survey were pooled for the years 2013/14-2016/17. Parent and child surveys were matched resulting in 13,039 child (2-14 years) and parent (15-70 years) dyads. Parent and child, height (cm), weight (kg) and waist circumference (WC) were measured objectively. Height and weight were used to calculate BMI. Linear regression, accounting for clustered samples (b [95% CI]) investigated associations between parental characteristics and child BMI z-score and WC. Interactions and stratification were used to investigate effect moderation by parent gender, child gender, and parent adiposity. RESULTS: Parental PA and fruit and vegetable consumption were unrelated to child adiposity. Overall, higher parent BMI was related to a higher child BMI z-score (b = 0.047 [0.042, 0.052]) and higher parental WC was related to a higher child WC (0.15 [0.12, 0.17]). A three-way interaction revealed no moderation by parent gender, child gender, and parent BMI for child BMI z-score ((b = 0.005 [-0.017, 0.027], p = 0.318). However, a three-way interaction revealed moderation by parent gender, child gender, and parent WC for child WC (b = 0.13 [0.05, 0.22]). The slightly stronger associations were seen between father-son WC (b = 0.20 [0.15, 0.24]) and mother-daughter WC (b = 0.19 [0.15, 0.22]). CONCLUSIONS: The findings are highly relevant for those wishing to understand the complex relationships between child-parent obesity factors. Findings suggest that family environments should be a key target for obesity intervention efforts and show how future public health interventions should be differentiated to account for both maternal and paternal influences on child adiposity.

Clusters of health behaviours in Queensland adults are associated with different socio-demographic characteristics.

BACKGROUND: The co-occurrence of unhealthy lifestyles, calls for interventions that target multiple health behaviours. This study investigates the clustering of health behaviours and examines demographic differences between each cluster. METHODS: In total, 934 adults from Queensland, Australia completed a cross-sectional survey assessing multiple health behaviours. A two-step hierarchical cluster analysis using multiple iterations identified the optimal number of clusters and the subset of distinguishing health behaviour variables. Univariate analyses of variance and chi-squared tests assessed difference in health behaviours by socio-demographic factors and clusters. RESULTS: Three clusters were identified: the 'lower risk' cluster (n = 436) reported the healthiest profile and met all public health guidelines. The 'elevated risk' cluster (n = 105) reported a range of unhealthy behaviours such as excessive alcohol consumption, sitting time, fast-food consumption, smoking, inactivity and a lack of fruit and vegetables. The 'moderate risk behaviour' cluster (n = 393) demonstrated some unhealthy behaviours with low physical activity levels and poor dietary outcomes. The 'elevated risk' cluster were significantly younger and more socio-economically disadvantaged than both the 'lower and moderate risk' clusters. DISCUSSION: Younger people who live in more deprived areas were largely within the 'elevated risk' cluster and represent an important population for MHBC interventions given their wide range of unhealthy behaviours.

Can you elaborate on that? Addressing participants' need for cognition in computer-tailored health behavior interventions.

Computer-tailored interventions, which deliver health messages adjusted based on characteristics of the message recipient, can effectively improve a range of health behaviours. Typically, the content of the message is tailored to user demographics, health behaviours and social cognitive factors (e.g., intentions, attitudes, self-efficacy, perceived social support) to increase message relevance, and thus the extent to which the message is read, considered and translated into attitude and behaviour change. Some researchers have suggested that the efficacy of computer-tailored interventions may be further enhanced by adapting messages to suit recipients' need for cognition (NFC) - a personality trait describing how individuals tend to process information. However, the likely impact of doing so, especially when tailored in conjunction with other variables, requires further consideration. It is possible that intervention effects may be reduced in some circumstances due to interactions with other variables (e.g., perceived relevance) that also influence information processing. From a practical point of view, it is also necessary to consider how to optimally operationalise and measure NFC if it is to be a useful tailoring variable. This paper aims to facilitate further research in this area by critically examining these issues based on relevant theories and existing evidence.

Activity of Streptococcus mutans VicR Is Modulated by Antisense RNA.

The VicRK 2-component system of Streptococcus mutans regulates genes associated with cell wall biogenesis and biofilm formation. A putative RNase III-encoding gene ( rnc) is located downstream from the vicRKX operon. The goals of this study were to investigate the potential role of VicR in the regulation of adjacent downstream genes and evaluate transcription levels of vicR during planktonic and biofilm growth. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to investigate whether vicRKX and adjacent downstream genes were cotranscribed. Binding of purified recombinant VicR protein to promoter regions of vicR, rnc, and syfA genes was confirmed by electrophoretic mobility shift assay and by chromatin immunoprecipitation analyses. VicR antisense (AS vicR) RNA was detected by Northern blotting and qRT-PCR assays. AS vicR overexpression mutants were constructed, and the biofilm biomass was determined by crystal violet microtiter assay. Adjacent downstream genes rnc, smc, syfA, smu.1511, and syfB were cotranscribed with vicRKX. The predicted promoter regions of vicR, rnc, and syfA genes were directly regulated by VicR. An AS vicR RNA transcript was detected upstream of the rnc gene. Expression of the AS vicR RNA transcript was elevated in planktonic cultures and repressed during biofilm growth. In addition, Western blot data showed that expression of the VicR protein decreased by 35% in planktonic as compared with biofilm cultures. Furthermore, we show that overexpression of AS vicR led to a reduction in biofilm formation. The downstream genes rnc, smc, syfA, smu.1511, and syfB are cotranscribed with vicRKX. VicR is autophosphorylated, and rnc and syfA are directly regulated by VicR. Expression of VicR protein correlated inversely with different levels of AS vicR RNA transcript and growth conditions. The biofilm biomass decreased in the AS vicR overexpression mutant. These data suggest a role for the AS vicR RNA transcript in posttranscriptional regulation of VicR protein production in S. mutans.

Effects of external loads on postural sway during quiet stance in adults aged 20-80 years.

The purpose of this study was to investigate the effects of holding external loads on postural sway during upright stance across age decades. Sixty-five healthy adults (females, n = 35), aged 18-80 years were assessed in four conditions; (1) standing without holding a load, holding a load corresponding to 5% body mass in the (2) left hand, (3) right hand and (4) both hands. The centre of pressure (COP) path length and anteroposterior and mediolateral COP displacement were used to indirectly assess postural sway. External loading elicited reductions in COP measures of postural sway in older age groups only (P < 0.05). No changes were observed in younger or intermediate aged adults (P > 0.05). Holding external loads during standing is relevant to many activities of daily living (i.e. holding groceries). The reduction in postural sway may suggest this type of loading has a stabilising effect during quiet standing among older adults.

Designing more engaging computer-tailored physical activity behaviour change interventions for breast cancer survivors: lessons from the iMove More for Life study.

BACKGROUND: Participating in regular physical activity is a recommended cancer recovery strategy for breast cancer survivors. However, tailored support services are not widely available and most survivors are insufficiently active to obtain health benefits. Delivering tailored programs via the Internet offers one promising approach. However, recent evaluations of such programs suggest that major improvements are needed to ensure programs meet the needs of users and are delivered in an engaging way. Understanding participants' experiences with current programs can help to inform the next generation of systems. PURPOSE: The purposes of this study are to explore breast cancer survivor's perspectives of and experiences using a novel computer-tailored intervention and to describe recommendations for future iterations. METHODS: Qualitative data from a sub-sample of iMove More for Life study participants were analysed thematically to identify key themes. Participants long-term goals for participating in the program were explored by analysing open-ended data extracted from action plans completed during the intervention (n = 370). Participants negative and positive perceptions of the website and recommendations for improvement were explored using data extracted from open-ended survey items collected at the immediate intervention follow-up (n = 156). RESULTS: The majority of participants reported multi-faceted goals, consisting of two or more outcomes they hoped to achieve within a year. While clear themes were identified (e.g. 'being satisfied with body weight'), there was considerable variability in the scope of the goal (e.g. desired weight loss ranged from 2 to 30 kg). Participants' perceptions of the website were mixed, but clear indications were provided of how intervention content and structure could be improved. CONCLUSIONS: This study provides insight into how to better accommodate breast cancer survivors in the future and ultimately design more engaging computer-tailored interventions.

A gut reaction: the combined influence of exercise and diet on gastrointestinal microbiota in rats.

AIMS: Intestinal microbiota modulates the development of clinical conditions, including metabolic syndrome and obesity. Many of these conditions are influenced by nutritional and exercise behaviours. This study aimed to investigate the ability of exercise to re-shape the intestinal microbiota and the influence of the diet on the process. METHODS AND RESULTS: A rat model was used to examine the intestinal microbiota responses to four activity conditions, including: high-intensity interval training (HIIT), light-intensity training (LIT), sedentary and normal control, each containing two nutritional conditions: high-fat high-fructose diet (HF) and standard chow (SC) diet. No significant differences in microbiota were apparent between activity conditions in rats fed a HF diet but changes in the presence/absence of phylotypes were observed in the LIT and HIIT groups. In rats fed SC, significant differences in intestinal microbiota were evident between exercised and nonexercised rats. Both LIT and HIIT induced significant differences in intestinal microbiota in SC-fed rats compared to their respective SC-fed controls. Characterization of the exercise-induced bacterial phylotypes indicated an increase in bacteria likely capable of degrading resistant polysaccharides and an increase in short chain fatty acid producers. CONCLUSIONS: While a significant effect of exercise on microbiota composition occurred in SC-fed rats, the HF-fed rats microbiota showed little response. These data suggest that a HF diet prevented microbiota differentiation in response to exercise. SIGNIFICANCE AND IMPACT OF THE STUDY: The importance of diet-exercise interaction is extended to the level of intestinal bacteria and gut health.

Is the Ergogenicity of Caffeine Affected by Increasing Age? The Direct Effect of a Physiological Concentration of Caffeine on the Power Output of Maximally Stimulated EDL and Diaphragm Muscle Isolated from the Mouse.

INTRODUCTION: Caffeine is a well-established performance enhancing nutritional supplement in a young healthy population, however far less is known about how its ergogenicity is affected by increasing age. A recent review has highlighted the value of studies examining the direct effect of caffeine on isolated skeletal muscle contractility, but the present work is the first to assess the direct effect of 70µM caffeine (physiological maximum) on the maximal power output of isolated mammalian muscle from an age range representing developmental to early ageing. METHOD: Female CD1 mice were aged to 3, 10, 30 and 50 weeks (n = 20 in each case) and either whole EDL or a section of the diaphragm was isolated and maximal power output determined using the work loop technique. Once contractile performance was maximised, each muscle preparation was treated with 70µM caffeine and its contractile performance was measured for a further 60 minutes. RESULTS: In both mouse EDL and diaphragm 70µM caffeine treatment resulted in a significant increase in maximal muscle power output that was greatest at 10 or 30 weeks (up to 5% and 6% improvement respectively). This potentiation of maximal muscle power output was significantly lower at the early ageing time point, 50 weeks (up to 3% and 2% improvement respectively), and in mice in the developmental stage, at 3 weeks of age (up to 1% and 2% improvement respectively). CONCLUSION: Uniquely, the present findings indicate a reduced age specific sensitivity to the performance enhancing effect of caffeine in developmental and aged mice which is likely to be attributed to age related muscle growth and degradation, respectively. Importantly, the findings indicate that caffeine may still provide a substantial ergogenic aid in older populations which could prove important for improving functional capacity in tasks of daily living.

How do different delivery schedules of tailored web-based physical activity advice for breast cancer survivors influence intervention use and efficacy?

PURPOSE: The purpose of the study is to investigate the impact of differing delivery schedules of computer-tailored physical activity modules on engagement and physical activity behaviour change in a web-based intervention targeting breast cancer survivors. METHODS: Insufficiently active breast cancer survivors (n = 492) were randomly assigned to receive one of the following intervention schedules over 12 weeks: a three-module intervention delivered monthly, a three-module intervention delivered weekly or a single module intervention. Engagement with the website (number of logins, time on site, modules viewed, action plans completed) was measured using tracking software. Other outcomes (website acceptability, physical activity behaviour) were assessed using online surveys. Physical activity outcomes were analysed using regression models for both study completers and when applying intention-to-treat (using multiple imputation). RESULTS: Completers allocated to the monthly module group rated the intervention higher (b = 2.2 95 % CI = 0.02-4.53) on acceptability and had higher levels of resistance-training (IRR = 1.88, 95 % CI = 1.16-3.04) than those in the single module group. When accounting for missing data, these differences were no longer significant. The completion of at least two action plans was higher among those allocated to the monthly module group compared to those in the weekly module group (53 vs 40 %, p = 0.02); though the completion of at least two modules was higher in the weekly module group compared to the monthly module group (60 vs 46 %; p = 0.01). There were no other significant between group differences observed. CONCLUSION: This study provides preliminary evidence that web-based computer-tailored interventions can be used to increase physical activity among breast cancer survivors. Further, there were some outcome differences based on how the tailored modules were delivered, with the most favourable outcomes observed in the monthly delivery group. IMPLICATIONS FOR CANCER SURVIVORS: This study will be useful for informing the design of future web-based interventions targeting breast cancer survivors.

Scaling waist girth for differences in body size reveals a new improved index associated with cardiometabolic risk.

Our aim was to examine whether a new ratio, waist divided by height0.5 (WHT.5R), is both independent of stature and a stronger predictor of cardiometabolic risk (CMR) than other anthropometric indices. Subjects (4117 men and 646 women), aged 20-69 years, were assessed for stature (cm), mass (kg), waist, and hip girths (cm) from which body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHTR), and two new indices, a body shape index (ABSI) and WHT.5R, were determined. We used the allometric power law, W = a.HTb , to obtain a simple body shape index for waist girth (W) to be independent of stature (HT). Physical activity was determined using self-report, and physical fitness was determined using the Bruce protocol. Glucose, total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, and TC/HDL ratio were determined from fasting venous blood samples. A single CMR composite score was derived from log-transformed z-scores of Triglycerides + average blood pressure ((diastolic + systolic)/2) + glucose + HDL (*-1). Results confirmed WHT.5R to be independent of stature and the strongest predictor of CMR, compared with BMI, WC, WHR, ABSI, and WHTR. We also found that CMR scores decline significantly with increasing fitness and physical activity, confirming that being fit and active can compensate for the adverse effects of being fat as measured by all other anthropometric indices. In conclusion, WHT.5R was the best anthropometric index associated with CMR, and being both physically fit and active has a protective effect on CMR, irrespective of weight status.

Restricting feeding to the active phase in middle-aged mice attenuates adverse metabolic effects of a high-fat diet.

Time-restricted feeding ameliorates the deleterious effects of a high-fat diet on body weight and metabolism in young adult mice. Because obesity is highly prevalent in the middle-aged population, this study tested the hypothesis that time-restricted feeding alleviates the adverse effects of a high-fat diet in male middle-aged (12months) mice. C57BL6/J mice were fed one of three diets for 21-25weeks: 1) high-fat diet (60% total calories from fat) ad-libitum (HFD-AL), 2) HFD, time-restricted feeding (HFD-TRF), and 3) low-fat diet (10% total calories from fat) ad-libitum (LFD-AL) (n=15 each). HFD-TRF mice only had food access for 8h/day during their active period. HFD-TRF mice gained significantly less weight than HFD-AL mice (~20% vs 55% of initial weight, respectively). Caloric intake differed between these groups only during the first 8weeks and accounted for most but not all of their body weight difference during this time. TRF of a HFD lowered glucose tolerance in terms of incremental area under the curve (iAUC) (p<0.02) to that of LFD-AL mice. TRF of a HFD lowered liver weight (p<0.0001), but not retroperitoneal or epididymal fat pad weight, to that of LFD-AL mice. Neither HFD-AL nor HFD-TRF had any effect on performance in the novel object recognition or object location memory tests. Circulating corticosterone levels either before or after restraint stress were not affected by diet. In conclusion, TRF without caloric restriction is an effective strategy in middle-aged mice for alleviating the negative effects of a HFD on body weight, liver weight, and glucose tolerance.

An integrated curriculum approach to increasing habitual physical activity in deprived South Asian children.

Integrating physical activity (PA) within a school curriculum is a promising approach for increasing PA in children. To date, no research has examined its effectiveness in increasing the low levels of PA witnessed in deprived South Asian (SA) children. The study aims to ascertain whether an integrated school-based curriculum and pedometer intervention could increase PA in children from deprived SA backgrounds. Following ethical approval and informed consent, 134 deprived SA children (63 boys, 71 girls, control (n = 40, mean age = 11.12 years, SD = 0.32 years) and intervention (n = 94, mean age = 9.48 years, SD = 0.62 years)) from a primary school in England, UK, completed a 6-week integrated PA intervention based on virtually walking from their school (middle of the country) to the coast and back (March-July 2013). Habitual PA was determined at baseline and post 6 weeks intervention for both groups, and determined weekly during the intervention in the experimental group. The results indicated that average daily steps were significantly higher at post 6 weeks compared to baseline for the intervention group (intervention mean change = 8694 steps/day, SD = 7428 steps/day vs. control mean change = -1121 steps/day, SD = 5592 steps/day, 95% CI of difference, 6726-7428 steps/day, P = .001, d = 1.76). In addition, significant decreases in BF% and waist circumference were observed in the intervention group post 6 weeks (mean change for BF% = -4.5%, mean change for WC = -1.7 cm, P = .001). School-based integrated curriculum and pedometer interventions provide a feasible and effective mechanism for increasing habitual PA in primary school children from deprived SA backgrounds.

TaylorActive--Examining the effectiveness of web-based personally-tailored videos to increase physical activity: a randomised controlled trial protocol.

BACKGROUND: Physical inactivity levels are unacceptably high and effective interventions that can increase physical activity in large populations at low cost are urgently needed. Web-based interventions that use computer-tailoring have shown to be effective, though people tend to 'skim' and 'scan' text on the Internet rather than thoroughly read it. The use of online videos is, however, popular and engaging. Therefore, the aim of this 3-group randomised controlled trial is to examine whether a web-based physical activity intervention that provides personally-tailored videos is more effective when compared with traditional personally-tailored text-based intervention and a control group. METHODS/DESIGN: In total 510 Australians will be recruited through social media advertisements, e-mail and third party databases. Participants will be randomised to one of three groups: text-tailored, video-tailored, or control. All groups will gain access to the same web-based platform and a library containing brief physical activity articles. The text-tailored group will additionally have access to 8 sessions of personalised physical activity advice that is instantaneously generated based on responses to brief online surveys. The theory-based advice will be provided over a period of 3 months and address constructs such as self-efficacy, motivation, goal setting, intentions, social support, attitudes, barriers, outcome expectancies, relapse prevention and feedback on performance. Text-tailored participants will also be able to complete 7 action plans to help them plan what, when, where, who with, and how they will become more active. Participants in the video-tailored group will gain access to the same intervention content as those in the text-tailored group, however all sessions will be provided as personalised videos rather than text on a webpage. The control group will only gain access to the library with generic physical activity articles. The primary outcome is objectively measured physical activity. Secondary outcomes include website engagement and retention, quality of life, depression, anxiety, stress, sitting time, sleep and psychosocial correlates of physical activity. Outcomes will be measured at baseline, 3, and 9 months. DISCUSSION: This study presents an ideal opportunity to study the effectiveness of an isolated feature within a web-based physical activity intervention and the knowledge generated from this study will help to increase intervention effectiveness. TRIAL REGISTRATION: Australian New-Zealand Clinical Trial Registry: ACTRN12615000057583 . Registered 22 January 2015. CQUniversity Ethics Project Number: H14/07-163.

Effects of acute caffeine ingestion on resistance training performance and perceptual responses during repeated sets to failure.

AIM: The aim of the present study was to evaluate the effect of oral caffeine ingestion during repeated sets of resistance. METHODS: Fourteen moderately resistance-trained men (20.9 ± 0.36 years and 77.62 ± 2.07 kg of body weight) ingested a dose of caffeine (5 mg.kg-1) or placebo prior to 3 sets of bench press and 3 sets of leg press exercises, respectively. The study used a double-blind, counterbalanced, crossover design. Repetitions completed and total weight lifted were recorded in each set. Readiness to invest in both physical (RTIPE) and mental (RTIME) effort were assessed prior each set, and rating of perceived exertion (RPE) was recorded after each set. Rest and peak heart rates were determined via telemetry. RESULTS: Caffeine ingestion result in increased number of repetitions to failure in bench press (F[1,13]=6.16, P=0.027) and leg press (F[1,13]=9.33, P=0.009) compared to placebo. The sum of repetitions performed in the 3 sets was 11.60% higher in bench press (26.86 ± 1.74; caffeine: 30.00 ± 1.87; P=0.027) and 19.10% in leg press (placebo: 40.0 ± 4.22; caffeine: 47.64 ± 4.69; P=0.009). Also, RTIME was increased in the caffeine condition both in bench press (F[1,13]=7.02, P=0.02) and in leg press (F[1,13]=5.41, P=0.03). There were no differences in RPE, RTIPE and HR (P>0.05) across conditions. CONCLUSION: Acute caffeine ingestion can improve performance in repeated sets to failure and increase RTIME in resistance-trained men.

Effect of arousing stimuli on circulating corticosterone and the circadian rhythms of luteinizing hormone (LH) surges and locomotor activity in estradiol-treated ovariectomized (ovx+EB) Syrian hamsters.

In most proestrous hamsters, novel wheel exposure phase advances activity rhythms and blocks the preovulatory LH surge, which occurs 2h earlier the next day. Because wheel immobilization does not prevent these effects we hypothesized that arousal alone blocks and phase advances the LH surge. Ovariectomized (ovx) hamsters received a jugular vein cannula and estradiol benzoate (EB) or vehicle was injected sc. The next day (Day 1), at zeitgeber time (ZT) 4-5 (ZT 12 = lights off), after obtaining a blood sample, each hamster was exposed to constant darkness (DD), and either remained in her home cage or was transferred to a new cage and exposed to a running wheel or a 2-hour arousal paradigm. Blood samples were obtained in dim red light and activity was recorded hourly until ~ZT 10-11 on Days 1 and 2. For the next 1-2 weeks, activity was monitored in DD. Plasma LH and corticosterone were assessed by RIA. Novel wheel exposure or arousal at ZT 4 greatly attenuated the Day 1 LH surge in ovx+EB hamsters, and phase advanced the Day 2 LH surge by about 2h. In proestrous hamsters, novel wheel exposure led to a prolonged (>2h) increase in corticosterone levels only when LH surges were blocked. Phase advances in activity rhythms were enhanced by estradiol and arousal. The results suggest that estradiol modulates the effectiveness of non-photic stimuli. The role of the increased activity of the hypothalamic-pituitary-adrenal axis associated with novel wheel-induced attenuation of LH surges in ovx+EB hamsters remains to be determined.