Effect of different intensities of physical activity on cardiometabolic markers and vascular and cardiac function in adult rats fed with a high-fat high-carbohydrate diet

Background: Physical activity(PA) and diet are 2 lifestyle factors that affect cardiometabolic risk. However, data on how a high-fat highcarbohydrate(HFHC) diet influences the effect of different intensities of PA on cardiometabolic health and cardiovascular function in a controlled setting are yet to be fully established. This study investigated the effect of sedentary behavior, light-intensity training(LIT), and high-intensity interval training(HIIT) on cardiometabolic markers and vascular and cardiac function in HFHC-fed adult rats.Methods: Twelve-week-old Wistar rats were randomly allocated to 4 groups(12 rats/group): control(CTL), sedentary(SED), LIT, and HIIT.Biometric indices, glucose and lipid control, inflammatory and oxidative stress markers, vascular reactivity, and cardiac electrophysiology of the experimental groups were examined after 12 weeks of HFHC-diet feeding and PA interventions.Results: The SED group had slower cardiac conduction(p = 0.0426) and greater thoracic aortic contractile responses(p < 0.05) compared with the CTL group. The LIT group showed improved cardiac conduction compared with the SED group(p = 0.0003), and the HIIT group showed decreased mesenteric artery contractile responses compared with all other groups and improved endothelium-dependent mesenteric artery relaxation compared with the LIT group(both p < 0.05). The LIT and HIIT groups had lower visceral(p = 0.0057 for LIT, p = 0.0120 for HIIT)and epididymal fat(p < 0.0001 for LIT, p = 0.0002 for HIIT) compared with the CTL group.Conclusion: LIT induced positive adaptations on fat accumulation and cardiac conduction, and HIIT induced a positive effect on fat accumulation,mesenteric artery contraction, and endothelium-dependent relaxation. No other differences were observed between groups. These findings suggest that few positive health effects can be achieved through LIT and HIIT when consuming a chronic and sustained HFHC diet.

Acceptability,usefulness,and satisfaction with a web-based video-tailored physical activity intervention:The TaylorActive randomized controlled trial

Purpose:This study aimed to examine the usage,acceptability,usability,perceived usefulness,and satisfaction of a web-based video-tailored physical activity(PA)intervention(TaylorActive)in adults.Methods:In 2013-2014,501 Australian adults aged 18+years were randomized into a video-tailored intervention,text-tailored intervention,or control group.Over 3 months,the intervention groups received access to 8 sessions of personally tailored PA advice delivered via the TaylorActive website.Only the delivery method differed between the intervention groups:video-tailored vs.text-tailored.Google Analytics and telephone surveys conducted at post intervention(3 months)were used to assess intervention usage,acceptability,usability,perceived usefulness,and satisfaction.Quantitative and qualitative process data were analyzed using descriptive statistics and thematic content analysis.Results:Of 501 recruited adults,259 completed the 3-month post-intervention survey(52%retention).Overall,usage of the TaylorActive website with respect to number of website visits,intervention sessions,and action plans completed was modest in both the video-tailored(7.6士7.2 visits,mean±SD)and text-tailored(7.3±5.4 visits)groups with no significant between-group differences.The majority of participants in all groups used the TaylorActive website less than once in 2 weeks(66.7%video-tailored,62.7%text-tailored,87.5%control;p<0.001).Acceptability was rated mostly high in all groups and in some instances,significantly higher in the intervention groups compared to the control group(p<0.010).Usability was also rated high;mean Systems Usability Scores were 77.3(video-tailored),75.7(text-tailored),and 74.1(control)with no significant between-group differences.Perceived usefulness of the TaylorActive intervention was low,though mostly rated higher in the intervention groups compared to the control group(p<0.010).Satisfaction with the TaylorActive website was mixed.Participants in both intervention groups liked its ease of use,personalized feedback,and tracking of progress,but also found completing action plans and survey questions for each session repetitive and tedious.Conclusion:Providing personally tailored PA advice on its own(through either video or text)is likely insufficient to ensure good retention,usage,perceived usefulness,and satisfaction with a web-based PA intervention.Strategies to address this may include the incorporation of additional intervention components such as activity trackers,social interactions,gamification,as well as the use of advanced artificial intelligence and machine learning technologies to allow more personalized dialogue with participants.

Associations between aerobic and muscle-strengthening physical activity,sleep duration,and risk of all-cause mortality:A prospective cohort study of 282,473 U.S.adults

Purpose:To examine the joint associations between meeting guidelines for physical activity(PA)and sleep duration and all-cause mortality risk among adults.Methods:Participants were adults(n=282,473)aged 18-84 years who participated in the 2004-2014 U.S.National Health Interview Survey.Mortality status was ascertained using the National Death Index through December 2015.Self-reported PA(Active:meeting both aerobic(AER)and muscle-strengthening(MSA)guidelines,AER only(AER),MSA only(MSA),or not meeting either AER or MSA(Inactive))and sleep duration(Short,recommended(Rec),or Long)were classified according to guidelines,and 12 PA-sleep categories were derived.Adjusted hazard ratios and 95%confidence intervals(95%CIs)for all-cause mortality risk were estimated using Cox proportional hazards regression models.Results:A total of 282,473 participants(55%females)were included;18,793 deaths(6.7%)occurred over an average follow-up of 5.4 years.Relative to the Active-Rec group,all other PA-sleep groups were associated with increased mortality risk except for the Active-Short group(hazard ratio=1.08;95%CI:0.92-1.26).The combination of long sleep with either MSA or Inactive appeared to be synergistic.For a given sleep duration,mortality risk progressively increased among participants classified as AER,MSA,and Inactive.Within each activity level,the mortality risk was greatest among adults with long sleep.Conclusion:Relative to adults meeting guidelines for both PA and sleep duration,adults who failed to meet guidelines for both AER and muscle strengthening PA and who also failed to meet sleep duration guidelines had elevated all-cause mortality risks.These results support interventions targeting both PA and sleep duration to reduce mortality risk.

Prospective associations between joint categories of physical activity and insomnia symptoms with onset of poor mental health in a population-based cohort

Background:Physical inactivity and insomnia symptoms are independently associated with increased risk of depression and anxiety;however,few studies jointly examine these risk factors.This study aimed to prospectively examine the joint association of physical activity(PA)and insomnia symptoms with onset of poor mental health in adults.Methods:Participants from the 2013 to 2018 annnual waves of the Household Income and Labour Dynamics in Australia panel study who had good mental health(Mental Health Inventory-5>54)in 2013,and who completed at least 1 follow-up survey(2014-2018),were included(n=10,977).Poor mental health(Mental Health Inventory-5≤54)was assessed annually.Baseline(2013)PA was classified as high/moderate/low,and insomnia symptoms(i.e.,trouble sleeping)were classified as no insomnia symptoms/insomnia symptoms,with 6 mutually exclusive PAinsomnia symptom groups derived.Associations of PA-insomnia symptom groups with onset of poor mental health were examined using discrete-time proportional-hazards logit-hazard models.Results:There were 2322 new cases of poor mental health(21.2%).Relative to the high PA/no insomnia symptoms group,there were higher odds(odds ratio and 95%confidence interval(95%CI))of poor mental health among the high PA/insomnia symptoms(OR=1.87,95%CI:1.57-2.23),moderate PA/insomnia symptoms(OR=1.93,95%CI:1.61-2.31),low PA/insomnia symptoms(OR=2.33,95%CI:1.96-2.78),and low PA/no insomnia symptoms(OR=1.14,95%CI:1.01-1.29)groups.Any level of PA combined with insomnia symptoms was associated with increased odds of poor mental health,with the odds increasing as PA decreased.Conclusion:The se findings highlight the potential benefit of interventions targeting both PA and insomnia symptoms for promoting mental health.

Body size, physical activity, and exposure to television in preschoolers

Objective: To investigate relationships between preschool-aged children’s body size and physiccal activity, exposure to television (TV), and parental body size. Design and subjects: Cross-sectional study of 80 children (age: 2 - 5 y, 29% overweight or obese), 73 mothers (37% overweight or obese), and 22 fathers (72% overweight or obese), residing in Auckland, New Zealand, between October 2006 and July 2007. Measurements: Body size was determined using waist circumference and body mass index (BMI). Child exposure to TV was assessed by questionnaire (number of household TV sets, presence of TV in the child’s bedroom, mean TV/ movie watching hours on weekdays and weekend days), and physical activity by 7 days of accelerometry. Results: Compared with children of normal weight/underweight mothers (classified by BMI status), the age-adjusted odds of a child being overweight/obese if their mother was over-weight/obese/otherwise was 2.46 (95% CI 1.11, 5.48, P = 0.03). No other associates of child body size were identified. Conclusion: Contributors to overweight and obesity in preschool aged children are complex and likely to exist in multiple facets of young children’s lives. More detailed measurement of TV watching and other sedentary behaviours is needed. An ecological approach to identifying risk factors for increased body size in preschoolers is required.

Demographic variations in discrepancies between objective and subjective measures of physical activity

Demographic effects (sex and parenthood status) on the level of association between self-reported and accelerometer assessed physical activity were examined among a large diverse sample of adults. Participants (N = 1,249, aged 20 - 65 years) wore accelerometers (Actical) for 7 days and completed an interviewer-administered physical activity recall questionnaire (IPAQ- LF) for the same period. Mean daily minutes of moderate physical activity (MPA) and moderate to vigorous physical activity (MVPA) were used in analyses. Linearity between methods was explored by regressing mean minutes of activity and Pearson’s correlations were performed. A weak association between IPAQ-LF and Actical minutes of MPA and MVPA per day was shown for the whole sample (rs = 0.216 – 0.260). The magnitude of association varied between males (rs = 0.265 – 0.366) and females (rs = 0.124 – 0.167), although no obvious variations in associations were evident for parenting status. The IPAQ-LF produced substantially greater variations in estimates of physical activity than that recorded by the Actical accelerometer and large discrepancies between methods were observed at an individual level. Self-report tools provide a poor proxy of overall human movement, particularly among females. Inferences made at an individual level from self-reported data, such as intervention efficacy or health outcomes, may have substantial error.

Cardiorespiratory and muscular fitness associations with older adolescent cognitive control

Background:Participation in physical activity supports greater cardiorespiratory fitness(CRF),a correlate of cognitive control.However,the relationship between muscular fitness(MF)and cognitive control is less clear.The present study investigated the differential relationship of CRF and MF with cognitive control in older adolescents.Methods:This cross-sectional study involved students(1517 years old,n=541,43%female)from 20 secondary schools who completed tests of inhibition(modified flanker task),working memory(n-back task),CRF(Progressive Aerobic Cardiovascular Endurance Run),and MF(standing long jump and push-up test).Multilevel analyses tested the association between CRF or MF and cognitive outcomes while accounting for the influence of the other fitness variable and relevant demographic factors.Results:CRF predicted response accuracy during incongruent flanker trials,the condition requiring greater inhibition.For the working memory task,CRF predicted greater target accuracy and greater d’scores on the 1-back task,requiring lesser amounts of working memory.In the 2-back task,which requires greater amounts of working memory,CRF also predicted greater target and non-target accuracy and d’scores.Comparatively,MF did not predict any cognitive outcomes after adjustment for CRF.Conclusion:CRF was selectively related to better performance during task conditions that require greater amounts of inhibition and working memory.This finding suggests that CRF,but not MF,may benefit cognitive control in older adolescents.This selective influence of CRF on older adolescents’cognition highlights the value of aerobic physical activity.

Impact on dietary intake of a self-directed, gender-tailored diabetes prevention program in men

AIMTo investigate changes in dietary intake following a 6-mo randomised controlled trial of the self-directed, gender-tailored type 2 diabetes mellitus (T2DM) Prevention Using LifeStyle Education (PULSE) program in men. METHODSMen aged 18-65 years, with a body mass index (BMI) 25-40 kg/m2, and at high risk for developing T2DM were recruited from the Hunter Region of New South Wales, Australia. Eligible participants were randomised into one of two groups: (1) waitlist control; or (2) PULSE intervention. Dietary intake was assessed at baseline and immediately post-program using the Australian Eating Survey food frequency questionnaire and diet quality measured using the Australian Recommended Food Score (ARFS). RESULTSOne hundred and one participants (n = 48, control; n = 53, intervention, mean age 52.3 ± 9.7 years, BMI of 32.6 ± 3.3 kg/m2) commenced the study. Following the active phase, differences between groups were observed for proportion of total energy consumed from healthful (core) foods (+7.6%EI, P < 0.001), energy-dense, nutrient-poor foods (-7.6%EI, P < 0.001), sodium (-369 mg, P = 0.047), and diet quality (ARFS) (+4.3, P = 0.004), including sub-scales for fruit (+1.1, P = 0.03), meat (+0.9, P = 0.004) and non-meat protein (+0.5, P = 0.03). CONCLUSIONThe PULSE prevention program’s nutrition messages led to significant improvements in dietary intake in men at risk of T2DM.