Influence of aerobic fitness on vasoreactivity in young men.

Previous work has demonstrated a direct relationship between aerobic fitness and vasodilatory function (i.e., flow-mediated dilation; FMD); however, the relation between aerobic fitness and vasoconstrictor responsiveness (i.e., low flow-mediated constriction; L-FMC), and the overall vasoactive range (FMD + L-FMC) is unclear. PURPOSE: To test the hypothesis that L-FMC and the overall vasoactive range (FMD + L-FMC) will be related to aerobic fitness in young, healthy men. METHODS: Twenty men (age: 23 ± 5 years) were recruited, and divided evenly into a higher (HF) vs. lower (LF) aerobic fitness group, quantified via YMCA cycle ergometry (VO2 peak extrapolation), and a 3-min step test (1-min heart rate recovery). Duplex Doppler-ultrasound was used to assess brachial artery FMD and L-FMC. RESULTS: Estimated VO2 peak (HF = 55 ± 10 vs. LF = 38 ± 5 mL/kg/min) and heart rate recovery (HF = 36 ± 10 vs. LF = 25 ± 8 beats) were greater in the HF group (P < 0.05). FMD and the vasoactive range were similar between groups; however, L-FMC was significantly greater in HF (HF = -2.5 ± 1.6 vs. LF = -0.7 ± 1.8%, P < 0.05; d = 1.18). A correlational analysis revealed an inverse relationship between L-FMC and both HR recovery (r = -0.665, P < 0.01) and estimated VO2 peak (r = -0.5, P < 0.05). CONCLUSIONS: This work supports an association between L-FMC and aerobic fitness in young, healthy men. Longitudinal or interventional studies are warranted to support causality, and to distinguish whether L-FMC is more sensitive to changes in aerobic fitness than FMD.

Understanding Health Behaviors, Weight Perceptions, and Body Appreciation of Young Adult Women Engaged in the Body Positivity Movement.

BACKGROUND: The body positivity movement on social media is thought to foster body appreciation, but pervasive societal concern persists about the body positivity movement and the body image, health behaviors, and "normalization of obesity" of young adult women. PURPOSE: This study explored the relationship between engagement in the body positivity movement on social media and weight status, body appreciation, body dissatisfaction, and the health behaviors of intuitive eating and physical activity in young adult women (18-35 years). METHODS: Participants (N = 521; ∼64% engaged in body positivity content on social media) were recruited using Qualtrics online panels for this cross-sectional survey during February 2021. Outcomes included weight status, weight consideration, weight perception, body appreciation, body dissatisfaction, physical activity, and intuitive eating. Logistic and linear regression models adjusted for age, race, ethnicity, education level, and household income were used to assess the association between engagement in the body positivity movement and specified outcomes. RESULTS: Engagement with body positivity content was associated with greater body dissatisfaction (ß = 2.33, t(519) = 2.90 p = .017), body appreciation (ß = 0.26, t(519) = 2.90 p = .004), and greater likelihood of reporting high amounts of physical activity (odds ratio = 2.28; p < .05) relative to nonengaged peers; these associations remained significant after further adjustment for weight status. Body positivity engagement was not associated with weight status, weight perception, or intuitive eating. CONCLUSIONS: Engagement in the body positivity movement is associated with higher body dissatisfaction and body appreciation in young adult women, which suggests they may be drawn to and engage in the body positivity movement as a protective or coping mechanism for body dissatisfaction.

Occupational sitting and work engagement among university employees.

Objective: This study sought to determine the relationship between occupational sitting and work engagement among university employees. Participants: Participants included 103 university employees (age: 48.5 ± 10.4 years, 80% female, 77% staff). Methods: Participants completed an online survey based on the Utrecht Work Engagement Survey (UWES) and the Occupational Sitting and Physical Activity Questionnaire (OSPAQ). The UWES assessed elements of work engagement. The OSPAQ assessed time spent sitting, standing, walking, and in heavy labor during a workday. Results: Compared to staff members, faculty members self-reported less time seated during the workday (373.8 ± 109.7 min/day vs. 321.1 ± 97.3 min/day, p = 0.03). Work engagement was comparable among faculty and staff members (vigor: p = 0.44; absorption: p = 0.68; dedication: p = 0.71). Associations of work engagement with occupational sitting were not significant. Conclusions: These pilot findings suggest that university staff tend to engage in more occupational sitting compared to faculty. Being absorbed and engaged at work is not associated with occupational sitting.

Impact of Acute Uninterrupted Sitting on Cerebrovascular Hemodynamics.

Reductions in brain blood flow are associated with reduced cognitive function and cerebrovascular disease. Acute periods of uninterrupted sitting can lead to endothelial dysfunction, namely due to a reduction in shear stress and subsequent reduction in nitric oxide bioavailability. Little is known of the impact of sitting on brain health. The purpose was to determine the total brain blood flow response following a 60-minute bout of uninterrupted sitting. Using a parallel design, this study evaluated the impact of 60-minutes of sitting on total brain blood flow. Fifteen participants (n=15; age=24 ± 1yr; BMI=25 ± 1 kg/m2) sat, uninterrupted, for 60-minutes during the SIT protocol. To ascertain the contribution of blood pooling effects on total brain blood flow, ten participants (n=10; age=23±2yr; BMI=27±4 kg/m2) sat in a modified sitting (MOD) for 60-minutes. Finally, thirteen participants (n=13; age=23±3yr; BMI=26±4 kg/m2) remained supine for the duration of the 60-minutes as a time-control (TC). Brain blood flow was quantified through Doppler-ultrasound measurements of blood flow through the internal carotid (ICA) and vertebral (VA) arteries: (ICA blood flow + VA blood flow) × 2. Following the 60-minutes of sitting (SIT), there was a significant reduction in brain blood flow with time (p=0.001, η p 2 =0.05). Total brain blood flow did not significantly change in MOD (p=0.69, η p 2 =0.05) or TC (p=0.06, η p 2 =0.58) conditions. These findings indicate 60-minutes of sitting may alter cerebrovascular hemodynamics characterized by a reduction in total brain blood flow.

Physical activity participation, flourishing and academic engagement in adolescents with obesity.

BACKGROUND: Adolescents with obesity are less likely to flourish and be academically engaged in comparison to their healthy weight peers. However, it is unknown how participation in physical activity influences flourishing and academic engagement in adolescents with obesity. The current study examined engagement in varying levels of physical activity and the likelihood of flourishing and academic engagement in adolescents with obesity. METHODS: Analyses included 26 764 adolescents, ages 10-17 years, from the parent-reported, combined 2016-2017 National Survey of Children's Health. Participants were grouped by physical activity levels (none, low, moderate, daily). Outcome variables included flourishing (finishing tasks, staying calm when faced with a challenge and showing interest in new things) and academic engagement (completing all required homework and caring about doing well in school). Logistic regression models, adjusted for age, sex, race, household income, highest level of education in the household, behavioural conduct problems and depression assessed the likelihood of each outcome comparing physical activity levels among adolescents with obesity. RESULTS: Adolescents with obesity who participated in any amount of physical activity (low, moderate and daily) or sports had significantly greater likelihood of flourishing and academic engagement compared those that did not engage in any physical activity (p's < 0.05). CONCLUSIONS: Participation in even low amounts of physical activity or participation in sports increases the likelihood of flourishing and academic engagement in adolescents with obesity, which expands on previous findings that adolescents with obesity are less likely to flourish and be academically engaged in comparison to their healthy weight peers.

Obesity, physical activity, and sedentary behaviors in adolescents with autism spectrum disorder compared with typically developing peers.

Decreased engagement in beneficial physical activity and increased levels of sedentary behavior and unhealthy weight are a continued public health concern in adolescents. Adolescents with autism spectrum disorder may be at an increased risk compared with their typically developing peers. Weekly physical activity, sedentary behavior, and body mass index classification were compared among adolescents with and without autism spectrum disorder. Analyses included 33,865 adolescents (autism spectrum disorder, n = 1036) from the 2016-2017 National Survey of Children's Health (United States). After adjustment for covariates, adolescents with autism spectrum disorder were found to engage in less physical activity and were more likely to be overweight and obese compared with their typically developing peers (p's < 0.05). As parent-reported autism spectrum disorder severity increased, the adjusted odds of being overweight and obese significantly increased and physical activity participation decreased (p-for-trends < 0.001). The findings suggest there is a need for targeted programs to decrease unhealthy weight status and support physical activity opportunities for adolescents with autism spectrum disorder across the severity spectrum.

Bullying Perpetration and Victimization among Adolescents with Overweight and Obesity in a Nationally Representative Sample.

Background: Adolescents with obesity are more likely to experience bullying in comparison to their healthy weight peers. However, it is unclear whether adolescents with obesity are more likely to perpetuate bullying or be both, a bully perpetrator and a bully victim. The purpose of this analysis was to examine differences in bully perpetration, victimization, and both (perpetration and victimization) by BMI classification in a nationally representative sample of adolescents. Methods: Analyses included 31,770 adolescents, ages 10-17, from the combined 2016-2017 National Survey of Children's Health. Adolescents were grouped by BMI classification; outcome variables included bullying, difficulty making new friends, excessive arguing, depression, and behavioral conduct problems. Logistic regression models, adjusted for age, sex, race, household income, highest level of education in the household, and attention-deficit/hyperactivity disorder assessed the odds of each outcome comparing healthy weight to adolescents with overweight and obesity. Results: Adolescents with overweight and obesity had greater odds of experiencing bullying behaviors: bully victim [odds ratio (OR) = 1.34 and 2.03] and both bully perpetrator and victim (OR = 1.37 and 2.01) (p's < 0.05), respectively, in comparison to healthy weight peers. Adolescents with overweight or obesity involved in bullying behaviors had significantly higher odds of behavioral conduct problems, depression, arguing excessively, and having difficulty making friends compared to adolescents with overweight or obesity who were neither a bully perpetrator nor victim (p's < 0.05). Conclusions: To promote overall health and well-being among adolescents with overweight and obesity, effort should be made to mitigate engagement in and/or victimization from bullying and associated behavioral or depressive symptoms.

Impact of Prolonged Sitting on Peripheral and Central Vascular Health.

Prolonged, uninterrupted sitting negatively impacts markers of peripheral vascular health, particularly, vasodilatory function of leg arteries. Whether sitting can similarly impact measures of central vascular health, as well as overall leg vasoreactivity (i.e., vasodilatory and vasoconstrictor function) remains unknown. To address this, measurements were made in relatively healthy participants (i.e., free of overt disease; n = 20, age = 26 ± 7; body mass index = 30 ± 7 kg/m2; 7 female) pre, during and post 3 hours of uninterrupted sitting. Measures of central vascular health included arterial wave reflection (augmentation index and Reflection Magnitude-RM%) and aortic vascular stiffness (aortic pulse wave velocity). Local vasoreactivity of the distal, posterior tibial artery was measured using flow-mediated dilation-FMD, coupled with low-flow mediated constriction, and microvascular function was assessed through the total hyperemic blood velocity (area-under-curve) response during FMD. After sitting, there was a significant increase in aortic pulse wave velocity (pre sit = 5.7 ± 0.3 vs post sit = 6.1 ± 0.3 m/s; p = 0.009, d = 0.36), whereas, augmentation index decreased (pre sit = 13 ± 3 vs post sit = 3 ± 1%; p < 0.001, d = 0.71). Albeit a moderate effect for decrease, RM% was not significantly altered during sitting (p = 0.13, d = 0.3). Vasodilatory (i.e., FMD pre sit = 0.5 ± 0.04 vs post sit = 0.3 ± 0.04 mm; p = 0.014, d = 0.29) and microvascular function (i.e., Microvascular area-under-curve: pre sit = 2,196 ± 333 vs 1,157±172 AU; p = 0.003, d = 0.31) decreased, but vasoconstrictor function (low-flow mediated constriction; p = 0.85, d = 0.005) was unaffected by sitting. In conclusion, these data demonstrate that a prolonged bout of uninterrupted sitting negatively impacts markers of peripheral and central vascular health in relatively healthy adults.

Flourishing and academic engagement among adolescents with overweight and obesity.

BACKGROUND: Overweight and obesity in adolescence are associated with several negative health indicators; the association with flourishing, an indicator of overall well-being, is less clear. OBJECTIVES: To examine associations between weight status and indicators of flourishing and academic engagement in adolescents. SUBJECTS: Analyses included 22,078 adolescents (10-17 years) from the 2016 National Survey of Children's Health. METHODS: Adolescents were grouped according to body mass index (BMI) classification; outcomes included indicators of flourishing and academic engagement. Logistic regression models assessed the odds of each outcome comparing adolescents with overweight and adolescents with obesity to healthy weight adolescents. RESULTS: For flourishing, adolescents with overweight and adolescents with obesity were less likely to stay calm during a challenge (17% and 30%, respectively; p < 0.01); adolescents with obesity were 30% less likely to finish a task they started (p < 0.001), and 34% less likely to show interest in new things (p < 0.001) in comparison to healthy weight peers. Adolescents with obesity were 26% less likely to care about doing well in school (p < 0.001), and adolescents with overweight and adolescents with obesity were significantly less likely to complete all required homework (19% and 34%, respectively) (p < 0.001), in comparison to healthy weight peers. CONCLUSIONS: A comprehensive approach to addressing overweight and obesity in adolescence should target improving academic engagement and flourishing to promote overall well-being.

Comparison of Obesity, Physical Activity, and Sedentary Behaviors Between Adolescents With Autism Spectrum Disorders and Without.

Body mass index classification, physical activity (PA), and sedentary behaviors were compared in adolescents with autism spectrum disorder (ASD) to typically developing adolescents. Participants included 42,747 adolescents (ASD, n = 915) from the 2011-2012 National Survey of Children's Health. After controlling for covariates, adolescents were more likely to be overweight and obese, and less likely to engage in regular PA versus typically developing adolescents (p's < 0.05). Increased odds for overweight and obesity were attenuated after adjustment for PA. Higher autism severity was associated with increased odds of overweight and obesity and decreased odds of PA, sport, and club participation. These findings suggest adolescents with ASD are in need of targeted programs to decrease obesity and increase physical activity.

Effects on carotid-femoral pulse wave velocity 24 h post exercise in young healthy adults.

Arterial stiffness, often measured by carotid-femoral pulse wave velocity (cfPWV), is a subclinical marker of cardiovascular disease that is known to be reduced by exercise training. Exercise is also known to have acute vascular effects, yet it is unclear whether exercise 24 h before cfPWV testing influences this outcome. Thirty healthy, young adults completed a supervised, 30-min bout of moderate-to-vigorous intensity treadmill running. cfPWV, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were measured both before (after 48 h of abstaining from exercise) and 24 h after (with no additional exercise) the exercise session. From pre-exercise to 24 h post exercise, cfPWV decreased from 6.05±0.82 to 5.84±0.87 m s(-1) (P=0.02), SBP from 119.7±13.8 to 116.8±11.4 mm Hg (P=0.03) and DBP from 65.1±5.7 to 63.2±5.4 mm Hg (P=0.02), with no significant changes in HR. cfPWV was positively correlated with SBP pre-exercise (r=0.54, P<0.01) and post exercise (r=0.53, P<0.01). Changes in blood pressure explained 4-5% of the variability in cfPWV change; adjustments slightly attenuated the 24-h effects of exercise on cfPWV. Some evidence of gender differences was observed with higher cfPWV in males across assessments (P<0.05) and statistically significant reductions in cfPWV in males (-0.36±0.54 m s(-1) (P=0.02)) but not in females (-0.07±0.31 m s(-1) (P=0.41)). In conclusion, cfPWV decreased 24 h after an exercise bout, suggesting that exercise completed in the past 24 h should be considered before cfPWV testing.