1. Lifestyle behaviors and cardiometabolic disease

Background: Beneficial 24-hour activity behaviors (i.e., limiting sedentary behavior, physical activity, sleep) are critical for chronic disease prevention, but were altered by the COVID-19 pandemic. Less time in beneficial 24-hour activity behaviors may place individuals at greater risk for contracting COVID-19. Further, some populations may be more impacted than others, with demographic and environmental (rural/urban/suburban) factors influencing access to healthcare and COVID-19 information. Methods: In December 2020, we recruited an online convenience sample of 746 adults aged 18 years or older residing in the US. Of the sample, 400 (39±14 years old, 52% female, 15% Hispanic, 78% White, and 28% had or survived cancer) had complete data for our variables of interest. Participants self-reported demographic information, COVID-19 diagnosis (yes/no), total weekday and weekend sedentary behavior (hours/day), moderate to vigorous physical activity (mins per week), sleep (hours/day), and environment (rural/urban/suburban). a) A k-fold cross-validation, machine learning variable selection (glmnet) approach was used to identify which variables were most strongly associated with COVID-19 prevalence, as determined by specifying the tuning parameter, λ, at its minimum value. This approach minimizes the elastic net penalty and optimizes the model fit. b) Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95%CI) for the strongly associated variables. Results: a) The variables most associated with COVID-19 prevalence were total sedentary behavior during weekdays, sleep, biological sex, race, and environment (λ=0.012). b) Holding all other parameters constant, the odds of having COVID-19 were lower for every additional hour of sleep (OR=0.87, 95%CI=0.79, 0.96); identifying as non-white versus white (OR=0.46, 95%CI=0.23, 0.87); living in a rural versus urban area (OR=0.42, 95%CI=0.18, 0.92); and higher for being male versus female (OR=2.79, 95%CI=1.69, 4.67). Non-significant decreases were found for weekday sedentary behavior (OR=0.97; 95%CI=0.92, 1.02) and living in a suburban versus urban areas (OR=0.63, 95%CI=0.38, 1.05). Conclusion: Less sleep, identifying as non-white, female, and residing in rural areas were associated with a lower COVID-19 prevalence.

Endometrial cancer survivors experience high rates of cardiovascular disease (e.g., heart disease, obesity, diabetes). The heightened cardiovascular disease risk may be attributed to cancer treatment coupled with sub-optimal lifestyle behaviors following treatment, including high amounts of sedentary behavior (SB). Public health agencies have graded the association of evidence between SB and cardiovascular disease as strong. However, while clinicians may wish to prescribe SB substitution strategies to reduce SB, guidelines do not currently exist. An additional challenge to behavior change pertains to the unique barriers that endometrial cancer survivors face, including treatment-associated fatigue and limited self-efficacy. Engaging in healthy movement behaviors, including minimizing SB and achieving recommended amounts of physical activity, are critical for health and well-being as well as cardiometabolic disease prevention. The purpose of this perspective paper is to propose an informed approach to physical activity promotion aimed to initiate movement and promote long-term behavior change by starting with an emphasis on reducing SB in endometrial cancer survivors. First, we address why endometrial cancer survivors should be targeted with SB reduction. Then, we suggest a stepwise approach to increasing physical activity by starting with SB reduction, including consideration to behavioral theories. Finally, we provide suggestions for future directions.

Aim Exercise training with blood flow restriction (BFR) increases muscle size and strength. However, there is limited investigation into the effects of BFR on cardiovascular health, particularly central hemodynamic load. Purpose To determine the effects of BFR exercise on central hemodynamic load (heart rate—HR, central pressures, arterial wave reflection, and aortic stiffness). Methods Fifteen males (age = 25 ± 2 years; BMI = 27 ± 2 kg/m², handgrip max voluntary contraction-MVC = 50 ± 2 kg) underwent 5-min bouts (counter-balanced, 10 min rest between) of rhythmic unilateral handgrip (1 s squeeze, 2 s relax) performed with a moderate-load (60% MVC) with and without BFR (i.e., 71 ± 5% arterial inflow flow reduction, assessed via Doppler ultrasound), and also with a low-load (40% MVC) with BFR. Outcomes included HR, central mean arterial pressure (cMAP), arterial wave reflection (augmentation index, AIx; wave reflection magnitude, RM%), aortic arterial stiffness (pulse wave velocity, aPWV), and peripheral (vastus lateralis) microcirculatory response (tissue saturation index, TSI%). Results HR increased above baseline and time control for all handgrip bouts, but was similar between the moderate load with and without BFR conditions (moderate-load with BFR = + 9 ± 2; moderate-load without BFR = + 8 ± 2 bpm, p < 0.001). A similar finding was noted for central pressure (e.g., moderate load with BFR, cMAP = + 14 ± 1 mmHg, p < 0.001). No change occurred for RM% or AIx (p > 0.05) for any testing stage. TSI% increased during the moderate-load conditions (p = 0.01), and aPWV increased above baseline following moderate-load handgrip with BFR only (p = 0.012). Conclusions Combined with BFR, moderate load handgrip training with BFR does not significantly augment central hemodynamic load during handgrip exercise in young healthy men.

Prolonged uninterrupted sitting and a typical Western meal, high in fat and refined sugar, can additively impair cognitive and cerebrovascular functions. However, it is unknown whether interrupting these behaviours, with a simple desk-based activity, can attenuate the impairment. The aim of this study was to determine whether regular leg fidgeting can off-set the detrimental effects of prolonged sitting following the consumption of a typical Western meal, on executive and cerebrovascular function. Using a randomized cross-over design, 13 healthy males consumed a Western meal and completed 180-min of prolonged sitting with leg fidgeting of 1 min on/4 min off (intervention [INT]) and without (control [CON]). Cognitive function was assessed pre and post sitting using the Trail Maker Test (TMT) parts A and B. Common carotid artery (CCA) blood flow, as an index of brain flow, was measured pre and post, and cerebral (FP1) perfusion was measured continuously. For TMT B the CON trial significantly increased (worsened) completion time (mean difference [MD] = 5.2 s, d = 0.38), the number of errors (MD = 3.33, d = 0.68) and cognitive fatigue (MD = 0.73, d = 0.92). Compared to CON, the INT trial significantly improved completion time (MD = 2.3 s, d = 0.97), and prevented declines in cognitive fatigue and a reduction in the number of errors. No significant changes in cerebral perfusion or CCA blood flow were found. Leg fidgeting for 1-min on/4-min off following a meal high in fats and refined sugars attenuated the impairment in executive function. This attenuation in executive function may not be caused by alterations in CCA blood flow or cerebral perfusion.

Objective: Childhood cardiometabolic disease risk (CMD) has been associated with short sleep duration. Its relationship with other aspects of sleep should also be considered, including social jetlag (SJL) which represents the difference between a person's social rhythms and circadian clock. This study investigated whether childhood CMD risk is associated with sleep duration, sleep disturbances, and SJL. Study Design: The observational study included 332 children aged 8–10 years (48.5% female). The three independent variables were sleep duration, sleep disturbances, and SJL. SJL was calculated as the variation in hours between the midpoint of sleep during free (weekend) days and work/school days. Eleven cardiometabolic biomarkers were measured, including central blood pressure, lipids, glycated hemoglobin, arterial wave reflection, and glucose. Underlying CMD risk factors were identified using factor analysis. Results: Four underlying CMD risk factors were identified using factor analysis: blood pressure, cholesterol, vascular health, and carbohydrate metabolism. Neither sleep disturbances nor sleep duration were significantly associated with any of the four CMD factors following adjustments to potential confounders. However, SJL was significantly linked to vascular health ( p = 0.027) and cholesterol ( p = 0.025). Conclusion: These findings suggest that SJL may be a significant and measurable public health target for offsetting negative CMD trajectories in children. Further studies are required to determine biological plausibility.

The purpose of this study was to determine how subconcussive head impact exposure in high school collision sport student-athletes influenced cerebrovascular function. Transcranial Doppler was used to assess pre- to post-season changes in: (1) resting middle (MCA) and posterior cerebral arteries (PCA), (2) cerebrovascular reactivity (CVR) via breath-holding index (BHI), vasomotor reactivity response (VMRr) and overall MCA response curve, and (3) neurovascular coupling (NVC) via NVC response magnitude and overall PCA response curve. Fifty-three high school-aged athletes (age = 15.8 ± 1.2years, height = 175.8 ± 8.1cm, mass = 69.4 ± 13.5kg) were recruited into two groups (collision vs. non-collision sport). All participants completed a pre-season cerebrovascular function assessment. Following a 4- to 5-month window (118.6 ± 12.2 days), 48 athletes from the original sample (age = 16.0 ± 1.2 years, height = 175.5 ± 8.1 cm, mass = 68.6 ± 4.0 kg) repeated the cerebrovascular assessment. There were no group differences in any cerebrovascular measures at pre-season testing (p > 0.05). At post-season testing, collision sport athletes demonstrated greater positive change in BHI (t44 = -2.21, p = 0.03) while non-collision sport athletes demonstrated greater negative change in the NVC response magnitude to the reading task (t44 = 1.98, p = 0.048), and lower overall PCA response curve to the reading task (F1,2710 = 101.54, p < 0.001). All other pre- to post-season change values were non-significant (p > 0.05). Our data indicate that single-season changes in cerebrovascular outcomes may differ between collision and non-collision sport athletes. Although the clinical interpretation is still unclear, our study demonstrates that CVR and NVC assessments may be sensitive to the dynamic cerebrovascular changes occurring in adolescent athletes. Future research should continue to assess these outcomes following both subconcussive head impact exposure and throughout the recovery trajectory following concussion.

Objectives To examine the relationships among self-reported sport-related concussion (SRC) history and current health-promoting behaviours (exercise frequency, diet quality and sleep duration) with self-reported measures of brain health (cognitive function, symptoms of depression and anxiety and emotional–behavioural dyscontrol) in former NFL players. Methods In this cross-sectional study, a questionnaire was sent to former NFL players. Respondents reported SRC history (categorical: 0; 1–2; 3–5; 6–9; 10+ concussions), number of moderate-to-vigorous aerobic and resistance exercise sessions per week, diet quality (Rapid Eating Assessment for Participants—Shortened) and average nightly sleep duration. Outcomes were Patient-Reported Outcomes Measurement Information System Cognitive Function, Depression, and Anxiety, and Neuro-QoL Emotional-Behavioral Dyscontrol domain T-scores. Multivariable linear regression models were fit for each outcome with SRC history, exercise frequency, diet quality and sleep duration as explanatory variables alongside select covariates. Results Multivariable regression models (n=1784) explained approximately 33%–38% of the variance in each outcome. For all outcomes, SRC history (0.144≤|β|≤0.217) was associated with poorer functioning, while exercise frequency (0.064≤|β|≤0.088) and diet quality (0.057≤|β|≤0.086) were associated with better functioning. Sleeping under 6 hours per night (0.061≤|β|≤0.093) was associated with worse depressive symptoms, anxiety and emotional–behavioural dyscontrol. Conclusion Several variables appear to be associated with mood and perceived cognitive function in former NFL players. SRC history is non-modifiable in former athletes; however, the effects of increasing postplaying career exercise frequency, making dietary improvements, and obtaining adequate sleep represent important potential opportunities for preventative and therapeutic interventions.

Behavioral theories inform the development of lifestyle interventions to address low participation in physical activity (PA); however, relatively little is known about the value of self-determination theory (SDT) for explaining screen time (ST) behaviors or in extending SDT into a dyadic context. Actor-partner (i.e., parent-adolescent) interdependence models (APIMs) allow for examination of these interpersonal relationships. The purpose of this study was to examine PA and ST among parent-adolescent dyads using the cross-sectional Family Life, Activity, Sun, Health, and Eating (FLASHE) Study. Parent-adolescent dyads provided responses to online surveys addressing PA (n = 1177 dyads) and ST (n = 1489 dyads) behaviors. We examined the influence of SDT-based constructs (perceived competence and motivation) on PA and ST behaviors. Structural equations were used to estimate APIMs in STATA 15.1. Full models provided a good fit to the data. For both PA and ST, perceived competence was more strongly associated with motivation among adolescents compared with parents (PA: β = 0.72 vs. 0.58, ST: β = 0.34 vs. 0.22, p's < 0.001). Parental motivation was associated with parental PA and both adolescent motivation for PA and ST (p's < 0.001). Parental motivation was not associated with adolescent ST-behavior. Adolescent motivation was only associated with parent motivation for PA. In the FLASHE study, SDT constructs extend acceptably to the dyadic setting, with PA models providing a slightly better fit to the data than ST models. Longitudinal studies that target perceived competence and the self-regulation of motivation in parents and their adolescents are a next logical step to understanding both PA and ST behaviors.

Introduction Social jetlag has been reported to predict obesity-related indices, independent of sleep duration, with associations in female adolescents but not males. However, such sex-specific relationships have not been investigated in pre-adolescents. Objectives To examine: (i) the relationships between sleep characteristics, including social jetlag, and obesity-related outcomes during childhood, and (ii) whether these relationships are moderated by sex. Methods This cross-sectional study included 381 children aged 9-11 years (49.6% female). Average sleep duration, social jetlag, and physical activity were assessed via wrist-worn accelerometry. Sleep disturbances were quantified from the Children's Sleep Habits Questionnaire. Obesity-related outcomes included age-specific body mass index Z-scores (zBMI) and waist-to-height ratio. Additionally % fat, total fat mass, and fat mass index were assessed via bioelectrical impedance analysis. Linear mixed models that nested children within schools were used to identify relationships among sleep characteristics and obesity-related outcomes. Results Positive associations between social jetlag with zBMI, % fat, and fat mass index were seen in univariable and unadjusted multivariable analyses. Following adjustments for known confounders, social jetlag remained significantly associated with zBMI (β = 0.12, p = 0.013). Simple slopes suggested a positive association in girls (β = 0.19, p = 0.006) but not in boys (β = 0.03, p = 0.703). Conclusions Obesity prevention efforts, particularly in girls, may benefit from targeted approaches to improving the consistency of sleep timing in youth.

Cardiorespiratory fitness (CRF) is now an established vital sign. CRF, along with muscle function and bone and joint health is related to functional independence and a higher quality of life. Wasserman and colleagues proposed a gear model illustrating the integrated role of the respiratory, cardiovascular, and skeletal muscle systems during aerobic exercise; in 2015, a revision to the original model was proposed. Our understanding of the effects and challenges associated with the coronavirus disease 2019 (COVID-19) are rapidly evolving. Initial evidence indicates higher levels of CRF, and muscle function protect individuals infected with COVID-19 from a complicated medical course. Moreover, for those individuals infected with COVID-19, there are initial signs of a reduction in CRF following the initial phase of recovery. We are also gaining an understanding of long COVID syndrome, where individuals who have recovered from the acute phase of viral infection present with lasting symptoms, which include but are not limited to reduced CRF, shortness of breath, and fatigue. Clearly, these individuals will require rehabilitation to restore and/or improve CRF, muscle function, bone and joint health, functional capacity (ie, the ability to perform activities of daily living), and quality of life. The importance of assessing the synergistic function of systems essential to performing activities that require physical exertion is a health care imperative. This graphical narrative provides an update to the gear model initially proposed by Wasserman and updated to a gear and circuit in 2015. External CRF, muscle function, and bone and joint health influencers and an approach to clinical assessment are also introduced.

Background: Evidence for exercise as an efficacious strategy to improve aerobic capacity of breast cancer survivors (BCS) has come largely from intervention studies conducted in laboratory settings. There is an increasing need to translate to community-type settings, but the efficacy of those interventions using gold standard evaluation is not well-established. Aim: To investigate whether similar improvement in aerobic capacity (maximal oxygen consumption [VO2]) measured with gold standard testing can be achieved through a community-based setting in BCS. Methods: A peak cardiopulmonary exercise test (VO2peak), 6-min walk test (6MWT), and timed up and go test (TUG) were assessed pre- and post-16 wk of progressive intensity aerobic and strength training exercise at a community center. Results: The sample consisted of 31 early BCS (< 1 year since treatment completion) and 15 controls (CTLs). Both groups significantly improved VO2peak (+1.2 mL/kg/min; P = 0.030), 6MWT (+35 meters; P < 0.001), and TUG (-0.44 s; P < 0.01) following training. Both groups improved peak cycling power during the cardiopulmonary exercise test with BCS improving by +10 watts more than the CTLs (P = 0.020). Average exercise attendance was 71% (34 of 48 possible days), but compliant days averaged only 60% of total days for aerobic, and < 40% for strength in both groups. Conclusion: Community-based exercise programs can be an effective strategy to improve aerobic capacity and physical function for early-stage BCS but potentially not to the same extent observed in laboratory-based randomized controlled trials. Further research is needed to explore barriers and facilitators of exercise engagement in community-based centers to maximize training benefits for adults with cancer.

Objectives To assess the effect of a home-based over-ground robotic-assisted gait training program using the AlterG Bionic Leg orthosis on clinical functional outcomes in people with chronic stroke. Design Randomized controlled trial. Setting Home. Participants Thirty-four ambulatory chronic stroke patients who recieve usual physiotherapy. Intervention Usual physiotherapy plus either (1)10-week over-ground robotic-assisted gait training program ( n = 16), using the device for ⩾30 minutes per day, or (2) control group ( n = 18), 30 minutes of physical activity per day. Measurements The primary outcome was the Six-Minute Walk Test. Secondary outcomes included: Timed-Up-and-Go, Functional Ambulation Categories, Dynamic Gait Index and Berg Balance Scale. Physical activity and sedentary time were assessed using accelerometry. All measurements were completed at baseline, 10 and 22 weeks after baseline. Results Significant increases in walking distance were observed for the Six-Minute Walk Test between baseline and 10 weeks for over-ground robotic-assisted gait training (135 ± 81 m vs 158 ± 93 m, respectively; P ⩽ 0.001) but not for control (122 ± 92 m vs 119 ± 84 m, respectively). Findings were similar for Functional Ambulation Categories, Dynamic Gait Index and Berg Balance Scale (all P ⩽ 0.01). For over-ground robotic-assisted gait training, there were increases in time spent stepping, number of steps taken, number of sit-to-stand transitions, and reductions in time spent sitting/supine between baseline and 10 weeks (all P < 0.05). The differences observed in all of the aforementioned outcome measures were maintained at 22 weeks, 12 weeks after completing the intervention (all P > 0.05). Conclusion Over-ground robotic-assisted gait training combined with physiotherapy in chronic stroke patients led to significant improvements in clinical functional outcomes and physical activity compared to the control group. Improvements were maintained at 22 weeks.

Skeletal muscle microvascular dysfunction and mitochondrial rarefaction feature in type 2 diabetes mellitus (T2DM) linked to low tissue glucose disposal rate (GDR). Exercise training and milk protein supplementation independently promote microvascular and metabolic plasticity in muscle associated with improved nutrient delivery, but combined effects are unknown. In a randomised-controlled trial, 24 men (55.6 y, SD 5.7) with T2DM ingested whey protein drinks (protein/carbohydrate/fat: 20/10/3 g; WHEY) or placebo (carbohydrate/fat: 30/3 g; CON) before/after 45 mixed-mode intense exercise sessions over 10 weeks, to study effects on insulin-stimulated (hyperinsulinemic clamp) skeletal-muscle microvascular blood flow (mBF) and perfusion (near-infrared spectroscopy), and histological, genetic, and biochemical markers (biopsy) of microvascular and mitochondrial plasticity. WHEY enhanced insulin-stimulated perfusion (WHEY-CON 5.6%; 90% CI −0.1, 11.3), while mBF was not altered (3.5%; −17.5, 24.5); perfusion, but not mBF, associated (regression) with increased GDR. Exercise training increased mitochondrial (range of means: 40%–90%) and lipid density (20%–30%), enzyme activity (20%–70%), capillary:fibre ratio (∼25%), and lowered systolic (∼4%) and diastolic (4%–5%) blood pressure, but without WHEY effects. WHEY dampened PGC1α −2.9% (90% compatibility interval: −5.7, −0.2) and NOS3 −6.4% (−1.4, −0.2) expression, but other messenger RNA (mRNA) were unclear. Skeletal muscle microvascular and mitochondrial exercise adaptations were not accentuated by whey protein ingestion in men with T2DM. ANZCTR Registration Number: ACTRN12614001197628. Novelty: Chronic whey ingestion in T2DM with exercise altered expression of several mitochondrial and angiogenic mRNA. Whey added no additional benefit to muscle microvascular or mitochondrial adaptations to exercise. Insulin-stimulated perfusion increased with whey but was without impact on glucose disposal.

Regular exposure to uninterrupted prolonged sitting and the consumption of high glycemic meals (HGI) is independently associated with increased cardiovascular disease risk. Sitting for as little as 1-hour can impair the health of both peripheral and central arteries. However, it is currently unknown whether combined acute exposure to uninterrupted prolonged sitting and a HGI meal is more detrimental to global (peripheral and central) vascular health. The purpose of this study was to investigate the effect of prolonged sitting (3 hours), following the consumption of a HGI or low glycemic index (LGI) meal, on global pulse wave velocity (G-PWV). Methods: Eighteen healthy participants (70% female, mean standard deviation [SD] age: 22.6 [3.1] years old, BMI: 25.5 [6.1] kg/m2) sat for 3 hours after consuming a HGI or LGI meal. G-PWV was assessed by incorporating three PWV measures (carotid-femoral, brachial-femoral, femoral-ankle). The effects of time (PRE vs. POST) and condition (LGI vs. HGI) were analyzed using linear mixed models. Results: Following prolonged sitting, G-PWV increased by 0.29 m/s (i.e., PRE vs. POST). However, the condition (P=0.987) and time x condition (P=0.954) effects were non-significant. Discussion: The current findings support previous research showing an increase in arterial stiffness with prolonged sitting. However, in young and healthy adults, the arterial stiffness response was not worsened through HGI consumption.

COVID-19 is one of the biggest health crises that the world has seen. Whilst measures to abate transmission and infection are ongoing, there continues to be growing numbers of patients requiring chronic support, which is already putting a strain on health care systems around the world and which may do so for years to come. A legacy of COVID-19 will be a long-term requirement to support patients with dedicated rehabilitation and support services. With many clinical settings characterized by a lack of funding and resources, the need to provide these additional services could overwhelm clinical capacity. This position statement from the Healthy Living for Pandemic Event Protection (HL-PIVOT) Network provides a collaborative blueprint focused on leading research and developing clinical guidelines, bringing together professionals with expertise in clinical services and the exercise sciences to develop the evidence base needed to improve outcomes for patients infected by COVID-19.

Background Cardiovascular disease (CVD) risk increases substantially during perimenopause. Latinas have a significantly worse CVD risk factor profile than non-Hispanic White women, potentially due to multiple sociocultural and environmental factors. To date, interdisciplinary interventions have not focused on improving nutrition, physical activity, stress management, and biologic CVD risk in perimenopausal Latinas. The purpose of this study is to examine the feasibility and initial efficacy of a multi-component intervention to reduce CVD risk in perimenopausal Latinas. Methods This is a two-group, repeated measures experimental study. Eighty perimenopausal Latinas (age 40–55 years) from two community groups will be randomized: one group will complete the intervention; the other will be a wait-list control. The intervention consists of 12-weekly sessions (education, physical activity, stress management, coping skills training), followed by 3 months of continued support, and 6 months of skill maintenance on their own. The primary outcomes include arterial stiffness, blood pressure, lipids, and blood glucose. Secondary outcomes are health behaviors (nutrition, physical activity, sleep, coping strategies), self-efficacy, and other biological factors related to CVD risk (adiposity, C-reactive protein, hair cortisol, vasomotor symptoms). We will assess changes in outcomes from Time 1 (baseline) to Time 2 (6 months) and Time 3 (12 months) using general linear mixed models to test the hypotheses. We will also evaluate the feasibility of the intervention by assessing enrollment and retention rates, barriers, and facilitators to enrollment, intervention fidelity, the suitability of study procedures, and participant satisfaction with the intervention and study protocol. We hypothesize the intervention group will decrease biologic CVD risk and improve health behaviors and self-efficacy significantly more than the wait-list control. Discussion Results from this study will contribute to knowledge on the feasibility of behavioral interventions, including stress management and coping skills training, which could reduce CVD burden among perimenopausal Latinas. Because Hispanic/Latinos are the largest ethnic minority in the United States (US), progress regarding CVD risk among perimenopausal Latinas may lead to significant improvement in the overall CVD burden in the US. Trial registration Prospectively registered, NCT04313751 (03/19/2020), Protocol version 1.0

Cite Stanford, Kathleen1; Pomeroy, Alexander1; Bates, Lauren C.1; Tamminga, Kyle2; Chai, Thevy2; Moore, Justin B.3; Brookey, Lindsay4; Stoner, Lee1 Exercise Is Medicine® on Campus during COVID-19: Necessary Adaptations and Continuing Importance, Translational Journal of the ACSM: Fall 2020 - Volume 5 - Issue 12 - e000157 d

Objectives: To assess how the early stages of National governments Coronavirus disease (COVID-19) containment strategies impacted upon the physical activity, mental health and well-being of adults in the UK, Ireland, New Zealand and Australia Design: Observational, cross-sectional Setting: Online survey disseminated in the UK, Ireland, New Zealand and Australia within the first 2-6 weeks of government mandated COVID-19 restrictions Participants: Adults (n = 8,425; 44.5 [14.8] y), ≥ 18 y who were residing in the surveyed countries Main outcome measures: Stages of Change scale for exercise behaviour change, International Physical Activity Questionnaire (short-form), World Health Organisation-5 Well-being Index and the Depression Anxiety and Stress Scale-9 Results: Participants who reported a negative change in exercise behaviour between pre- and during the early COVID-19 restrictions demonstrated poorer mental health and well-being compared to those who had either a positive change- or no change in their exercise behaviour (p<0.001). Whilst women reported more positive changes in exercise behaviour, young people (18-29y) reported more negative changes (both p<0.001). Individuals who engaged in more physical activity reported better mental health and well-being (p<0.001). Although there were no differences in physical activity between countries, individuals in New Zealand reported better mental health and well-being (p<0.001). Conclusion: The COVID-19 restrictions have differentially impacted upon the physical activity habits of individuals based upon their age and sex, and therefore have important implications for international policy and guideline recommendations. Public health interventions that encourage physical activity should target specific groups (e.g., men, young adults) who are most vulnerable to the negative effects of physical distancing and/or self-isolation.

Introduction Cardiorespiratory fitness (CRF) is a vital sign that can improve risk classification for adverse health outcomes. While lifestyle-related factors are associated with CRF, few have examined the influence of sleep characteristics, especially in youths. Social jetlag, a mismatch between one’s biological clock and sleep schedule, is prevalent in adolescents and associated with increased adiposity, though its relationship with CRF is unclear. Objective To quantify the relationship between social jetlag and CRF, independent of other sleep characteristics. Methods This cross-sectional sample includes 276 New Zealand adolescents (14-18 years, 52.5% female). CRF (VO2max) was estimated from a 20-meter multi-stage shuttle run. Average sleep duration, sleep disturbances, social jetlag, physical activity, and the number of bedroom screens were estimated from validated self-report surveys. Social jetlag is the difference in hours between the midpoint of sleep during weekdays (school) and weekend days (free). Combined and sex-stratified linear regression assessed the association between sleep outcomes and CRF, controlling for relevant covariates. Results Males slept 17.6 minutes less, had less sleep disturbances, and a 25.1-minute greater social jetlag than their female peers (all p<.05). A one-hour increase in social jetlag was associated with a 0.72 ml/kg/min decrease in VO2max (95%CI: -1.31, -0.14), independent of other sleep variables, which were not associated with CRF. Sex-specific models indicated an association in males (B -0.93, 95%CI: -1.76, -0.09), but not females (B -0.32, 95%CI: -1.18, 0.55). Conclusions Social jetlag is negatively associated with CRF in adolescent males and may be a simple, measurable target for public health interventions.

Background Exposure to acute prolonged sitting can result in vascular dysfunction, particularly within the legs. This vascular dysfunction, assessed using flow-mediated dilation (FMD), is likely the consequence of decreased blood flow-induced shear stress. With mixed success, several sitting interruption strategies have been trialled to preserve vascular function.Objectives The objectives of this meta-analysis were to (1) assess the effects of acute prolonged sitting exposure on vascular function in the upper- and lower-limb arteries, and (2) evaluate the effectiveness of sitting interruption strategies in preserving vascular function. Sub-group analyses were conducted to determine whether artery location or interruption modality explain heterogeneity.Data SourcesElectronic databases (PubMed, Web of Science, SPORTDiscus, and Google Scholar) were searched from inception to January 2020. Reference lists of eligible studies and relevant reviews were also checked.Study SelectionInclusion criteria for objective (1) were: (i) FMD% was assessed pre- and post-sitting; (ii) studies were either randomised-controlled, randomised-crossover, or quasi-experimental trials; (iii) the sitting period was ≥ 1 h; and (iv) participants were healthy non-smoking adults (≥ 18 years), and free of vascular-acting medication and disease at the time of testing. Additional inclusion criteria for objective (2) were: (i) the interruption strategy must have been during the sitting period; (ii) there was a control (uninterrupted sitting) group/arm; and (iii) the interruption strategy must have involved the participants actively moving their lower- or upper-limbs.Appraisal and Synthesis Methods One thousand eight hundred and two articles were identified, of which 17 (22 trials, n = 269) met inclusion criteria for objective (1). Of those 17 articles, 6 studies (9 trials, n = 127) met the inclusion criteria for objective (2). Weighted mean differences (WMD), 95% confidence intervals (95% CI), and standardised mean difference (SMD) were calculated for all trials using random-effects meta-analysis modelling. SMD was used to determine the magnitude of effect, where < 0.2, 0.2, 0.5, and 0.8 was defined as trivial, small, moderate, and large respectively.Results(1) Random-effects modelling showed uninterrupted bouts of prolonged sitting resulted in a significant decrease in FMD% (WMD = − 2.12%, 95% CI − 2.66 to − 1.59, SMD = 0.84). Subgroup analysis revealed reductions in lower- but not upper-limb FMD%. (2) Random-effects modelling showed that interrupting bouts of sitting resulted in a significantly higher FMD% compared to uninterrupted sitting (WMD = 1.91%, 95% CI 0.40 to 3.42, SMD = 0.57). Subgroup analyses failed to identify an optimum interruption strategy but revealed moderate non-significant effects for aerobic interventions (WMD = 2.17%, 95% CI − 0.34 to 4.67, SMD = 0.69) and simple resistance activities (WMD = 2.40%, 95% CI − 0.08 to 4.88, SMD = 0.55) and a trivial effect for standing interruptions (WMD = 0.24%, 95% CI − 0.90 to 1.38, SMD = 0.16).Conclusions Exposure to acute prolonged sitting leads to significant vascular dysfunction in arteries of the lower, but not upper, limbs. The limited available data indicate that vascular dysfunction can be prevented by regularly interrupting sitting, particularly with aerobic or simple resistance activities.

Arterial stiffness is an important marker of vascular damage and a strong predictor of cardiovascular diseases (CVD). Given that pathophysiological processes leading to an increased arterial stiffness begin during childhood, the aim of this clustered observational study was to determine the relationship between modifiable factors including dietary patterns and indices of aortic arterial stiffness and wave reflection in 9–11-year-old children. Data collection was conducted between April and December 2015 in 17 primary schools in Dunedin, New Zealand. Dietary data were collected using a previously validated food frequency questionnaire and identified using principal component analysis method. Arterial stiffness (carotid-femoral pulse wave velocity, PWV) and central arterial wave reflection (augmentation index, AIx) were measured using the SphygmoCor XCEL system (Atcor Medical, Sydney, Australia). Complete data for PWV and AIx analyses were available for 389 and 337 children, respectively. The mean age of children was 9.7 ± 0.7 years, 49.0% were girls and 76.0% were classified as “normal weight”. The two identified dietary patterns were “Snacks” and “Fruit and Vegetables”. Mean PWV and AIx were 5.8 ± 0.8 m/s and −2.1 ± 14.1%, respectively. There were no clinically meaningful relationships between the identified dietary pattern scores and either PWV or AIx in 9–11-year-old children.

New findings: What is the central question of this study? Prolonged sitting increases risk for cardiovascular disease, but the cellular and molecular determinants remain unknown. What is the main finding and its importance? Prolonged sitting, independent of calf raise interruption strategies, decreases MP counts linked to endothelial activation and apoptosis. An acute bout of prolonged sitting appears to promote paradoxical decreases in microparticle counts, but the implications are not yet clear. Abstract: Repeated exposure to prolonged sitting increases the risk for cardiovascular disease. However, the cellular links by which repeated exposure to prolonged sitting lead to increased cardiovascular risk have not been fully elucidated, with markers of vascular damage and repair such as microparticles (MP) and circulating angiogenic cell (CAC) being promising targets. Purpose To examine the effects of 3 h of sitting with or without intermittent calf raises on Annexin V+ /CD34+ , Annexin V+ /CD62E+ , and Annexin V+ /CD31+ /42b- MP populations linked to CAC paracrine activity, endothelial activation, and apoptosis, respectively, as well as CD14+ /31+ , CD3+ /31+ , and CD34+ CACs which are linked to endothelial repair. Methods In a random order, 20 sedentary participants (14 females, 22 ± 3 years) remained seated for 180 minutes with or without performing 10 calf raises every 10 minutes. Blood samples were obtained after 20 minutes of quiet rest in the supine position before and after sitting. Results Overall, sitting decreased Annexin V+ /CD34+ MPs (-12 ± 5 events/μl, P < 0.01), Annexin V+ /CD62E+ MPs (-17 ± 4 events/μl, P < 0.001), and Annexin V+ /CD31+ /42b- MPs (-22 ± 6 events/μl, P < 0.001) regardless of condition. There were no differences in endothelin-1 plasma concentration, CD14+ /31+ , CD34+ or CD3+ /31+ CAC frequencies. Conclusion Sitting did not alter CAC number, but decreased MPs linked to endothelial activation, apoptosis and CAC paracrine activity in a manner that was independent of muscle contraction. These findings support changes in markers of endothelial activation and apoptosis with sedentary behavior and provide new insights into altered intercellular communication with physical inactivity such as prolonged sitting. This article is protected by copyright. All rights reserved.

This meta‐analysis quantified the effect of FITT (Frequency, Intensity, Time and Type) manipulation on exercise adherence. Databases were searched from inception to 09‐2018. Manipulation of Intensity resulted in a moderate, significant decrease in adherence (MD: ‐3.3, 95% CI: ‐6.1 to ‐0.5), and for the remaining FITT components there were trivial‐small, non‐significant effects. When stratified by chronic disease status, for populations with chronic diseases increasing Intensity resulted in a moderate but non‐significant decrease in adherence (MD: ‐3.6, 95% CI: ‐7.4, 0.3) and increasing Time resulted in a small, significant decrease in exercise adherence (MD: ‐4.9, 95% CI: ‐9.4 to ‐0.4). Additionally, omission of a behavioral model resulted in a moderate but non‐significant decrease in exercise adherence (MD: ‐4.0, CI: ‐8.3 to 0.2). For healthy populations, FITT manipulation and omission of behavioral model resulted in trivial‐small, non‐significant effects. In conclusion, manipulation of FITT and use of behavioral models may be of greater importance to exercise adherence in diseased population. In particular, increasing Intensity and Time and omitting a behavioral model may decrease adherence. The current meta‐analysis elucidates gaps in the literature and can assist clinicians and clinical exercise physiologists in determining the importance of FITT manipulation to exercise adherence.

Few successful strategies address lifestyle and behavior change towards food and exercise among underserved children. Children spend the majority of their day in a school setting, providing an optimal environment to target behavior change with limited resources. Purpose This school-based pilot study was a collaborative effort among professionals from a state university, a county department of health, a county school system, and a nearby regional public hospital to improve knowledge, intentions, and self-efficacy about nutrition and physical activity among underserved children. Methods Thirty-three, fifth grade students were recruited from a low socioeconomic elementary school (Mean = 10.55 ± 0.56 years). Students were randomly assigned to a treatment (n = 19), or control group (n = 14) for 8 weeks. Once per week, the treatment group received 30 min of nutritional advice, and completed 30 min of functional exercises. Anthropometric and body composition assessments were made, and eating and physical activity behaviors were recorded using the CATCH Kids Club After-School Student Questionnaire at baseline, and at the end of week 8. A 2-way repeated-measure analysis of variance and paired-t tests with Bonferroni adjustments were used to analyze any differences. Results Physical activity, intentions, and knowledge for a healthy nutrition behavior increased significantly in the treatment group. However, causal inferences could not be made at this time. Conclusions This public sector partnership demonstrated that a simple school-based intervention can play a role in healthy choices among underserved children.

PurposeChildren require 9–11 h sleep to ensure adequate growth and development by optimizing the efficiency of a number of biological systems, including the cardiovascular system. The study aim was to determine whether short sleep duration (< 9 h) is associated with elevated aortic arterial stiffness in children aged 9–11 years, independent of other lifestyle behaviors, including physical activity, sedentary behaviour and dietary patterns.Methods This cross-sectional study included 421 children (51% female) aged 9–11 years. Aortic arterial stiffness was measured using carotid-femoral pulse wave velocity (cfPWV), sleep duration, time spent sedentary, and moderate-vigorous physical activity were measured using wrist actigraphy, and dietary patterns using a food frequency questionnaire. Associations between short sleep duration and cfPWV were examined using mixed effects regression.ResultsThere was a positive [unadjusted] association between short sleep duration and cfPWV (β = 0.245, 95% CI 0.093–0.396). This association persisted following adjustment for demographic factors and was strengthened following adjustment for lifestyle behaviors (β = 0.331, 95% CI 0.109–0.553).Conclusions Short sleepers (< 9 h) had a clinically meaningful elevated aortic arterial stiffness in comparison to those sleeping the recommended daily 9–11 h. Sleep duration may be important for cardiovascular health independent of other lifestyle behaviors.

Objective: Cardiovascular disease is the leading cause of death in breast cancer survivors. While evidence shows circuit resistance training (CRT) is effective for improving muscle and cardiorespiratory fitness, whether CRT is an efficacious therapy for decreasing cardiovascular risk in cancer survivors is unclear. Methods: Fifty-one breast cancer survivors were recruited to either 12 weeks CRT (n = 26), or a non-exercising wait-list control (n = 25). Two supervised 60 min CRT sessions per week were undertaken, comprising resistance and functional exercises, and aerobic exercise stations. Primary outcome measure was the gold-standard assessment of arterial stiffness, aortic pulse wave velocity (PWV). Secondary outcomes included: cardiorespiratory fitness (CRF), upper and lower body strength, arterial wave reflections, central blood pressure and rate pressure product. Results: Compared to the control group, the CRT group had a statistically significant medium effect decrease in PWV 0.9 m/s (95% CI: 0.1, 1.7). There were large effect improvements in VO2 max (4.3 ml kg-1 min-1 , 95% CI: 5.8, 2.8), upper and lower body strength (3.7 kg, 95% CI: 1.9, 5.6 and 10.4 kg, 1.6, 19.1) respectively. Conclusion: Findings support the existing literature demonstrating that 12 weeks CRT improves muscle and cardiorespiratory fitness and is also an effective strategy for decreasing a proven cardiovascular risk factor in breast cancer survivors.

Objective: To identify, in children the normal rate of carotid-femoral pulse wave velocity (cfPWV) progression, and whether presence of cardiometabolic risk factors is associated with cfPWV. Study design: Electronic databases (PubMed, Google Scholar) were searched from inception to May 2018, for all studies which reported cfPWV in children (<19 years of age). Random effects meta-regression quantified the association between time (years) and cfPWV, and a systematic review was performed to determine whether cardiometabolic risk factors are associated with cfPWV. Results: Data from 28 articles were eligible for inclusion, including 9 reference value (n = 13 100), 5 cardiovascular risk (n = 5257), 10 metabolic risk (n = 2999), and 8 obesity-focused (n = 8760) studies. Meta-regression findings (9 studies) showed that the increase in cfPWV per year (age) was 0.12 m/second (95% CI, 0.07-0.16 m/second) per year, and when stratified by sex the CIs overlapped. Systematic review findings showed that cardiometabolic risk factors were positively associated with cfPWV, including positive associations with blood pressure, impaired glucose metabolism, and metabolic syndrome. However, obesity was not consistently associated with cfPWV. Conclusions: Arterial stiffness in children progresses with age and is associated with cardiometabolic risk factors. Although further longitudinal studies are warranted, the presented reference data will be valuable to epidemiologists tracking children, and to scientists and clinicians prescribing therapies to mitigate risk in a population that is increasingly more vulnerable to cardiovascular disease.

Sedentary time (ST) has been inconsistently associated with adiposity and cardiorespiratory fitness in children in previous studies. We studied cross-sectional associations of ST, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with fat mass index (FMI) and cardiorespiratory fitness (estimated VO2max). Associations were evaluated with and without considering pattern of ST by bout length. We measured ST and activity by a wrist-worn accelerometer, FMI by bioelectrical impedance, and VO2max by Pacer test in 443 children (51.2% girls, 10.2 ± 0.6 years). Isotemporal substitution regression models estimated the effects of substituting ST, LPA, and MVPA on FMI and VO2max. Further models repeated analyses separating ST into short (<10 min) and long (≥10 min) bouts. Only replacing ST or LPA with MVPA was consistently associated with lower FMI and greater VO2max. When separated by bout length, only one unique association was found where replacing long ST bouts with short ST bouts was associated with lower FMI in girls only. In conclusion, activity pattern is associated with adiposity in girls and fitness in boys and girls. Separating ST into long and short ST bouts may be of minimal importance when assessing associations with adiposity and fitness using wrist-worn accelerometry in children.

Objective: To determine the associations between cardiorespiratory fitness (CRF) and fatness (overweight-obesity) with cardiometabolic disease risk among preadolescent children. Study design: This cross-sectional study recruited 392 children (50% female, 8-10 years of age). Overweight-obesity was classified according to 2007 World Health Organization criteria for body mass index. High CRF was categorized as a maximum oxygen uptake, determined using a shuttle run test, exceeding 35 mL·kg-1·minute-1 in girls and 42 mL·kg-1·minute-1 in boys. Eleven traditional and novel cardiometabolic risk factors were measured including lipids, glucose, glycated hemoglobin, peripheral and central blood pressure, and arterial wave reflection. Factor analysis identified underlying cardiometabolic disease risk factors and a cardiometabolic disease risk summary score. Two-way analysis of covariance determined the associations between CRF and fatness with cardiometabolic disease risk factors. Results: Factor analysis revealed four underlying factors: blood pressure, cholesterol, vascular health, and carbohydrate-metabolism. Only CRF was significantly (P = .001) associated with the blood pressure factor. Only fatness associated with vascular health (P = .010) and carbohydrate metabolism (P = .005) factors. For the cardiometabolic disease risk summary score, there was an interaction effect. High CRF was associated with decreased cardiometabolic disease risk in overweight-obese but not normal weight children (P = .006). Conversely, high fatness was associated with increased cardiometabolic disease risk in low fit but not high fit children (P < .001). Conclusions: In preadolescent children, CRF and fatness explain different components of cardiometabolic disease risk. However, high CRF may moderate the relationship between fatness and cardiometabolic disease risk. Trial registration: ACTRN 12614000433606.

Venepuncture is the established "gold standard" for sampling cortisol, but it is expensive, highly invasive and impractical for many experimental and clinical settings. Salivary free cortisol is a non-invasive and practical alternative; however, when cortisol concentrations exceed 500 nmol · L there is a lack of agreement between salivary (free) and venous (bound) cortisol. No known research has assessed whether capillary cortisol accurately reflects venous blood cortisol across a range of concentrations. The objective of the current study was to determine the agreement between capillary and venous blood samples of total plasma cortisol across a range of concentrations. 11 healthy male subjects (26.1±5.3 years) were recruited. Capillary and venous blood samples were collected pre and post (immediately post and post 5, 10, 15 and 20 min) a treadmill VO2max test. Regression analysis revealed a strong relationship (R2=0.96, y=1.0028x+1.2964 (P<0.05)) between capillary and venous cortisol concentrations. A Bland-Altman plot showed all data was within the upper and lower bounds of the 95% confidence interval, and no systematic bias was evident. In conclusion, capillary sampling is a valid technique for measuring bound cortisol across a range of concentrations.

This study assessed the effect of a short-term, 8-week exercise programme on resting and exercise blood pressure (systolic (SBP); diastolic (DBP)), and other haemodynamic responses (heart rate (HR), pulse pressure (PP), double product (DP)), of newly diagnosed transient ischaemic attack (TIA) patients. Sixty-eight TIA patients completed a continuous and incremental exercise test within 2 weeks of symptom diagnosis. HR, SBP and DBP were regularly measured at rest, during exercise and in recovery. Participants were then randomised to either an 8-week exercise programme or to a usual care control group prior to completing an identical post-intervention (PI) re-assessment. Individuals randomised to the exercise condition experienced a significantly greater reduction in resting HR (-5.4±10.2%), SBP (-6.7±8.1%) and DBP (-2.8±7.2%) than the control group at the PI assessment (all P<0.05). Similar findings were demonstrated at the PI assessment when comparing haemodynamic responses during exercise (P<0.05), with significantly larger decrements observed for SBP and HR (both 10-14%), PP (17-24%) and DP (26-32%) for those randomised to the exercise intervention (all P<0.05). This study demonstrates that structured physical activity soon after TIA diagnosis will improve haemodynamic responses. The early implementation of exercise following TIA diagnosis may be an important secondary prevention strategy for this population.Journal of Human Hypertension advance online publication, 30 May 2013; doi:10.1038/jhh.2013.43.