Effects of Exercise Interventions on Estimated Pulse Wave Velocity and Mean Arterial Pressure in Overweight Adults: The Role of Modality.

Background: Estimated pulse wave velocity (ePWV) is mathematically calculated from age and mean arterial pressure (MAP). We examined the effects of high-intensity interval training (HIIT) vs. moderate-intensity continuous training (MICT) on ePWV and MAP in insufficiently active overweight adults. Methods: Using the randomized controlled trial design, thirteen males (27.46 ± 3.80 years old; body mass index (BMI) = 29.61 ± 5.52) randomly completed either two-week HIIT (n = 7) or MICT (n = 6). HIIT consisted of 8 sessions of cycling, 20 min/session with an exercise-to-rest ratio of 10/50 s at ≥ 90% peak heart rate ( HR peak ). MICT consisted of 8 cycling sessions, 40 min/session at 60-75% HR peak . Oscillometric brachial MAP was measured pre- and post-intervention, and ePWV was calculated. Two-way repeated measure analysis of variance examined the effects of time, intervention, and their interactions on ePWV and MAP. Results: Significant time effects were observed for ePWV and MAP, where both measures comparably decreased over time in HIIT and MICT groups (p < 0.05 for all). However, no significant intervention or interaction effects were detected, indicating no superiority of either exercise modality for ePWV or MAP improvements. Conclusions: This study uniquely revealed that two weeks of HIIT or MICT resulted in significant, comparable, and clinically meaningful decreases in ePWV and MAP among insufficiently active overweight adults. As such, overweight adults who have time as a constraint to engage in traditional exercise (i.e., MICT) can accomplish comparable vascular benefits by performing HIIT.

Uninterrupted prolonged sitting and arterial stiffness: moderating effect of prior aerobic exercise in physically active adults.

PURPOSE: Prolonged sitting acutely increases arterial stiffness, with interruption strategies only providing limited success in offsetting these rises. Acute aerobic exercise is a potent stimulus to decrease arterial stiffness. However, limited information exists on the effectiveness of acute exercise to maintain arterial stiffness when performed prior to prolonged sitting, particularly within physically active individuals. METHODS: Using a randomized crossover design, 22 young, active individuals (50% female) performed two conditions 30 min of walking at 55-65% of heart rate reserve (EX) and 30 min of standing (STAND) followed by 2.5-h of sitting. Brachial-femoral (bfPWV) and femoral-ankle pulse wave velocity (faPWV) were assessed at Baseline, post-exercise and pre-sitting (Pre), and post-sitting (Post) as estimates of central and peripheral arterial stiffness, respectively. RESULTS: For bfPWV, no interaction, condition, or time effects were observed. For faPWV, an interaction was present (p < 0.001); compared to Baseline, there was a 6.1% decrease for EX (- 0.4 m/s, p < 0.001) and a 4.6% increase for STAND (0.3 m/s, p = 0.016) for STAND such that there was an 11.3% difference between conditions at Pre (0.7 m/s, p < 0.001). From Pre to Post, EX then increased by 11.7% (0.9 m/s p < 0.001) while STAND remained unchanged, resulting in no difference between conditions (0.1 m/s, p = 0.569). CONCLUSIONS: While aerobic exercise resulted in a significant decrease in faPWV prior to sitting, the prior exercise bout did not confer a protective effect against the deleterious effects of uninterrupted sitting. Future work should investigate the combined effect of prior exercise and sitting interruption strategies on markers of arterial stiffness.

The 24-h activity cycle and cardiovascular outcomes: establishing biological plausibility using arterial stiffness as an intermediate outcome.

This review proposes a biologically plausible working model for the relationship between the 24-h activity cycle (24-HAC) and cardiovascular disease. The 24-HAC encompasses moderate-to-vigorous physical activity (MVPA), light physical activity, sedentary behavior (SB), and sleep. MVPA confers the greatest relative cardioprotective effect, when considering MVPA represents just 2% of the day if physical activity guidelines (30 min/day) are met. While we have well-established guidelines for MVPA, those for the remaining activity behaviors are vague. The vague guidelines are attributable to our limited mechanistic understanding of the independent and additive effects of these behaviors on the cardiovascular system. Our proposed biological model places arterial stiffness, a measure of vascular aging, as the key intermediate outcome. Starting with prolonged exposure to SB or static standing, we propose that the reported transient increases in arterial stiffness are driven by a cascade of negative hemodynamic effects following venous pooling. The subsequent autonomic, metabolic, and hormonal changes further impair vascular function. Vascular dysfunction can be offset by using mechanistic-informed interruption strategies and by engaging in protective behaviors throughout the day. Physical activity, especially MVPA, can confer protection by chronically improving endothelial function and associated protective mechanisms. Conversely, poor sleep, especially in duration and quality, negatively affects hormonal, metabolic, autonomic, and hemodynamic variables that can confound the physiological responses to next-day activity behaviors. Our hope is that the proposed biologically plausible working model will assist in furthering our understanding of the effects of these complex, interrelated activity behaviors on the cardiovascular system.

Acute sedentary behavior and cardiovascular disease research: standardizing the methodological posture.

Sedentary behavior has been identified as an independent predictor of future cardiovascular disease risk and all-cause mortality. To explain this association, a growing body of literature has sought to investigate the physiological underpinnings of this association with the goal of developing a biologically plausible model. In time, this biologically plausible model can be tested, and effective, translatable public health guidelines can be developed. However, to ensure that evidence across studies can be effectively synthesized, it is necessary to ensure their congruency and comparability. Although there are several key factors that should be considered and controlled across prolonged sitting studies, one pertinent issue is that of participant posture. There is currently a discourse within the literature regarding the posture that cardiovascular assessments are performed in and rest periods between posture transitions and subsequent measures. This perspectives piece makes the case for standardizing approaches across the research area and offers practical recommendations for future work.

The effect of four weeks blood flow restricted resistance training on macro- and micro-vascular function in healthy, young men.

PURPOSE: To determine the macrovascular and microvascular function responses to resistance training with blood flow restriction (BFR) compared to high-load resistance training (HLRT) control group. METHODS: Twenty-four young, healthy men were randomly assigned to BFR or HLRT. Participants performed bilateral knee extensions and leg presses 4 days per week, for 4 weeks. For each exercise, BFR completed 3 X 10 repetitions/day at 30% of 1-repetition max (RM). The occlusive pressure was applied at 1.3 times of individual systolic blood pressure. The exercise prescription was identical for HLRT, except the intensity was set at 75% of one repetition maximum. Outcomes were measured pre-, at 2- and 4-weeks during the training period. The primary macrovascular function outcome was heart-ankle pulse wave velocity (haPWV), and the primary microvascular function outcome was tissue oxygen saturation (StO2) area under the curve (AUC) response to reactive hyperemia. RESULTS: Knee extension and leg press 1-RM increased by 14% for both groups. There was a significant interaction effect for haPWV, decreasing - 5% (Δ-0.32 m/s, 95% confidential interval [CI] - 0.51 to - 0.12, effect size [ES] = - 0.53) for BFR and increasing 1% (Δ0.03 m/s, 95%CI - 0.17 to 0.23, ES = 0.05) for HLRT. Similarly, there was an interaction effect for StO2 AUC, increasing 5% (Δ47%ï½¥s, 95%CI - 3.07 to 98.1, ES = 0.28) for HLRT and 17% (Δ159%ï½¥s, 95%CI 108.23-209.37, ES = 0.93) for BFR group. CONCLUSION: The current findings suggest that BFR may improve macro- and microvascular function compared to HLRT.

Sedentary Behavior Reduction: A Stepwise Approach to Increasing Physical Activity and Reducing Cardiovascular Disease Risk in Endometrial Cancer Survivors.

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.

Macrovascular and microvascular responses to prolonged sitting with and without bodyweight exercise interruptions: A randomized cross-over trial.

Exposure to uninterrupted prolonged sitting leads to macro- and microvascular complications, which can contribute to increased cardiovascular disease risk. This study investigated the macrovascular and microvascular responses to 3 h of sitting that was: (i) uninterrupted (CON); and (ii) interrupted every 20 min with 1 min light intensity half squats plus calf raises (EX). Twenty healthy participants (21 [SD: 2] years; 21.5 [SD: 1.6] kg/m2) were recruited to participate in this randomized cross-over trial. Macrovascular function was quantified using brachial-ankle pulse wave velocity (baPWV) and the lower- and upper-limb arterial stiffness index (ASI). Microvascular function was quantified as the medial gastrocnemius tissue oxygen saturation (StO2) area under the curve (AUC) during reactive hyperemia. The baPWV did not significantly change with time (p = 0.594) or by condition (p = 0.772). The arm ASI increased by 3.6 (95% CI: 0.7 to 6.6, effect size [ES] = 0.27) with a nonsignificant condition effect (p = 0.219). There was a significant interaction effect for leg ASI (p = < 0.001), with ASI increasing (impairment) by 18.7 (95% CI: 12.1 to 25.3, ES = 0.63) for CON and decreasing (improvement) by -11.9 (95% CI: -18.5 to -5.3, ES = 0.40) for EX compared to presitting. Similarly, the AUC decreased (detrimental) by 18% (Δ = -321, 95% CI: -543 to -100, ES = 0.32) for CON and increased by 32% (Δ = 588, 95% CI: 366 to 809, ES = 0.59) for EX. The leg ASI was inversely associated with StO2 AUC (interclass correlation coefficient: -0.66, 95% CI: -0.51 to -0.77). These preliminary findings suggest that regularly interrupting prolonged sitting with simple bodyweight exercises may help to preserve lower-limb vascular function.

COVID-19 infection and cardiometabolic complications: short- and long-term treatment and management considerations.

No abstract present.

Effects of compression stockings on lower-limb venous and arterial system responses to prolonged sitting: A randomized cross-over trial.

Exposure to prolonged sitting increases blood pooling and the risk of lower-extremity vascular arterial and venous complications, including deep vein thrombosis. Compression garment stockings (CGS) may prevent pooling, thereby mitigating the associated vascular complications. Three aims were addressed: (i) does use of CGS help to prevent blood pooling; (ii) does blood pooling correlate with decreased stroke volume; and (iii) does use of CGS preserve leg arterial flow-mediated dilation and reactive hyperemia response. Twenty inactive participants (22 ± 4 years, 30% female, 22.1 ± 2.0 kg/m2) were randomized to sit for 3 hours with (CGS) and without use of CGS. Blood pooling was determined using medial gastrocnemius total hemoglobin. Stroke volume was estimated using finger photoplethysmography, respectively. Macrovascular and microvascular function were measured using popliteal artery flow-mediated dilation and reactive hyperemia, respectively. In response to 3 hours of sitting: (i) there was an interaction effect for total hemoglobin (p < 0.001); the condition without use of CGS increased 10.5% (95% CI: 6.7 to 14.3) and CGS increased 4.3% (95% CI: 0.1 to 7.7); (ii) blood pooling was negatively associated with stroke volume (r = -0.58, 95% CI: -0.68 to -0.45); (iii) reactive hyperemia and flow-mediated arterial dilation was impaired after prolonged sitting, and use of CGS was not associated with attenuation of this impairment. Use of CGS decreases blood pooling but does not preserve arterial macrovascular and microvascular responses to prolonged sitting. Further study is warranted to determine whether CGS has additive benefits when combined with sitting interruption strategies.

Effect of combined home-based, overground robotic-assisted gait training and usual physiotherapy on clinical functional outcomes in people with chronic stroke: A randomized controlled trial.

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.

Health-promoting behaviours and concussion history are associated with cognitive function, mood-related symptoms and emotional-behavioural dyscontrol in former NFL players: an NFL-LONG Study.

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≤|ß|≤0.217) was associated with poorer functioning, while exercise frequency (0.064≤|ß|≤0.088) and diet quality (0.057≤|ß|≤0.086) were associated with better functioning. Sleeping under 6 hours per night (0.061≤|ß|≤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.

Cardiometabolic Health and Carotid-Femoral Pulse Wave Velocity in Children: A Systematic Review and Meta-Regression.

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.

Fitness and Fatness Are Both Associated with Cardiometabolic Risk in Preadolescents.

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.

The Effects of a Simulated Workday of Prolonged Sitting on Seated versus Supine Blood Pressure and Pulse Wave Velocity in Adults with Overweight/Obesity and Elevated Blood Pressure.

We evaluated the effects of a simulated workday of prolonged sitting on blood pressure (BP) and pulse wave velocity (PWV) and examined whether posture (seated vs. supine) affected responses. Participants (n = 25) were adults, with overweight/obesity and elevated BP, and performed seated desk work for 7.5 h. BP and PWV were measured in seated and supine postures at baseline (7:15 a.m.), midday (12:05 p.m.), and afternoon (4:45 p.m.). Generalized linear mixed models evaluated the effects of prolonged sitting on BP and PWV within each posture and interactions by posture and sex. In the recommended postures, seated BP and supine carotid-femoral pulse wave velocity (cfPWV) and carotid-ankle pulse wave velocity (caPWV), but not carotid-radial pulse wave velocity (crPWV), significantly increased over the simulated seated workday (all p < 0.05; effect sizes [d] ranged from 0.25 to 0.44). Whilst no posture-by-time interactions were observed (p > 0.05), BP, caPWV, and crPWV were higher when seated versus supine (main effects of posture p < 0.05; d ranged from 0.30 to 1.04). Exploratory analysis revealed that females had greater seated BP responses (p for interaction <0.05); seated PWV and supine BP and PWV responses were similar by sex (p for interaction >0.05). A simulated workday of prolonged sitting increased seated BP and supine cfPWV and caPWV, and posture minimally influenced these responses. These results add to the evidence suggesting a deleterious effect of prolonged sitting on cardiovascular health.

Natural killer cell mobilization and egress following acute exercise in men with prostate cancer.

NEW FINDINGS: What is the central question of this study? What are the characteristics of the NK cell response following acute moderate-intensity aerobic exercise in prostate cancer survivors and is there a relationship between stress hormones and NK cell mobilization? What is the main finding and its importance? NK cell numbers and proportions changed similarly between prostate cancer survivors and controls following acute exercise. Consecutive training sessions can likely be used without adverse effects on the immune system during prostate cancer treatment. ABSTRACT: Prostate cancer treatment affects multiple physiological systems, although the immune response during exercise has been minimally investigated. The objective was to characterize the natural killer (NK) cell response following acute exercise in prostate cancer survivors. Prostate cancer survivors on androgen deprivation therapy (ADT) and those without (PCa) along with non-cancer controls (CON) completed a moderate intensity cycling bout. NK cells were phenotyped before and 0, 2 and 24 h after acute exercise using flow cytometry. CD56 total NK cell frequency increased by 6.2% at 0 h (P < 0.001) and decreased by 2.5% at 2 h (P < 0.01) with similar findings in CD56dim cells. NK cell counts also exhibited a biphasic response. Independent of exercise, ADT had intracellular interferon γ (IFNγ) expression that was nearly twofold higher than CON (P < 0.01). PCa perforin expression was reduced by 11.4% (P < 0.05), suggesting these cells may be more prone to degranulation. CD57- NK cells demonstrated increased perforin and IFNγ frequencies after exercise with no change within the CD57+ populations. All NK and leukocyte populations returned to baseline by 24 h. NK cell mobilization and egress with acute exercise appear normal, as cell counts and frequencies in prostate cancer survivors change similarly to CON. However, lower perforin proportions (PCa) and higher IFNγ expression (ADT) may alter NK cytotoxicity and require further investigation. The return of NK cell proportions to resting levels overnight suggests that consecutive training sessions can be used without adverse effects on the immune system during prostate cancer treatment.

Sitting decreases endothelial microparticles but not circulating angiogenic cells irrespective of lower leg exercises: a randomized cross-over trial.

NEW FINDINGS: What is the central question of this study? What are the cellular and molecular determinants of increased risk for cardiovascular disease from prolonged sitting? What is the main finding and its importance? Prolonged sitting, independent of calf raise interruption strategies, decreases microparticle 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 (MPs) and circulating angiogenic cell (CACs) being promising targets. The objective of the study was 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. In a random order, 20 sedentary participants (14 females, 22 ± 3 years) remained seated for 180 min with or without performing 10 calf raises every 10 min. Blood samples were obtained after 20 min of quiet rest in the supine position before and after sitting. Overall, sitting decreased annexin V+ /CD34+ MPs (-12 ± 5 events µl-1 , P < 0.01), annexin V+ /CD62E+ MPs (-17 ± 4 events µl-1 , P < 0.001), and annexin V+ /CD31+ /42b- MPs (-22 ± 6 events µl-1 , P < 0.001) regardless of condition. There were no differences in endothelin-1 plasma concentration, CD14+ /31+ , CD34+ or CD3+ /31+ CAC frequencies. 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 behaviour and provide new insights into altered intercellular communication with physical inactivity such as prolonged sitting.

Endothelium function dependence of acute changes in pulse wave velocity and flow-mediated slowing.

Flow-mediated slowing (FMS), defined as the minimum pulse wave velocity (PWVmin) during reactive hyperemia, is potentially a simple, user-objective test for examining endothelial function. The purpose of the current study was to determine the effects of a known endothelial dysfunction protocol on arm PWV and PWVmin. Complete data were successfully collected in 22 out of 23 healthy adults (23.8 years [SD 4.1], 16 F, 22.8 kg/m2 [SD 2.8]). Local endothelial dysfunction was induced by increasing retrograde shear stress in the upper arm, through inflation of a distal (forearm) tourniquet to 75 mmHg, for 30 min. Pre- and post-endothelial dysfunction, PWV was measured followed by simultaneous assessment of PWVmin and flow-mediated dilation (FMD). PWV was measured between the upper arm and wrist using an oscillometric device, and brachial FMD using ultrasound. FMD (%) and PWVmin (m/s) were calculated as the maximum increase in diameter and minimum PWV during reactive hyperemia, respectively. Endothelial dysfunction resulted in a large effect size (ES) decrease in FMD (∆ = -3.10%; 95% CI: -4.15, -2.05; ES = -1.3), and a moderate increase in PWV (∆ = 0.38 m/s; 95% CI: 0.07, 0.69; ES = 0.5) and PWVmin (∆ = 0.16 m/s; 95% CI: 0.05, 0.28; ES = 0.6). There was a large intra-individual (pre- vs post-endothelial dysfunction) association between FMD and PWVmin (r = -0.61; 95% CI: -0.82, -0.24). In conclusion, acute change in PWV and PWVmin are at least partially driven by changes in endothelial function.

Circuit resistance training and cardiovascular health in breast cancer survivors.

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.

Associations of accelerometer-measured sedentary time, sedentary bouts, and physical activity with adiposity and fitness in children.

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.

Universal Healthcare in the United States of America: A Healthy Debate.

This commentary offers discussion on the pros and cons of universal healthcare in the United States. Disadvantages of universal healthcare include significant upfront costs and logistical challenges. On the other hand, universal healthcare may lead to a healthier populace, and thus, in the long-term, help to mitigate the economic costs of an unhealthy nation. In particular, substantial health disparities exist in the United States, with low socio-economic status segments of the population subject to decreased access to quality healthcare and increased risk of non-communicable chronic conditions such as obesity and type II diabetes, among other determinants of poor health. While the implementation of universal healthcare would be complicated and challenging, we argue that shifting from a market-based system to a universal healthcare system is necessary. Universal healthcare will better facilitate and encourage sustainable, preventive health practices and be more advantageous for the long-term public health and economy of the United States.