The impact of uninterrupted sitting on central and peripheral cardiovascular function in pre-menopausal and post-menopausal women.

Independently, both prolonged uninterrupted sitting and the onset of menopause negatively impact markers of cardiovascular risk. Whether their combination augment these responses additively remains unknown. This study assessed whether prolonged uninterrupted sitting causes greater central and peripheral cardiovascular dysfunction in post-menopausal women compared to pre-menopausal women. To address this, 23 healthy women (13 pre-menopausal [43.77 ± 4.30 years] and 10 post-menopausal [57.20 ± 8.55 years]) sat uninterrupted for 2-h. Carotid-femoral pulse wave velocity (cf-PWV), pulse wave analysis (PWA), lower limb venous pooling (HHb), and calf circumference were assessed pre-and post-sitting using general linear mixed models, with age as a covariate. Changes in MAP over time (both between and within groups) was assessed using a two-way repeated-measures-ANOVA. There were no significant interactions for any outcome measures. However, for cf-PWV, there was a significant main effect of group (Δ = 0.854 ± 0.354 m s-1; p = 0.026, ηp2 = 0.707). For PWA, only heart rate (HR) and pressure forwards (Pf) showed significant main effects 13 of time [Δ = 6 ± 1 bts-min-1, p < 0.001, ηp2 = 0.861] and group [Δ = 3.893 ± 1.450 mmHg, p = 0.016, ηp2 = 0.271], respectively. Both HHb (Δ = 2.737 ± 0.952, p = 0.009, ηp2 = 0.742) and calf circumference (Δ = 0.812 ± 0.128 cm, p < 0.001, ηp2 = 0.863) significantly increased over time. Whilst post-menopausal women demonstrated greater overall arterial stiffness (increased cf-PWV at baseline), there was no difference in cardiovascular response (central or peripheral) to 2-h of prolonged sitting between the pre- and post-menopausal women.

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.

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.

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.

Validity and reliability of lower-limb pulse-wave velocity assessments using an oscillometric technique.

NEW FINDINGS: What is the central question of this study? There is growing interest in the effects of sedentarism on central and peripheral cardiovascular health. To permit further investigation, including larger epidemiological studies, there is a need to identify arterial health assessment tools that are valid (accurate) and reliable (precise), yet practical. What is the main finding and its importance? Lower-limb vascular health (femoral-ankle pulse-wave velocity) can be determined in a supine position with accuracy and precision using an oscillometrically based device. This technology might help to improve our understanding of the pathological mechanisms linking cardiovascular disease to sedentarism, including the interaction between peripheral and central vasculature. ABSTRACT: There is a growing interest in the deleterious effects of sedentary behaviour on lower-limb arterial health. To permit further investigation, including larger epidemiological studies, there is a need to identify lower-limb arterial health assessment tools that are valid and reliable, yet simple to administer. In this study, we sought to determine the validity and between-day reliability of femoral-ankle pulse-wave velocity (faPWV) measures obtained using an oscillometrically based device (SphygmocCor XCEL) in supine and seated positions. Doppler ultrasound was used as the criterion. A total of 47 healthy adults were recruited for validity (n = 32) and reliability (n = 15) analyses. Validity was determined by measuring faPWV in seated and supine positions using the XCEL and Doppler ultrasound devices, in a randomized order. Between-day reliability was determined by measuring seated and supine faPWV using the XCEL on three different mornings, separated by a maximum of 7 days. The validity criterion [absolute standard error of estimate (aSEE) < 1.0 m s-1 ] was met in the supine [aSEE = 0.8 m s-1 , 95% confidence interval (CI) 0.4-1.0], but not in the seated (aSEE = 1.2 m s-1 , 95% CI 1.1-1.2) position. Intraclass correlation coefficient (ICC) estimates revealed that the XCEL demonstrated good reliability in the supine position (ICC = 0.83, 95% CI 0.65-0.93), but poor reliability in the seated position (ICC = 0.29, 95% CI 0.23-0.63). The oscillometric XCEL device can be used to determine lower-limb pulse-wave velocity with acceptable validity and reliability in the conventionally recommended supine position, but not in the seated position.

Carotid artery wall mechanics in young males with high cardiorespiratory fitness.

NEW FINDINGS: What is the central question of this study? Common carotid artery (CCA) two-dimensional strain imaging detects intrinsic arterial wall properties beyond conventional measures of arterial stiffness, but the effect of cardiorespiratory fitness on two-dimensional strain-derived indices of CCA stiffness is unknown. What is the main finding and its importance? Two-dimensional strain imaging of the CCA revealed greater peak circumferential strain and systolic strain rate in highly fit men compared with their less fit counterparts. Altered CCA wall mechanics might reflect intrinsic training-induced adaptations that help to buffer the increase in pulse pressure and stroke volume during exercise. ABSTRACT: The influence of cardiorespiratory fitness on arterial stiffness in young adults remains equivocal. Beyond conventional measures of arterial stiffness, two-dimensional strain imaging of the common carotid artery (CCA) provides new information related to the intrinsic properties of the arterial wall. Therefore, the aim of this study was to assess the effect of cardiorespiratory fitness on both conventional indices of CCA stiffness and two-dimensional strain parameters, at rest and after a bout of aerobic exercise in young, healthy men. Short-axis ultrasound images of the CCA were recorded in 34 healthy men {22 years old [95% confidence interval (CI), 19, 22]} before and immediately after 5 min of aerobic exercise (40% of maximal oxygen consumption). Images were analysed for arterial diameter, peak circumferential strain (PCS) and peak systolic and diastolic strain rates (S-SR and D-SR). Heart rate, systolic and diastolic blood pressure were simultaneously assessed, and Peterson's elastic modulus (Ep ) and ß-stiffness (ß1 ) were calculated. Participants were separated post hoc into moderate- and high-fitness groups [maximal oxygen consumption, 48.9 (95% CI, 44.7, 53.2) versus 65.6 ml kg-1  min-1 (95% CI, 63.1, 68.1), respectively; P < 0.001]. The Ep and ß1 were similar between groups at baseline (P > 0.13) but were elevated in the moderate-fitness group postexercise (P < 0.04). The PCS and S-SR were elevated in the high-fitness group at both time points [3.0% (95% CI, 1.2, 4.9), P = 0.002, and 0.401 s-1 (95% CI, 0.085, 0.72), P = 0.02, respectively]. No group differences were observed in CCA heart rate, systolic or diastolic blood pressure or D-SR throughout the protocol (P > 0.05). Highly fit individuals exhibit elevated CCA, PCS and S-SR, which might reflect training-induced adaptations that help to buffer the increase in pulse pressure and stroke volume during exercise.

A Community-Based, Bionic Leg Rehabilitation Program for Patients with Chronic Stroke: Clinical Trial Protocol.

Stroke is a major global health problem whereby many survivors have unmet needs concerning mobility during recovery. As such, the use of robotic-assisted devices (i.e., a bionic leg) within a community setting may be an important adjunct to normal physiotherapy in chronic stroke survivors. This study will be a dual-center, randomized, parallel group clinical trial to investigate the impact of a community-based training program using a bionic leg on biomechanical, cardiovascular, and functional outcomes in stroke survivors. Following a baseline assessment that will assess gait, postural sway, vascular health (blood pressure, arterial stiffness), and functional outcomes (6-minute walk), participants will be randomized to a 10-week program group, incorporating (1) a physiotherapy plus community-based bionic leg training program; (2) physiotherapy only; or (3) usual care control. The training program will involve participants engaging in a minimum of 1 hour per day of bionic leg activities at home. Follow-up assessments, identical to baseline, will occur after 10 weeks, and 3 and 12 months postintervention. Given the practical implications of the study, the clinical significance of using the bionic leg will be assessed for each outcome variable. The potential improvements in gait, balance, vascular health, and functional status may have a meaningful impact on patients' quality of life. The integration of robotic devices within home-based rehabilitation programs may prove to be a cost-effective, practical, and beneficial resource for stroke survivors.

The effect of cardiorespiratory fitness and habitual physical activity on cardiovascular responses to 2 h of uninterrupted sitting.

Prolonged uninterrupted sitting of >3 h has been shown to acutely cause central and peripheral cardiovascular dysfunction. However, individuals rarely sit uninterrupted for >2 h, and the cardiovascular response to this time is currently unknown. In addition, while increased cardiorespiratory fitness (CRF) and habitual physical activity (HPA) are independently associated with improvements in central and peripheral cardiovascular function, it remains unclear whether they influence the response to uninterrupted sitting. This study sought to 1) determine whether 2 h of uninterrupted sitting acutely impairs carotid-femoral pulse wave velocity (cfPWV), femoral ankle PWV (faPWV), and central and peripheral blood pressure and 2) investigate the associations between CRF and HPA versus PWV changes during uninterrupted sitting. Following 2 h of uninterrupted sitting, faPWV significantly increased [mean difference (MD) = 0.26 m·s-1, standard error (SE) = 0.10, P = 0.013] as did diastolic blood pressure (MD = 2.83 mmHg, SE = 1.08, P = 0.014), however, cfPWV did not significantly change. Although our study shows 2 h of uninterrupted sitting significantly impairs faPWV, neither CRF (r = 0.105, P = 0.595) nor HPA (r = -0.228, P = 0.253) was associated with the increases.NEW & NOTEWORTHY We demonstrate that neither cardiorespiratory fitness nor habitual physical activity influence central and peripheral cardiovascular responses to a 2-h bout of uninterrupted sitting in healthy young adults.

Effects of playing surface on physiological responses and performance variables in a controlled football simulation.

In spite of the increased acceptance of artificial turf in football, few studies have investigated if matches are altered by the type of surface used and no research has compared physiological responses to football activity on artificial and natural surfaces. In the present study, participants performed a football match simulation on high-quality artificial and natural surfaces. Neither mean heart rate (171 ± 9 beats · min(-1) vs. 171 ± 9 beats · min(-1); P > 0.05) nor blood lactate (4.8 ± 1.6 mM vs. 5.3 ± 1.8 mM; P > 0.05) differed between the artificial and natural surface, respectively. Measures of sprint, jumping and agility performance declined through the match simulation but surface type did not affect the decrease in performance. For example, the fatigue index of repeated sprints did not differ (P > 0.05) between the artificial, (6.9 ± 2.1%) and natural surface (7.4 ± 2.4%). The ability to turn after sprinting was affected by surface type but this difference was dependent on the type of turn. Although there were small differences in the ability to perform certain movements between artificial and natural surfaces, the results suggest that fatigue and physiological responses to football activity do not differ markedly between surface-type using the high-quality pitches of the present study.

Effects of intermittent exercise during prolonged sitting on executive function, cerebrovascular, and psychological response: a randomized crossover trial.

Emerging evidence indicates that acute bouts of uninterrupted prolonged sitting decrease cerebral blood flow and impair executive function. Few studies have investigated the use of feasible sedentary behavior interruptions to attenuate these effects. This study aimed to investigate the effects of intermittent half-squat exercises during prolonged sitting on executive function. Twenty participants (45% women, 21 ± 1 yr) were randomized to sit for 3 h 1) without any interruptions (control) or 2) with 1 min half-squats every 20 min (exercise). Executive function was determined using the Color Word Stroop Test (CWST) and Trail Making Test-B (TMT-B). Subjective feelings of arousal and measures of fatigue, concentration, and motivation were evaluated. Internal carotid artery (ICA) blood flow was measured using Doppler ultrasound. There was a significant interaction effect for correct response times with the incongruent CWST (P < 0.01), which were 3.5% faster in the exercise and 4.2% slower in the control over 3 h of sitting. There was also a significant interaction effect for TMT-B completion times (P < 0.01), which were 10.0% faster in the exercise and 8.8% slower in the control. Exercise suppressed decreases in concentration with a significant interaction effect (-28.7% vs. -9.2% for control vs. exercise, P = 0.048) and increases in mental fatigue with a significant interaction effect (285% vs. 157% for control vs. exercise, P < 0.04). These changes may have been related to changes in ICA blood flow, which had a significant interaction effect (P = 0.087). These results suggest that a simple strategy like intermittent squat exercises could help to maintain executive function during prolonged sitting.NEW & NOTEWORTHY We assessed executive function, cardiovascular, and cerebrovascular responses during 3-h prolonged sitting, with or without an exercise interruption (1 min squats every 20 min). Compared to uninterrupted sitting, exercise interruption suppressed sitting-induced reductions in cerebral blood flow and impairments in executive function. These results demonstrated the efficacy of a half-squat intervention for individuals seeking to preserve cognition during prolonged sitting, which may be useful in environments with limited resources such as the workplace.

Effect of home-based, overground robotic-assisted gait training on vascular health in people with chronic stroke.

Overground robotic-assisted gait training (O-RAGT) has been shown to improve clinical functional outcomes in people living with stroke. The purpose of this study was to identify whether a home-based O-RAGT program, in combination with usual care physiotherapy, would demonstrate improvements in vascular health in individuals with chronic stroke, and, whether any changes in vascular outcomes would be sustained 3 months after completing the program. Thirty-four participants with chronic stroke (between 3 months and 5 years post-stroke) were randomized to either a 10-week O-RAGT program in combination with usual care physiotherapy, or to a usual care physiotherapy only control group. Participants' (n = 31) pulse wave analysis (PWA), and regional [carotid-femoral pulse wave analysis (cfPWV)] and local (carotid) measures of arterial stiffness were assessed at baseline, post-intervention, and 3-month post-intervention. Analysis of covariance demonstrated a significant reduction (improvement) in cfPWV between BL and PI for O-RAGT (8.81 ± 2.51 vs. 7.92 ± 2.17 m/s, respectively), whilst the control group remained unchanged (9.87 ± 2.46 vs. 9.84 ± 1.76 m/s, respectively; p < 0.05; ηp2 = 0.14). The improvement in cfPWV was maintained 3 months after completing the O-RAGT program. There were no significant Condition by Time interactions for all PWA and carotid arterial stiffness measures (p > 0.05). A significant increase in physical activity, as determined by the time spent stepping, was observed for O-RAGT between baseline and post-intervention assessments (3.2 ± 3.0-5.2 ± 3.3%, respectively) but not for CON (p < 0.05). The improvement in cfPWV, in combination with an increase in physical activity whilst wearing the O-RAGT and concomitant reduction in sedentary behavior, are important positive findings when considering the application of this technology for "at home" rehabilitation therapy for stroke survivors. Further research is needed to determine whether implementing "at home" O-RAGT programs should be a part of the stroke treatment pathway. Clinical trial registration: https://clinicaltrials.gov, identifier NCT03104127.

Localized activity attenuates the combined impact of a high fat meal and prolonged sitting on arterial stiffness: A randomized, controlled cross-over trial.

Exposure to acute prolonged sitting and consumption of a high fat (HF) meal have been shown to independently and additively impair central and peripheral cardiovascular function. This study sought to determine whether localized activity, namely leg fidgeting, offers a protective effect to these deleterious effects. Using a randomized crossover design with three trials, 18 healthy males sat uninterrupted for 180 min following the consumption of a low fat (LF, trial 1) or HF meal (trial 2). The third trial consisted of a HF meal but sitting was interrupted with 1 min of leg fidgeting (isolated bilateral plantar flexion) consisting of -250 taps per min every 5 min for the 180 min duration. Carotid-femoral pulse wave velocity (cfPWV), aortic-femoral stiffness gradient (af-SG), superficial femoral blood flow, shear-rate and PWVß, triglyceride concentrations and lower-limb venous pooling (HHb) were assessed pre and post sitting in all trials. General linear mixed model found that following the uninterrupted HF trial, there was a significant worsening of cfPWV (mean difference (MD) = 0.57 mˑs-1; d = 1.04) and the af-SG (MD = 0.14, d = 0.50), and femoral artery blood flow (MD = 18 mlˑmin-1; d = 0.48) and shear rate (MD = 15 S1; d = 0.67) decreased. However, leg fidgeting was enough to prevent the combined deleterious effects of prolonged sitting following a HF meal. As there were no significant changes in the LF trial, the HF meal maybe the predominant driver when uninterrupted sitting is combined with a HF meal.

Pulse-wave velocity assessments derived from a simple photoplethysmography device: Agreement with a referent device.

Objective: Pulse-wave velocity (PWV), a common measure of arterial stiffness, can be measured continuously and across multiple body sites using photoplethysmography (PPG). The objective was to determine whether a simple photoplethysmography PPG PWV method agrees with a referent device. Approach: Photoplethysmography heart-finger PWV (hfPWV) and heart-toe PWV (htPWV) were compared to oscillometric carotid-wrist PWV (cwPWV) and carotid-ankle PWV (caPWV) referent measurements, respectively. In 30 adults (24.6 ± 4.8 years, body mass index 25.2 ± 5.9 kg/m2, 18 female), three measurements were made: two supine baseline measurements (Base 1, Base 2) and one measurement (Tilt) 5 min after a modified head-up tilt test (mHUTT). Overall agreement and repeated measures agreement (change in PPG PWV from Base to Tilt vs. change in referent PWV from Base to Tilt) were calculated using linear mixed models. Agreement estimates were expressed as intra-class correlation coefficients (ICC). Main results: For hfPWV there was strong overall agreement (ICC: 0.77, 95%CI: 0.67-0.85), but negligible and non-significant repeated measures agreement (ICC: 0.10, 95%CI: -0.18 to 0.36). For htPWV, there was moderate overall agreement (ICC:0.50, 95%CI: 0.31-0.65) and strong repeated measures agreement (ICC: 0.81, 95%CI: 0.69-0.89). Significance: Photoplethysmography can continuously measure PWV at multiple arterial segments with moderate-strong overall agreement. While further work with upper-limb PPG PWV is needed, PPG can adequately capture acute changes in lower-limb PWV.

Reimagining the Value of Brachial-Ankle Pulse Wave Velocity as a Biomarker of Cardiovascular Disease Risk-A Call to Action on Behalf of VascAgeNet.

This review critiques the literature supporting clinical assessment and management of cardiovascular disease and cardiovascular disease risk stratification with brachial-ankle pulse wave velocity (baPWV). First, we outline what baPWV actually measures-arterial stiffness of both large central elastic arteries and medium-sized muscular peripheral arteries of the lower limb. Second, we argue that baPWV is not a surrogate for carotid-femoral pulse wave velocity. While both measures are dependent on the properties of the aorta, baPWV is also strongly dependent on the muscular arteries of the lower extremities. Increased lower-extremity arterial stiffness amplifies and hastens wave reflections at the level of the aorta, widens pulse pressure, increases afterload, and reduces coronary perfusion. Third, we used an established evaluation framework to identify the value of baPWV as an independent vascular biomarker. There is sufficient evidence to support (1) proof of concept; (2) prospective validation; (3) incremental value; and (4) clinical utility. However, there is limited or no evidence to support (5) clinical outcomes; (6) cost-effectiveness; (8) methodological consensus; or (9) reference values. Fourth, we address future research requirements. The majority of the evaluation criteria, (1) proof of concept, (2) prospective validation, (3) incremental value, (4) clinical utility and (9) reference values, can be supported using existing cohort datasets, whereas the (5) clinical outcomes and (6) cost-effectiveness criteria require prospective investigation. The (8) methodological consensus criteria will require an expert consensus statement. Finally, we finish this review by providing an example of a future clinical practice model.

Left ventricular mechanics in humans with high aerobic fitness: adaptation independent of structural remodelling, arterial haemodynamics and heart rate.

Individuals with high aerobic fitness have lower systolic left ventricular strain, rotation and twist ('left ventricular (LV) mechanics') at rest, suggesting a beneficial reduction in LV myofibre stress and more efficient systolic function. However, the mechanisms responsible for this functional adaptation are not known and the influence of aerobic fitness on LV mechanics during dynamic exercise has never been studied. We assessed LV mechanics, LV wall thickness and dimensions, central augmentation index (AIx), aortic pulse wave velocity (aPWV), blood pressure and heart rate in 28 males (age: 21±2 years SD) with a consistent physical activity level (no change>6 months). Individuals were examined at rest and during exercise (40% peak exercise capacity) and separated post hoc into a moderate and high aerobic fitness group (˙V(O2peak): 49 ± 5 and 63 ± 7ml kg−1 min−1, respectively, P <0.0001). At rest and during exercise, there were no significant differences in gross LVstructure, AIx, blood pressure or heart rate (P >0.05).However, for the same AIx, the high ˙V(O2peak) group had significantly lower LV apical rotation (P =0.002) and LV twist (P =0.003) while basal rotation and strain indices did not differ between groups (P >0.05).We conclude that young males with high aerobic fitness have lower LVapical rotation at rest and during submaximal exercise that can occur without changes in gross LV structure, arterial haemodynamics or heart rate. The findings suggest a previously unknown type of physiological adaptation of the left ventricle that may have important implications for exercise training in older individuals and patient populations in which exercise training has previously failed to show clear benefits for LV function.

The Effects of Acute Exposure to Prolonged Sitting, with and Without Interruption, on Peripheral Blood Pressure Among Adults: A Systematic Review and Meta-Analysis.

BACKGROUND: Previous reviews have shown that exposure to acute prolonged sitting can have detrimental effects on several cardiovascular and cardiometabolic health markers. However, to date, there has been no synthesis of peripheral blood pressure data (including systolic blood pressure, diastolic blood pressure and mean arterial pressure), an important and translatable marker of cardiovascular health. Similarly, no previous study has consolidated the effects of sitting interruptions on peripheral blood pressure. OBJECTIVES: We aimed to (1) assess the effect of exposure to acute prolonged sitting on peripheral blood pressure and (2) determine the efficacy of sitting interruption strategies as a means of offsetting any negative effects. Subgroup analyses by age and interruption modality were performed to explore heterogeneity. DATA SOURCES: Electronic databases (PubMed, Web of Science and, SPORTDiscus) were searched from inception to March 2021. Reference lists of eligible studies and relevant reviews were also screened. STUDY SELECTION: Inclusion criteria for objective (1) were: (i) peripheral blood pressure was assessed non-invasively in the upper limb pre-sitting and post-sitting; (ii) studies were either randomised controlled, randomised crossover or quasi-experimental pre-test vs post-test trials; (iii) the sitting period was ≥ 1 h; (iv) pre-sitting and post-sitting measures were performed in the same posture; and (v) participants were adults (aged ≥ 18 years), free of autonomic or neuromuscular dysfunction. Additional criteria for objective (2) were: (i) the interruption strategy was during the sitting period; (ii) there was an uninterrupted sitting control condition; and (iii) the interruption strategy must have involved participants actively moving their upper or lower limbs. APPRAISAL AND SYNTHESIS METHODS: In total, 9763 articles were identified, of which 33 met inclusion criteria for objective (1). Of those articles, 22 met inclusion criteria for objective (2). Weighted mean difference (WMD), 95% confidence intervals (95% CI), and standardised mean difference (SMD) were calculated for all trials using inverse variance heterogeneity meta-analysis modelling. Standardised mean difference was used to determine the magnitude of effect, where < 0.2, 0.2, 0.5 and 0.8 were defined as trivial, small, moderate and large, respectively. RESULTS: (1) Prolonged uninterrupted sitting resulted in trivial and small significant increases in systolic blood pressure (WMD = 3.2 mmHg, 95% CI 0.6 to 5.8, SMD = 0.14) and mean arterial pressure (WMD = 3.3 mmHg, 95% CI 2.2 to 4.4, SMD = 0.37), respectively, and a non-significant trivial increase in diastolic blood pressure. Subgroup analyses indicated that the increases in systolic blood pressure and mean arterial pressure were more pronounced in younger age groups. (2) Interrupting bouts of prolonged sitting resulted in significantly lower systolic blood pressure (WMD = - 4.4 mmHg, 95% CI - 7.4 to - 1.5, SMD = 0.26) and diastolic blood pressure (WMD = - 2.4 mmHg, 95% CI - 4.5 to - 0.3, SMD = 0.19) compared with control conditions, particularly when using aerobic interruption strategies. CONCLUSIONS: Exposure to acute prolonged uninterrupted sitting results in significant increases in systolic blood pressure and mean arterial pressure, particularly in younger age groups. Regularly interrupting bouts of prolonged sitting, particularly with aerobic interruption strategies may reduce negative effects.

Leg Fidgeting Improves Executive Function following Prolonged Sitting with a Typical Western Meal: A Randomized, Controlled Cross-Over Trial.

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.

Associations of lower-limb atherosclerosis and arteriosclerosis with cardiovascular risk factors and disease in older adults: The Atherosclerosis Risk in Communities (ARIC) study.

BACKGROUND & AIMS: Atherosclerosis and arteriosclerosis contribute to vascular aging and cardiovascular disease (CVD) risk. Both processes can be assessed simply in the lower-limbs and reflect systemic pathology. However, only atherosclerosis is routinely assessed, typically via ankle-brachial index (ABI). Arteriosclerosis can be assessed using femoral-ankle pulse wave velocity (faPWV), but no studies have identified whether ABI and faPWV similarly associate with overt CVD and risk factors, nor whether faPWV confers additional information. The aims of this study were to (i) compare associations of ABI and faPWV with traditional CVD risk factors, including age, sex, systolic blood pressure (SBP), high-density lipoprotein (HDL), total cholesterol (TC), smoking, and diabetes; and (ii) determine the independent and additive associations of ABI and faPWV with a composite measure of prevalent CVD. METHODS: We evaluated ABI and faPWV in 4330 older-aged (75.3 ± 5.0 years) adults using an oscillometric screening device. Associations between ABI and faPWV with CVD risk factors and CVD were determined using mixed-model linear- and logistic-regression. RESULTS: ABI and faPWV were associated with age, HDL, and smoking. ABI was associated with sex, TC, diabetes. faPWV was associated with SBP. Both ABI and faPWV were inversely associated with CVD. Low ABI (≤0.9 vs. >0.9) and low faPWV (≤9.94 vs. >9.94) increased the odds of CVD by 2.41-fold (95% CI:1.85,3.17) and 1.46-fold (95% CI:1.23,1.74), respectively. The inverse association between faPWV and CVD was independent of ABI and CVD risk factors. CONCLUSIONS: ABI and faPWV, measures of lower-limb atherosclerosis and arteriosclerosis, are independently associated with CVD risk factors and prevalent CVD. Assessment of faPWV may confer additional risk information beyond ABI.

Physical Activity, Mental Health and Wellbeing of Adults within and during the Easing of COVID-19 Restrictions, in the United Kingdom and New Zealand.

Physical activity (PA) participation was substantially reduced at the start of the COVID-19 pandemic. The purpose of this study was to assess the association between PA, mental health, and wellbeing during and following the easing of COVID-19 restrictions in the United Kingdom (UK) and New Zealand (NZ). In this study, 3363 adults completed online surveys within 2-6 weeks of initial COVID-19 restrictions (April/May 2020) and once restrictions to human movement had been eased. Outcome measures included the International Physical Activity Questionnaire Short-Form, Depression Anxiety and Stress Scale-9 (mental health) and World Health Organisation-5 Wellbeing Index. There were no differences in PA, mental health or wellbeing between timepoints (p > 0.05). Individuals engaging in moderate or high volume of PA had significantly better mental health (-1.1 and -1.7 units, respectively) and wellbeing (11.4 and 18.6 units, respectively) than individuals who engaged in low PA (p < 0.001). Mental health was better once COVID-19 restrictions were eased (p < 0.001). NZ had better mental health and wellbeing than the UK (p < 0.001). Participation in moderate-to-high volumes of PA was associated with better mental health and wellbeing, both during and following periods of COVID-19 containment, compared to participation in low volumes of PA. Where applicable, during the current or future pandemic(s), moderate-to-high volumes of PA should be encouraged.