The endothelium is the innermost layer of the blood vessels and is responsible for the production of chemicals that are used to regulate arterial diameter in response to changes in blood flow. Dysfunction of the endothelium is a key precursor for cardiovascular disease. However, exercise training may mitigate this dysfunction and promote endothelial health. Therefore, this infographic illustrates findings from an umbrella review (review of reviews; 10.1007/s40279-023-01837-w) that investigated the impact of any exercise training intervention (intervention) on adults with or without chronic disease (population), with, or without a comparator group (comparison), on endothelial function (outcome) using evidence from 27 reviews, including 19 meta-analyses (5464 unique participants). Overall, the included reviews provided evidence that the type of training to optimally improve endothelial function may vary based on disease condition. Specifically, the evidence suggests that healthy adults benefitted most from high intensity aerobic training and/or more frequent low-moderate resistance training. In addition, adults with type 2 diabetes benefitted most from low-intensity resistance or low-moderate aerobic exercise training, whereas those with cardiovascular conditions (i.e., heart transplant patients, peripheral artery disease, heart failure, hypertension, and cerebrovascular disease) should consider engaging in higher-intensity aerobic training to improve endothelial function, although may still need to consult a healthcare provider. Exercise training also improves endothelial function in other chronic conditions including cancer and autoimmune rheumatic disease, but the evidence is insufficient to provide specific guidelines. Although insufficient data exists to determine specific intervention characteristics (i.e., frequency, intensity, type, time), this information provides a high level of evidence to support exercise training, including aerobic, resistance, and combined training as effective strategies to improve endothelial-dependent vasodilatory function in adults. These findings should help guide the design of specific exercise programs or recommendations.
Engaging in muscle strengthening activities (e.g., resistance training) at least twice/week is promoted by (Inter)national movement guidelines. Cardiovagal baroreflex sensitivity (cvBRS) reflects the ability to modulate R-R interval in response to changes in systolic blood pressure. Given the current conflicting literature, this study posed to explore the relationship between self-report muscle strengthening frequency and spontaneous cvBRS. 114 adults (62 females; age: 33 ± 19 years, 22% >55 years; body mass index: 24.2 ± 3.7 kg/m
The pressor responses to spontaneous bursts of muscle sympathetic nerve activity provide important information regarding sympathetic regulation of the circulation. Many laboratories worldwide quantify sympathetic neurohemodynamic transduction using in-house, customized software requiring high-level programming skills and/or costly computer programs. To overcome these barriers, this study presents a simple, open-source, Microsoft Excel-based analysis program along with video instructions to assist researchers without the necessary resources to quantify sympathetic neurohemodynamic transduction.
Introduction: Single bouts of prolonged bent-legged sitting attenuate popliteal endothelial-dependent vasodilation (as assessed via flow-mediated dilation [FMD]), which is partially attributed to arterial ‘kinking’. However, the impact of knee-flexion angle on sitting-induced popliteal FMD is unknown. The objective of this study was to perform separate laboratory and free-living studies to test the hypotheses that: (1) popliteal FMD impairments would be graded between knee flexions at 90° (bent-legged sitting) > 45° > 0° (straight-legged sitting) following a 3-hour bout of sitting; and (2) more habitual time spent bent-legged sitting (< 45°) would be associated with lower FMD. Methods: The laboratory study included eight young, healthy adults (24 ± 2 years; four women) who underwent two sitting bouts over 2 days with one leg positioned at a knee-flexion angle of 0° or 90° and the opposite leg at 45° knee flexion. Popliteal FMD was assessed at pre- and postsitting timepoints. Results: Sitting-induced reductions in FMD were similar between all knee-flexion angles (all, p > 0.674). The free-living study included 35 young, healthy adults (23 ± 3 years; 16 women) who wore three activPAL monitors (torso, thigh, shin) to determine detailed sedentary postures. Time spent sedentary (624 ± 127 min/day), straight-legged sitting (112 ± 98 min/day), and bent-legged sitting (442 ± 106 min/day) were not related to relative FMD (5.3 ± 1.8%; all, p > 0.240). Conclusion: These findings suggest that knee-flexion angle-mediated arterial ‘kinking’ during sitting is not a major contributor toward sitting-induced popliteal endothelial-dependent vasodilatory dysfunction.
The efficacy of exercise referral schemes (ERS) involving primary care providers to an exercise specialist on patients' physical activity is uncertain and primarily based on self-report outcomes. Cardiorespiratory endurance carries clinically relevant information and is an objective outcome measure that has been used to evaluate ERS, but this literature has not been amalgamated. We determined the effectiveness of ERS involving qualified exercise professionals (QEPs) on patients' cardiorespiratory endurance.
The activPAL is a widely-used measure of sedentary time but few studies have evaluated its ability to estimate physical activity intensity. This study determined the accuracy of the algorithm used by the activPAL to predict metabolic equivalents (METs) from cadence and a curvilinear cadence-METs equation individualized for height. Thirty-six healthy adults (25 ± 6 years) completed a progressive walking protocol. Stepping cadence was video recorded and METs were determined via indirect calorimetry. Manually-counted cadence was input into the activPAL and curvilinear equations. The internal activPAL equation overpredicted METs at slower cadences (<120 steps/minute) but underpredicted METs at faster cadences (>120 step/minute) (proportional bias, p < .001). Conversely, the curvilinear equation exhibited neither fixed (p = .37) nor proportional bias (p = .07), and a lower absolute MET difference [0.87 ± 0.65 (range:0.0–3.2) vs. 0.56 ± 0.45 (range:0.0–2.7) METs]. The linear activPAL equation poorly estimates METs from stepping cadence but these inaccuracies may be lessened through the use of an individualized curvilinear equation.
We previously observed that brachial artery (BA) low-flow-mediated constriction (L-FMC) is inversely related to aerobic fitness (i.e., V̇o2peak) in older adults (OA). However, it is unclear if an L-FMC response is elicited in the popliteal artery (POP) or if a similar inverse relationship with aerobic fitness exists. Considering that the POP experiences larger shear stress fluctuations during sedentary behaviors and traditional lower limb modes of aerobic exercise, we tested the hypotheses that 1) heterogeneous L-FMC responses exist between the BA versus POP of OA, and 2) that aerobic fitness will be inversely related to POP L-FMC. L-FMC was assessed in 47 healthy OA (30 women, 67 ± 5 yr) using duplex ultrasonography and quantified as the percent decrease in diameter (from baseline) during the last 30 s of a 5-min distal cuff occlusion period. When allometrically scaled to baseline diameter, the BA exhibited a greater L-FMC response than the POP (-1.3 ± 1.6 vs. -0.4 ± 1.6%; P = 0.03). Furthermore, L-FMC responses in the BA and POP were not correlated (r = 0.22; P = 0.14). V̇o2peak was strongly correlated to POP L-FMC (r = -0.73; P < 0.001). The heterogeneous BA versus POP L-FMC data indicate that upper limb L-FMC responses do not represent a systemic measure of endothelial-dependent vasoconstrictor capacity in OA. The strong association between V̇o2peak and POP L-FMC suggests that localized shear stress patterns, perhaps induced by lower limb dominant modes of aerobic exercise, may result in greater vasoconstrictor responsiveness in healthy OA. NEW & NOTEWORTHY We compared low-flow-mediated constriction responses between the brachial and popliteal arteries of healthy older adults. Vasoconstrictor responses were not correlated between arteries. A strong relationship between aerobic fitness and low-flow-mediated vasoconstriction was observed in the popliteal artery. These findings suggest that brachial vasoconstrictor responsiveness is not reflective of the popliteal artery, which is exposed to larger shear stress fluctuations during bouts of sedentary behavior and traditional lower limb modes of exercise.
The purpose of the study was to: 1) Validate the PiezoRx® for steps and intensity related physical activity in free-living conditions compared to the criterion measure. 2) Compare PiezoRx®'s steps and intensity related physical activity to physiological assessments. 3) To assess the utility of the PiezoRx® in a subsample of participants. Thirty-nine participants consisting of 28 females aged 54.9±10.6 (33-74) years and 11 males aged 63.9±10.9 (44-80) years wore the PiezoRx® physical activity monitor and the ActiGraph® accelerometer for one full week and completed a physical assessment. A subsample (n=24) wore the PiezoRx® for an additional two weeks and completed a questionnaire regarding usability. The PiezoRx® had strong correlations to the ActiGraph® for step count (r=0.88; p<0.001), moderate-vigorous physical activity (MVPA) (r=0.70; p<0.001), and sedentary activity (r=0.93; p<0.001) in the 1-week monitoring period. The PiezoRx®'s steps/day and MVPA/week were negatively correlated (p<0.001) to body mass index and waist circumference, and positively correlated (p<0.05) to aerobic fitness, pushups, and 30 second sit-to-stand. Within the subsample who completed the additional two-week monitoring, 75% of participants reported that the PiezoRx® increased their physical activity. In conclusion, The PiezoRx® appears to be a valid measure of free-living PA compared to accelerometry. Because of the correlations of the PiezoRx®'s steps/day and MVPA/week to anthropometric, musculoskeletal and aerobic fitness these PA measures may be valuable objective surrogates to use in clinical or professional practice for physical health.
Prolonged sitting reduces lower-limb resistance vessel function (RVF). In contrast, increasing levels of aerobic fitness enhances lower-limb RVF. However, it is unknown if higher aerobic fitness can protect against prolonged sitting-induced declines in RVF. PURPOSE: To investigate the impact of aerobic fitness on sitting-induced reductions in lower-limb RVF. METHODS: In 8 healthy young adults (6♀, 22 ± 2 years), aerobic fitness was assessed via indirect calorimetry as the relative peak oxygen consumption (V̇O2peak) attained from a graded, maximal cycling test (37.5 ± 8.7 mlO2/kg/min, range: 27.7-50.2 mlO2/kg/min). Popliteal blood flow (mL/min) and beat-by-beat arterial pressure (mmHg) were recorded via duplex ultrasonography and finger photoplethysmography, respectively. Popliteal vascular conductance (PVC, mL/min/mmHg) was calculated as blood flow/mean arterial pressure. Lower-limb RVF was assessed in the seated posture and quantified as the peak PVC and PVC area under the curve (PVCAUC, first minute of hyperemia) responses to 5-min of distal cuff-induced ischemia. The lower-limb RVF assessment was performed before and after a ~ 3-hour bout of uninterrupted sitting. RESULTS: Peak PVC decreased following sitting (659 ± 125 to 452 ± 170 mL/min/mmHg, P = 0.05), while PVCAUC remained unchanged (105 ± 35 versus 87 ± 21 mL/mmHg, P = 0.17). Relative V̇O2peak was not associated with Pre-Sitting Peak PVC (R = 0.226, P = 0.626) or PVCAUC (R = -0.022, P = 0.963). Relative V̇O2peak was also not associated with sitting-induced reductions in Peak PVC (R = 0.269, P = 0.560). CONCLUSIONS: The post-sitting reductions in Peak PVC support previous work demonstrating that prolonged uninterrupted sitting negatively impacts lower-limb RVF. In contrast, prolonged sitting did not alter the PVCAUC response. This suggests that Peak PVC responses may provide a more sensitive index of sitting-induced declines in RVF. In young, healthy individuals, aerobic fitness did not impact baseline or sitting-induced reductions in lower-limb RVF.
