Brachial artery endothelial function is unchanged after acute sprint interval exercise in sedentary men and women

How Does the Dose and Type of Exercise Impact Acute Cardiovascular Function in Healthy Individuals?

During aerobic exercise, the cardiovascular system is tasked with delivering oxygen to active skeletal muscle via muscle blood flow while regulating mean arterial blood pressure. The impact of aerobic exercise on acute cardiovascular function may be modulated by the dose and type of exercise. Acutely, dose is the product of exercise intensity and time, whereas exercise type may refer to common aerobic modalities like cycling, running, swimming, or rowing. Each modality is unique for its medium of completion as well as the implications on blood flow arising from the position of active muscle mass relative to heart level. The purpose of this review was to address how an acute exercise dose influences cardiovascular function between prominent aerobic exercise modalities in healthy individuals. Across all modalities, all doses may transiently reduce both left and right ventricular systolic and diastolic function as well as both macro- and microvascular function. However, accurately quantifying and comparing exercise dose across the literature is challenging due to methodologic differences in exercise prescription and the cardiovascular demands imposed by differing modalities of exercise. Furthermore, the potential confounding influence of cardiovascular drift alongside variations in age, the composition of cohorts with respect to biological sex, and timing of cardiovascular measures further complicates interpretation. Future work should focus on exercise intensity prescription according to modality-specific physiologic thresholds to provide comparable doses. This approach may serve to standardize the physiologic stimulus and allow for objective assessments to be compared with confidence.

The Effects of Previous Amenorrhea on Endothelial and Vascular Function

Introduction: Endogenous estrogen has a protective cardiovascular effect. Estrogen loss, such as during menopause and amenorrhea, results in stiffer vessels and endothelial dysfunction. It is unknown if reversing amenorrhea and regaining a regular menstrual cycle leads to the restoration of cardiovascular function. Methods: Sixteen women were divided into groups: eumenorrheic (n = 10; 23 ± 3 years) women who had a consistent menstrual cycle and amenorrheic (n = 6; 22 ± 1 year) women who previously were without their menstrual cycle for at least 6 consecutive months. Endothelial function, arterial stiffness, and brachial and aortic blood pressure were assessed. Results: There were no differences between groups in endothelial function or arterial stiffness measures. The previously amenorrheic group displayed lower brachial systolic and mean pressures and aortic systolic, diastolic, and mean pressures. When controlling for physical activity, only central pressure remained significantly lower in the amenorrheic group. Conclusions: Previous amenorrhea in young women does not result in long-term cardiovascular consequences in arterial and endothelial function measures assuming regular menstruation resumes. Physical activity shows a blood pressure-lowering effect in the peripheral arteries, while the previously amenorrheic group demonstrated lower central pressures, independent of physical activity.

Impact of Sex and Exercise on Femoral Artery Function: More Favorable Adaptation in Male Rats

Blood flow increases in arteries of the skeletal muscles involved in active work. Our aim was to investigate the gender differences as a result of adaptation to sport in the femoral arteries. Vascular reactivity and histology of animals were compared following a 12-week swimming training. Animals were divided into sedentary male (MS), trained male (MTr), sedentary female (FS), and trained female (FTr) groups. Isolated femoral artery rings were examined by wire myography. Contraction induced by phenylephrine (Phe) did not differ between the four groups. The contractile ability in the presence of indomethacin (INDO) was decreased in both sedentary groups. However, we found a specific cyclooxygenase-2 (COX-2) role only in FS rats. After exercise training, we observed increased vasoconstriction in both sexes, when nitro-L-arginine methyl ester (L-NAME) was present. The COX-dependent vasoconstriction effect disappeared in MTr animals, and the COX-2-dependent vasoconstriction effect disappeared in FTr ones. Relaxation was reduced significantly, when L-NAME was present in MTr animals compared to in FTr rats. The training was associated with greater endothelial nitric oxide synthase (eNOS) protein expression in males, but not in females. The present study proves that there are gender differences regarding adaptation mechanisms of musculocutaneous arteries to sports training. In males, relaxation reserve capacity was markedly elevated compared to in females.

Post-exercise endothelial function is not associated with extracellular vesicle release in healthy young males

Acute exercise can result in temporary decrease in endothelial functions, which may represent a transient period of risk. Numerous mechanisms underpinning these responses included release of extracellular vesicles (EVs) derived from apoptotic or activated endothelial cells and platelets. This study aims to compare the time course of endothelial responses to moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) and the associations with EV release. Eighteen young healthy males (age: 22.6 ± 3.7 years, BMI: 25.6 ± 2.5 m²/kg, and VO_2peak: 38.6 ± 6.5 mL/kg/min) completed two randomly assigned exercises: HIIE (10 × 1 min-@-90% heart rate reserve (HRR) and 1 min passive recovery) and MICE (30 min-@-70% HRR) on a cycle ergometer. Flow-mediated dilation (FMD) was used to assess endothelial function and blood samples were collected to evaluate endothelial cell-derived EV (CD62E⁺) and platelet-derived EV (CD41a⁺), 10, 60, and 120 min before and after exercise. There were similar increases but different time courses (P = 0.017) in FMD (increased 10 min post-HIIE, P < 0.0001 and 60 min post-MICE, P = 0.038). CD62E⁺ remained unchanged (P = 0.530), whereas overall CD41a⁺ release was reduced 60 min post-exercise (P = 0.040). FMD was not associated with EV absolute release or change (P > 0.05). Acute exercise resulted in similar improvements, but different time course in FMD following either exercise. Whilst EVs were not associated with FMD, the reduction in platelet-derived EVs may represent a protective mechanism following acute exercise.

Evidence of reduced peripheral microvascular function in young Black women across the menstrual cycle

Black women (BLW) have a higher prevalence of cardiovascular disease (CVD) morbidity and mortality compared with White women (WHW). A racial disparity in CVD risk has been identified early in life as young adult BLW demonstrate attenuated vascular function compared with WHW. Previous studies comparing vascular function between premenopausal WHW and BLW have been limited to the early follicular (EF) phase of the menstrual cycle, which may not reflect their vascular function during other menstrual phases. Therefore, we evaluated peripheral microvascular function in premenopausal WHW and BLW using passive leg movement (PLM) during three menstrual phases: EF, ovulation (OV), and mid-luteal (ML). We hypothesized that microvascular function would be augmented during the OV and ML phases compared with the EF phase in both groups, but would be attenuated in BLW compared with WHW at all three phases. PLM was performed on 26 apparently healthy premenopausal women not using hormonal contraceptives: 15 WHW (23 ± 3 yr), 11 BLW (24 ± 5 yr). There was a main effect of race on the overall change in leg blood flow (ΔLBF) (P = 0.01) and leg blood flow area under the curve (LBF AUC) (P = 0.02), such that LBF was lower in BLW. However, there was no effect of phase on ΔLBF (P = 0.69) or LBF AUC (P = 0.65), nor an interaction between race and phase on ΔLBF (P = 0.37) or LBF AUC (P = 0.75). Despite peripheral microvascular function being unchanged across the menstrual cycle, a racial disparity was apparent as microvascular function was attenuated in BLW compared with WHW across the menstrual cycle.NEW & NOTEWORTHY This is the first study to compare peripheral microvascular function between young, otherwise healthy Black women and White women at multiple phases of the menstrual cycle. Our novel findings demonstrate a significant effect of race on peripheral microvascular function such that Black women exhibit significant attenuations in microvascular function across the menstrual cycle compared with White women.

There are no differences in brachial artery endothelial shear stress and blood flow patterns between males and females during exercise

Premenopausal females have a lower cardiovascular risk than males. Sex differences on exercise-induced endothelial shear stress (ESS) and blood flow patterns may explain part of this risk reduction. The purpose of this cross-sectional study was to determine the differences in brachial artery exercise-induced ESS and blood flow patterns between males and females. Thirty subjects (13 females) were recruited to perform a three-workload steady-state exercise test based on blood lactate levels (i.e. <2.0, 2.0-4.0, >4.0 mmol/l). ESS and blood flow patterns were estimated at rest and during each workload using Womersley's approximation and Reynolds number, respectively. Both males and females showed an exercise intensity-dependent increase in antegrade and retrograde ESS. There was no significant sex effect or interaction for antegrade ESS (F_{(1, 30)}  = 0.715, p = 0.405 and F_{(1·672, 60)}  = 1.511, p = 0.232, respectively) or retrograde ESS (F_{(1, 30)}  = 0.794, p = 0.380 and F_{(1·810, 60)}  = 1.022, p = 0.361, respectively). Additionally, antegrade blood flow was turbulent during all bouts of exercise while retrograde blood flow became disturbed at moderate and high exercise intensities in both groups. There are no differences in exercise-induced ESS and blood flow patterns between males and females when the exercise load is equivalent. This suggests that the vascular benefits of exercise training are similar in both sexes from a haemodynamic standpoint.

Transient Reduction of FMD-Response and L-Arginine Accompanied by Increased Levels of E-Selectin, VCAM, and ICAM after Prolonged Strenuous Exercise

We assessed endothelial function by flow-mediated dilatation (FMD), levels of the NO-precursor L-arginine, and markers of endothelial inflammation before, at the finish line, and one week after the Norseman Xtreme triathlon. The race is an Ironman distance triathlon with a total elevation of 5200 m. Nine male participants were included. They completed the race in 14.5 (13.4–15.3) h. FMD was significantly reduced to 3.1 (2.1–5.0)% dilatation compared to 8.7 (8.2–9.3)% dilatation before the race (p < 0.05) and was normalized one week after the race. L-arginine showed significantly reduced levels at the finish line (p < 0.05) but was normalized one week after the race. Markers of endothelial inflammation E-Selectin, VCAM-1, and ICAM-1 all showed a pattern with increased values at the finish line compared to before the race (all p < 0.05), with normalization one week after the race. In conclusion, we found acutely reduced FMD with reduced L-arginine levels and increased E-Selectin, VCAM-1, and ICAM-1 immediately after the Norseman Xtreme triathlon. Our findings indicate a transient reduced endothelial function, measured by the FMD-response, after prolonged strenuous exercise that could be explained by reduced NO-precursor L-arginine levels and increased endothelial inflammation.

Effects of Catheterization on Artery Function and Health: When Should Patients Start Exercising Following Their Coronary Intervention?

Coronary artery disease (CAD) is a leading cause of death worldwide, and percutaneous transluminal coronary angiography (PTCA) and/or percutaneous coronary intervention (PCI; angioplasty) are commonly used to diagnose and/or treat the obstructed coronaries. Exercise-based rehabilitation is recommended for all CAD patients; however, most guidelines do not specify when exercise training should commence following PTCA and/or PCI. Catheterization can result in arterial dysfunction and acute injury, and given the fact that exercise, particularly at higher intensities, is associated with elevated inflammatory and oxidative stress, endothelial dysfunction and a pro-thrombotic milieu, performing exercise post-PTCA/PCI may transiently elevate the risk of cardiac events. This review aims to summarize extant literature relating to the impacts of coronary interventions on arterial function, including the time-course of recovery and the potential deleterious and/or beneficial impacts of acute versus long-term exercise. The current literature suggests that arterial dysfunction induced by catheterization recovers 4-12 weeks following catheterization. This review proposes that a period of relative arterial vulnerability may exist and exercise during this period may contribute to elevated event susceptibility. We therefore suggest that CAD patients start an exercise training programme between 2 and 4 weeks post-PCI, recognizing that the literature suggest there is a 'grey area' for functional recovery between 2 and 12 weeks post-catheterization. The timing of exercise onset should take into consideration the individual characteristics of patients (age, severity of disease, comorbidities) and the intensity, frequency and duration of the exercise prescription.