Vascular endothelium-derived factors and arterial stiffness in strength- and endurance-trained men

Aerobic exercise training increases plasma Klotho levels and reduces arterial stiffness in postmenopausal women

The Klotho gene is a suppressor of the aging phenomena, and the secretion as well as the circulation of Klotho proteins decrease with aging. Although habitual exercise has antiaging effects (e.g., a decrease in arterial stiffness), the relationship between Klotho and habitual exercise remains unclear. In the present study, we investigated the effect of habitual exercise on Klotho, with a particular focus on arterial stiffness. First, we examined the correlation between plasma Klotho concentration and arterial stiffness (carotid artery compliance and β-stiffness index) or aerobic exercise capacity [oxygen uptake at ventilatory threshold (VT)] in 69 healthy, postmenopausal women (50-76 years old) by conducting a cross-sectional study. Second, we tested the effects of aerobic exercise training on plasma Klotho concentrations and arterial stiffness. A total of 19 healthy, postmenopausal women (50-76 years old) were divided into two groups: control group and exercise group. The exercise group completed 12 wk of moderate aerobic exercise training. In the cross-sectional study, plasma Klotho concentrations positively correlated with carotid artery compliance and VT and negatively correlated with the β-stiffness index. In the interventional study, aerobic exercise training increased plasma Klotho concentrations and carotid artery compliance and decreased the β-stiffness index. Moreover, the changes in plasma Klotho concentration and arterial stiffness were found to be correlated. These results suggest a possible role for secreted Klotho in the exercise-induced modulation of arterial stiffness.

Peak stepping cadence is associated with leg vascular compliance in young adults

OBJECTIVES

To test the hypothesis that volume or intensity of daily ambulatory activity would associate with greater large artery compliance in healthy untrained adults.

DESIGN

Cross-sectional study.

METHODS

Forty-five recreationally active young adults (22 ± 3 yr, 51% women) wore an accelerometer for 5.3 ± 1.3 days for determination of average daily steps (volume) and 30-min peak stepping cadence (intensity; average steps per min for the 30 highest min in a day). Arterial compliance of the common carotid artery, superficial femoral artery (SFA), and popliteal artery was estimated using Doppler ultrasound. Data were analyzed using correlational analysis and analysis of covariance.

RESULTS

Average daily steps and peak stepping cadence was 8957 ± 3422 steps per day and 97 ± 24 steps per min, respectively. Weight was the main independent predictor of daily steps (r(2) = 0.13, p = 0.01) and peak stepping cadence (r(2) = 0.17, p<0.01). After adjusting ambulatory activity for weight, SFA compliance was positively correlated with peak stepping cadence (r = 0.53, p<0.01) but not with daily steps (r = 0.23, p > 0.05). No other correlations were found between ambulatory activity and carotid or popliteal artery compliance (p>0.05). Adults with peak stepping cadence ≥ 102 steps per min had greater carotid (1.26 ± 0.08 vs. 1.57 ± 0.09 mm(2) kPa(-1); p = 0.01) and SFA compliance (0.43 ± 0.03 vs. 0.54 ± 0.03 mm(2) kPa(-1); p = 0.04) than adults with lower stepping cadence.

CONCLUSIONS

"Brisk" stepping cadence during daily ambulation is associated with greater leg vascular compliance. These results support the promotion of accumulating 30 min of "brisk" walking per day as a strategy to improve vascular health.

Thoracic aorta vasoreactivity in rats under exhaustive exercise: effects of Lycium barbarum polysaccharides supplementation

Background

Reduced arterial compliance is associated with an increased rate of morbidity and mortality in cardiovascular disease. Exercise is beneficial for compromised arterial compliance. However, the beneficial effects of exercise are lost with exhaustion. Lycium barbarum L. has been used in China for centuries to maintain good health. In this regard, the primary purpose of this study was to characterize the effects of the polysaccharides from Lycium barbarum (LBPs) on arterial compliance during exhaustive exercise.

Methods

A four-week swimming exercise program was designed for rats, and the blood levels of malondialdehyde (MDA), super oxide dismutase (SOD), nitric oxide(NO) and heat shock protein 70(HSP70) were detected. The tension of aorta rings was measured to evaluate the response of rats on noradrenaline (NA)-induced contractions.

Results

The rats administered LBPs showed longer swimming time until exhaustion than the control group of rats. Exercise-induced MDA elevation was repressed by LBPs supplementation. The LBPs-supplemented rats displayed a significant increase of SOD, NO, HSP70 than the non-supplemented rats. Additionally, LBPs significantly up-regulated the expression of eNOS and improved the endothelium-dependent vasodilatation of the aorta ring.

Conclusion

Our study proved that LBPs administration significantly inhibited the oxidative stress, and improved the arterial compliance.

Ultra-endurance sports have no negative impact on indices of arterial stiffness

PURPOSE

Marathon running has been linked with higher arterial stiffness. Blood pressure is a major contributor to pulse wave velocity (PWV). We examined indices of arterial stiffness with a blood pressure-independent method in marathon runners and ultra-endurance athletes.

METHODS

Male normotensive amateur runners were allocated to three groups according to former participation in competitions: group I (recreational athletes), group II (marathon runners) and group III (ultra-endurance athletes). Indices of arterial stiffness were measured with a non-invasive device (VaSera VS-1500N, Fukuda Denshi, Japan) to determine the cardio-ankle vascular index (CAVI, primary endpoint) and brachial-ankle PWV (baPWV). Lifetime training hours were calculated. Cumulative competitions were expressed as marathon equivalents. Linear regression analysis was performed to determine predictors for CAVI and baPWV.

RESULTS

Measurements of arterial stiffness were performed in 51 subjects (mean age 44.6 ± 1.2 years): group I (n = 16), group II (n = 19) and group III (n = 16). No between-group differences existed in age, anthropometric characteristics and resting BP. CAVI and baPWV were comparable between all groups (P = 0.604 and P = 0.947, respectively). In linear regression analysis, age was the only independent predictor for CAVI (R(2) = 0.239, β = 0.455, P = 0.001). Systolic BP was significantly associated with baPWV (R(2) = 0.225, β = 0.403, P = 0.004).

CONCLUSIONS

In middle-aged normotensive athletes marathon running and ultra-endurance sports had no negative impact on arterial stiffness.

Comparison of brachial artery vasoreactivity in elite power athletes and age-matched controls

Elite endurance athletes typically have larger arteries contributing to greater skeletal muscle blood flow, oxygen and nutrient delivery and improved physical performance. Few studies have examined structural and functional properties of arteries in power athletes.

PURPOSE

To compare the size and vasoreactivity of the brachial artery of elite power athletes to age-matched controls. It was hypothesized brachial artery diameters of athletes would be larger, have less vasodilation in response to cuff occlusion, but more constriction after a cold pressor test than age-matched controls.

METHODS

Eight elite power athletes (age = 23 ± 2 years) and ten controls (age = 22 ± 1 yrs) were studied. High-resolution ultrasonography was used to assess brachial artery diameters at rest and following 5 minutes of forearm occlusion (Brachial Artery Flow Mediated Dilation = BAFMD) and a cold pressor test (CPT). Basic fitness measures included a handgrip test and 3-minute step test.

RESULTS

Brachial arteries of athletes were larger (Athletes 5.39 ± 1.51 vs.

CONTROLS

3.73 ± 0.71 mm, p<0.05), had greater vasodilatory (BAFMD%: Athletes: 8.21 ± 1.78 vs.

CONTROLS

5.69 ± 1.56%) and constrictor (CPT %: Athletes: -2.95 ± 1.07 vs.

CONTROLS

-1.20 ± 0.48%) responses, compared to controls. Vascular operating range (VOR = Peak dilation+Peak Constriction) was also greater in athletes (VOR: Athletes: 0.55 ± 0.15 vs.

CONTROLS

0.25 ± 0.18 mm, p<0.05). Athletes had superior handgrip strength (Athletes: 55.92 ± 17.06 vs.

CONTROLS

36.77 ± 17.06 kg, p<0.05) but similar heart rate responses at peak (Athletes: 123 ± 16 vs.

CONTROLS

130 ± 25 bpm, p>0.05) and 1 minute recovery (Athletes: 88 ± 21 vs.

CONTROLS

98 ± 26 bpm, p>0.05) following the step test.

CONCLUSION

Elite power athletes have larger brachial arteries, and greater vasoreactivity (greater vasodilatory and constrictor responses) than age-matched controls, contributing to a significantly greater VOR. These data extend the existence of an 'athlete's artery' as previously shown for elite endurance athletes to elite power athletes, and presents a hypothetical explanation for the functional significance of the 'power athlete's artery'.

Comprehensive assessment of biventricular function and aortic stiffness in athletes with different forms of training by three-dimensional echocardiography and strain imaging

AIMS

Previous studies have shown distinct models of cardiac adaptations to the training in master athletes and different effects of endurance and strength-training on cardiovascular function. We attempted to assess left-ventricular (LV) function, aortic (Ao) function, and right-ventricular (RV) function in athletes with different forms of training by using three-dimensional (3D) echocardiography, tissue Doppler imaging (TDI) and speckle-tracking imaging (STI).

METHODS AND RESULTS

We examined 35 male marathon runners (endurance-trained athletes, ETA), 35 powerlifting athletes (strength-trained athletes, STA), 35 martial arts athletes (mixed-trained athletes, MTA), and 35 sedentary untrained healthy men (controls, CTR). Two-dimensional and three-dimensional echocardiography were performed for the assessment of LV and RV systolic/diastolic function. LV and RV longitudinal strain (LS) and LV torsion (LVtor) were determined using STI (EchoPAC BT11, GE-Ultrasound). Maximum velocity of systolic wall expansion peaks (AoSvel) was determined using TDI. ETA experienced LV eccentric hypertrophy with increased 3D LV end-diastolic volume and mass and significant increase in peak systolic apical rotation and LVtor. In all groups of athletes, RV-LS was reduced at rest and improved after exercise. AoSvel was significantly increased in ETA and MTA and significantly decreased in STA compared with CTR. There were good correlations between LV remodelling and aortic stiffness values. Multivariate analysis showed aortic wall velocities to be independently related to LV mass index.

CONCLUSION

In strength-trained, endurance-trained, and mixed-trained athletes, ventricular and vascular response assessed by 3DE, TDI, and STI underlies different adaptations of LV, RV, and aortic indexes.

Blood flow restricted exercise and vascular function

It is established that regular aerobic training improves vascular function, for example, endothelium-dependent vasodilatation and arterial stiffness or compliance and thereby constitutes a preventative measure against cardiovascular disease. In contrast, high-intensity resistance training impairs vascular function, while the influence of moderate-intensity resistance training on vascular function is still controversial. However, aerobic training is insufficient to inhibit loss in muscular strength with advancing age; thus, resistance training is recommended to prevent sarcopenia. Recently, several lines of study have provided compelling data showing that exercise and training with blood flow restriction (BFR) leads to muscle hypertrophy and strength increase. As such, BFR training might be a novel means of overcoming the contradiction between aerobic and high-intensity resistance training. Although it is not enough evidence to obtain consensus about impact of BFR training on vascular function, available evidences suggested that BFR training did not change coagulation factors and arterial compliance though with inconsistence results in endothelial function. This paper is a review of the literature on the impact of BFR exercise and training on vascular function, such as endothelial function, arterial compliance, or other potential factors in comparison with those of aerobic and resistance training.

Effect of perindopril on pulse-wave velocity and endothelin-1 in black hypertensive patients

INTRODUCTION

We investigated the effect of perindopril on pulse-wave velocity (as indicator of arterial elasticity) and endothelin-1 (ET-1) levels in black hypertensive patients.

METHODS

Forty-four newly diagnosed hypertensive patients who received 4 mg perindopril daily were monitored for nine months. Pulse-wave velocity (PWV) was measured noninvasively along the carotid-femoral arterial segment (high elastic content) and the brachial-ulnar segment (low elastic content).

RESULTS

There was a significant increase in arterial elasticity, as indicated by a slower PWV in the carotid-femoral segment of the treatment group, from 11.6 to 7.5 m/s after nine months. The PWV of the treatment group (7.5 m/s) after nine months was lower than that of the healthy volunteer group (8.2 m/s) but it was not statistically significant. No correlation between ET-1 and PWV could be found.

CONCLUSION

In addition to its blood pressure-lowering effect, our study confirmed the improvement in arterial elasticity in patients on perindopril therapy, without involvement of ET-1.

Effects of high-intensity and blood flow-restricted low-intensity resistance training on carotid arterial compliance: role of blood pressure during training sessions

We examined the effects of high-intensity resistance training (HIT) and low-intensity blood flow-restricted (LI-BFR) resistance training on carotid arterial compliance. Nineteen young men were randomly divided into HIT (n = 9) or LI-BFR (n = 10) groups. The HIT and LI-BFR groups performed 75 and 30 %, respectively, of one-repetition maximum (1-RM) bench press exercise, 3 days per week for 6 weeks. During the training sessions, the LI-BFR group wore elastic cuffs around the most proximal region of both arms. Muscle cross-sectional area (CSA), 1-RM strength, and carotid arterial compliance were measured before and 3 days after the final training session. Acute changes in systolic arterial pressure (SAP), plasma endothelin-1 (ET-1), nitrite/nitrate (NOx), and noradrenalin concentrations were also measured during and after a bout of training session. The training led to significant increases (P < 0.01) in bench press 1-RM and arm and chest muscle CSA in the two training groups. Carotid arterial compliance decreased significantly (P < 0.05) in the HIT group, but not in the LI-BFR group. There was a significant correlation (r = -0.533, P < 0.05) between the change in carotid arterial compliance and the acute change in SAP during training sessions; however, ET-1 and NOx did not correlate with carotid arterial compliance. Our results suggest that muscle CSA and strength increased following 6 weeks of both HIT and LI-BFR training. However, carotid arterial compliance decreased in only the HIT group, and the changes were correlated with SAP elevations during exercise sessions.

Habitual rowing exercise is associated with high physical fitness without affecting arterial stiffness in older men

The present study elucidated the effects of habitual rowing exercise on arterial stiffness and plasma levels of the vasoconstrictor endothelin-1 and the vasodilator nitric oxide (NO) in older men. Eleven rowers (68.0 ± 1.6 years) and 11 sedentary control older men (64.9 ± 1.1 years) were studied. Peak oxygen uptake (36.0 ± 1.7 vs. 27.7 ±1.9 ml · kg(-1) · min(-1)), leg press power (1346 ± 99 vs. 1077 ± 68 W), and HDL-cholesterol (75 ± 5 vs. 58 ±3 mg · ml(-1)) were higher and triglyceride (78 ± 9 vs. 120 ± 14 mg · ml(-1)) was lower in rowers than in control participants (all P < 0.05). Arterial stiffness indices (carotid β-stiffness and cardio-ankle vascular index) and plasma endothelin-1 and NOx (nitrite + nitrate) levels did not differ between the two groups. These results suggest that habitual rowing exercise in older men is associated with high muscle power and aerobic capacity, and favourable blood lipid profile without affecting arterial stiffness or plasma levels of endotheline-1 and NO.

Effects of acute resistance exercise on arterial stiffness in young men

Background and Objectives

Increased central arterial stiffness is an emerging risk factor for cardiovascular disease. Acute aerobic exercise reduces arterial stiffness, while acute resistance exercise may increase arterial stiffness, but this is not a universal finding. We tested whether an acute resistance exercise program was associated with an increase in arterial stiffness in healthy young men.

Subjects and Methods

Thirteen healthy subjects were studied under parallel experimental conditions on 2 separate days. The order of experiments was randomized between resistance exercise (8 resistance exercises at 60% of 1 repeated maximal) and sham control (seated rest in the exercise room). Carotid-femoral pulse wave velocity (PWV) and aortic augmentation index as indices of aortic stiffness were measured using applanation tonometry. Measurements were made at baseline before treatments, 20 minutes, and 40 minutes after treatments (resistance exercise and sham control).

Results

There was no difference in resting heart rate or in arterial stiffness between the two experimental conditions at baseline. At 20 minutes after resistance exercise, heart rate, carotid-femoral PWV and augmentation index@75(%) were significantly increased in the resistance exercise group compared with the sham control (p<0.05). Brachial blood pressure, central blood pressure and pulse pressure were not significantly increased after resistance exercise.

Conclusion

An acute resistance exercise program can increase arterial stiffness in young healthy men. Further studies are needed to clarify the effects of long-term resistance training on arterial stiffness.

Additive beneficial effects of lactotripeptides and aerobic exercise on arterial compliance in postmenopausal women

Central arterial compliance plays an important role in the functional abilities of the vasculature. Two active tripeptides, valine-proline-proline and isoleucine-proline-proline, were isolated from sour milk and were referred to as lactotripeptides (LTP). Because LTP appears to act as an angiotensin-converting enzyme inhibitor, it is plausible to hypothesize that LTP improves arterial compliance. We determined the effects of LTP ingestion alone or in combination with regular aerobic exercise on arterial compliance. A total of 55 postmenopausal women (50-65 yr old) were randomly divided into four groups: placebo, LTP, exercise and placebo (Ex + placebo), or exercise and LTP (Ex + LTP). LTP or placebo was administered orally for 8 wk. The exercise groups completed an 8-wk moderate aerobic exercise intervention. There were no differences in baseline arterial compliance and most other key dependent variables among the groups. Carotid arterial compliance increased significantly in the LTP (0.93 + or - 0.07 vs. 0.99 + or - 0.08 mm(2)/mmHg x 10(-1)), Ex + placebo (0.92 + or - 0.04 vs. 1.00 + or - 0.05 mm(2)/mmHg x 10(-1)), and Ex + LTP groups (0.86 + or - 0.06 vs. 1.00 + or - 0.06 mm(2)/mmHg x 10(-1)), whereas no such changes were observed in the placebo control group (0.86 + or - 0.06 vs. 0.85 + or - 0.07 mm(2)/mmHg x 10(-1)). The magnitude of increases in carotid arterial compliance was significantly greater in the Ex + LTP group (19 + or - 4%) than in other groups. The improvements in arterial compliance with LTP were associated with the corresponding reductions in arterial blood pressure and plasma angiotensin II concentrations. We concluded that LTP ingestion improves carotid arterial compliance and that the combination of LTP ingestion and regular exercise is additive and synergistic in improving arterial compliance in postmenopausal women.

Regular endurance exercise in young men increases arterial baroreflex sensitivity through neural alteration of baroreflex arc

Endurance exercise training increases arterial baroreflex sensitivity that corresponds to alteration in vessel wall compliance of the carotid artery in elderly men. Here, we examined whether regular endurance exercise increases arterial baroreflex sensitivity through neural alteration of the baroreflex arc in young men. We assessed arterial baroreflex sensitivity in eight sedentary men (age 24 ± 1 yr) and nine men trained in endurance exercise (age 23 ± 1 yr) during phase IV of the Valsalva maneuver [systolic arterial blood pressure (SAP)–R-R interval relationship]. Arterial baroreflex sensitivity was further analyzed by dividing the mechanical component [SAP–end-systolic carotid lumen diameter relationship (ultrasonography)] and the neural component (end-systolic carotid lumen diameter–R-R interval relationship). Carotid arterial compliance was determined using B-mode ultrasound and arterial applanation tonometry on the common carotid artery. Arterial baroreflex sensitivity and its neural component were greater in the exercise-trained group ( P < 0.05). In contrast, carotid arterial compliance and the mechanical component of arterial baroreflex sensitivity did not differ between groups. These results suggest that regular endurance exercise in young men increases arterial baroreflex sensitivity through changes in the neural component of the baroreflex arc and not through alterations in vessel wall compliance of the carotid artery.

Arterial stiffness acutely decreases after whole-body vibration in humans

BACKGROUND

Increased arterial stiffness is a well-established cardiovascular risk factor. Mechanical stimuli to artery, such as compression, elicit vasodilation and acutely decrease arterial stiffness. As whole-body vibration (WBV)-induced oscillation is propagated at least to lumbar spine, WBV mechanically stimulates abdominal and leg arteries and may decrease arterial stiffness. WBV is feasible in vulnerable and immobilized humans. Therefore, it is worthwhile to explore the possibility of WBV as a valuable adjunct to exercise training.

AIM

The aim of this study was to investigate the acute effects of WBV on arterial stiffness.

METHODS

Ten healthy men performed WBV and control (CON) trials on separate days. The WBV session consisted of 10 sets of vibration (frequency, 26 Hz) for 60 s with an inter-set rest period of 60 s. Subjects maintained a static squat position with knees bent on a platform. In the CON trial, WBV stimulation was not imposed. Blood pressure, heart rate and brachial-ankle pulse wave velocity (baPWV), an index of arterial stiffness, were measured before and 20, 40 and 60 min after both trials.

RESULTS AND CONCLUSION

Heart rate and blood pressure did not change from baseline after both trials. Although baPWV did not change in the CON trial (baseline vs. after 20, 40 and 60 min; 1144 +/- 35 vs. 1164 +/- 41, 1142 +/- 39, and 1148 +/- 34 cm s(-1)), baPWV decreased 20 and 40 min after the WBV trial and recovered to baseline 60 min after the trial (1137 +/- 28 vs. 1107 +/- 30, 1108 +/- 28, and 1128 +/- 25 cm s(-1)). These results suggest that WBV acutely decreases arterial stiffness.

Arterial elastic property in young endurance and resistance-trained women

In men, regular aerobic exercise increases central arterial elasticity, but it is decreased by resistance training. We determined the relation between the type of exercise training and arterial elasticity in healthy young women: 26 healthy young women who were sedentary (CO, n = 9), endurance-trained (ET, n = 9), and resistance-trained (RT, n = 8) groups. We determined the carotid arterial compliance and distensibility coefficient (simultaneous ultrasound and applanation tonometry), VO(2max), and 1RM (bench press and leg extension). The VO(2max) in the ET groups was higher than in the CO and RT groups. Both 1RM were higher in the RT groups than in the CO and ET groups. No significant difference was found in the carotid artery compliance and distensibility coefficient among the ET, RT, and CO groups. These results underscore the difficulty in detecting a change in arterial elasticity in young female athletes using the type of exercise training by which it is shown in young men.

Characterization of Hemodynamics in Patients with Idiopathic and Thromboembolic Pulmonary Hypertension

Demographic and hemodynamic data from patients with idiopathic pulmonary arterial hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH) have not been systematically characterized to identify differences related to gender, age, race, disease severity, and drug response. Our goal was to define the distribution and relation of IPAH and CTEPH based on these criteria. Hemodynamic and demographic data from 242 IPAH patients and 90 CTEPH patients were collected and compared. IPAH incidence was greater in women, but men had a higher basal mean pulmonary arterial pressure (mPAP). mPAP was comparable among all IPAH ethnic groups. IPAH patients with no history of fenfluramine-phentermine use had a higher mPAP than users. Exercise-induced IPAH was apparent in 14.5% of IPAH patients. Only 9% of IPAH patients responded to inhaled nitric oxide with a ≥20% decrease in mPAP. Compared to CTEPH patients, mPAP was greater but average age of diagnosis was lower in IPAH patients. mPAP negatively correlated with age of diagnosis in IPAH patients only. These results indicate that elevated CO is not the main determinant of mPAP in both IPAH and CTEPH patients. However, the two patient groups differ in terms of their demographic and hemodynamic distributions, and according to the correlation between mPAP and other clinical hemodynamics and demographics.

Acute exercise increases systemic arterial compliance after 6-month exercise training in older women

High physical activity or aerobic exercise training increases central arterial distensibility in older humans. However, the effect of a single bout of exercise on central arterial distensibility in older humans is unknown. Furthermore, the effect of exercise training on central arterial distensibility during exercise is unclear. We investigated whether systemic arterial compliance (SAC) changes after acute exercise in older humans, and, if so, whether this change in SAC is enhanced by aerobic exercise training. Seven untrained older women (61-69 years old) participated in a 6-month exercise intervention study. We measured SAC after acute exercise (cycling exercise at 80% of their individual ventilatory threshold for 30 min) before and after 6 months of aerobic exercise training. After exercise training, the individual ventilatory threshold was significantly increased. In addition, both the SAC at rest and that 30 min after acute exercise were significantly increased after the exercise training program. Before exercise training, there was no significant increase in SAC after acute exercise, whereas, after exercise training, the SAC was significantly increased 30 min after acute exercise. The present study suggests that, after aerobic exercise training, SAC increases after acute exercise in older humans, and that the SAC at rest and after acute exercise is enhanced by aerobic exercise training, thereby causing an effective adaptation in increase in cardiac output during exercise.

Systemic arterial compliance, systemic vascular resistance, and effective arterial elastance during exercise in endurance-trained men

Systemic arterial compliance (C) and vascular resistance (R) regulate effective arterial elastance (Ea), an index of artery load. Increases in Ea during exercise are due primarily to reductions of C and maintain optimal ventricular-arterial coupling. Because C at rest and left ventricular functional reserve are greater in endurance-trained (ET) compared with sedentary control (SC) humans, we hypothesized that reductions of C and increases in Ea are greater in ET than SC individuals. The aim of this study was to investigate C, R, and Ea during exercise in ET and SC humans. C, R, Ea, and cardiac cycle length (T) were measured at rest and during exercise of 40, 60, and 80% maximal oxygen uptake using Doppler ultrasonography in 12 SC and 13 ET men. C decreased in an exercise intensity-dependent manner in both groups, but its reductions were greater in the ET than SC subjects. Consequently, although C at rest was greater in the ET than SC group, the intergroup difference in C disappeared during exercise. Exercise-related changes in R/T were relatively slight and R/T was lower in the ET than the SC group, both at rest and during exercise. Although Ea at rest was lower in the ET than SC group, there were no intergroup differences in Ea at 40, 60, or 80% maximal oxygen uptake. We conclude that the reductions of C from rest to exercise are more marked in ET than SC humans. This may be related to the exercise-associated disappearance of the difference in Ea between ET and SC humans.

Progressive resistance training without volume increases does not alter arterial stiffness and aortic wave reflection

Endurance exercise is efficacious in reducing arterial stiffness. However, the effect of resistance training (RT) on arterial stiffening is controversial. High-intensity, high-volume RT has been shown to increase arterial stiffness in young adults. We tested the hypothesis that an RT protocol consisting of progressively higher intensity without concurrent increases in training volume would not elicit increases in either central or peripheral arterial stiffness or alter aortic pressure wave reflection in young men and women. The RT group (n = 24; 21 +/- 1 years) performed two sets of 8-12 repetitions to volitional fatigue on seven exercise machines on 3 days/week for 12 weeks, whereas the control group (n = 18; 22 +/- 1 years) did not perform RT. Central and peripheral arterial pulse wave velocity (PWV), aortic pressure wave reflection (augmentation index; AIx), brachial flow-mediated dilation (FMD), and plasma levels of nitrate/nitrite (NOx) and norepinephrine (NE) were measured before and after RT. RT increased the one-repetition maximum for the chest press and the leg extension (P < 0.001). RT also increased lean body mass (P < 0.01) and reduced body fat (%; P < 0.01). However, RT did not affect carotid-radial, carotid-femoral, and femoral-distal PWV (8.4 +/- 0.2 vs. 8.0 +/- 0.2 m/sec; 6.5 +/- 0.1 vs. 6.3 +/- 0.2 m/sec; 9.5 +/- 0.3 vs. 9.5 +/- 0.3 m/sec, respectively) or AIx (2.5% +/- 2.3% vs. 4.8% +/- 1.8 %, respectively). Additionally, no changes were observed in brachial FMD, NOx, NE, or blood pressures. These results suggest that an RT protocol consisting of progressively higher intensity without concurrent increases in training volume does not increase central or peripheral arterial stiffness or alter aortic pressure wave characteristics in young subjects.

Arterial stiffness following repeated Valsalva maneuvers and resistance exercise in young men

The purpose of this study was to compare arterial stiffness after a bout of resistance exercise (RE) and an experimental condition consisting of repeated Valsalva maneuvers (VMs). Fourteen male participants randomly completed a lower-body, unilateral RE bout and a VM bout designed to alter blood pressure (BP) in a similar pulsatile fashion. Pulse-wave velocity (PWV, measured in metres per second (m.s-1)) was used to measure central and peripheral arterial stiffness and was assessed before and 20 min after each perturbation. Beat-to-beat blood pressure (BP) was assessed during bouts using finger plethysmography. Change in systolic BP, diastolic BP, mean arterial pressure, and pulse pressure were similar during both bouts. Central PWV increased after repeated VMs (7.1 +/- 0.3 m/s to 7.8 +/- 0.3 m/s), but not after RE (7.2 +/- 0.3 m/s to 7.2 +/- 0.3 m/s) (interaction, p = 0.032). There was no change in peripheral PWV after VM (8.9 +/- 0.3 m/s to 9.3 +/- 0.3 m/s) or RE (8.5 +/- 0.2 m/s to 8.4 +/- 0.2 m/s). Arterial stiffness increased after repeated VM. Even though presented with a similar BP load, arterial stiffness did not increase after acute RE. These findings suggest a role for VM in acutely altering arterial properties.

Arterial Stiffness and Wave Reflection following Exercise in Resistance-Trained Men

PURPOSE

Resistance training increases arterial stiffness and pressure wave reflection. We tested the hypothesis that potentially greater tonic arterial stiffness in resistance-trained (RT) men may alter the vascular response to an acute exercise stressor.

METHODS

Thirty participants (age 22 +/- 0.5 yr; 15 highly RT men and 15 sedentary non-RT men) underwent measures of central (carotid femoral) and peripheral (femoral dorsalis pedis) pulse wave velocity (PWV) and augmentation index (AIx; index of central pressure wave reflection derived from radial artery applanation tonometry and pulse wave analysis) before and 10, 20, and 30 min after maximal aerobic exercise.

RESULTS

RT men were significantly stronger (bench press 143 +/- 7 vs 85 +/- 2 kg, P < 0.05) and heavier (93 +/- 3 vs 82 +/- 3 kg, P < 0.05) than sedentary men. Groups did not differ in resting central/peripheral PWV or in AIx. AIx was not changed at 10 min after maximal aerobic exercise in both groups and was reduced similarly in both groups at 20 and 30 min after maximal aerobic exercise (P < 0.05). Peripheral PWV decreased similarly at all time points after maximal aerobic exercise in both groups and was not recovered by 30 min (P < 0.05). There was no change in central PWV after maximal aerobic exercise.

CONCLUSIONS

The arterial response to maximal aerobic exercise was similar in highly RT and non-RT men. There was no change in intensity of central pressure wave reflection 10 min after exercise, despite significant reductions in peripheral muscular artery stiffness. Arterial reactivity to an acute exercise stressor is not impaired in young, highly RT men.