Muscular Strength Training Is Associated With Low Arterial Compliance and High Pulse Pressure

Abstract

Abstract-Aerobic exercise training increases arterial compliance and reduces systolic blood pressure, but the effects of muscular strength training on arterial mechanical properties are unknown. We compared blood pressure, whole body arterial compliance, aortic impedance, aortic stiffness (measured by ␤-index and carotid pulse pressure divided by normalized systolic expansion Femoral-dorsalis pedis pulse wave velocity was also higher in the athletes, but carotid-femoral pulse wave velocity was not different. Furthermore, both carotid (56Ϯ3 versus 44Ϯ2 mm Hg; PϽ0.001) and brachial (60Ϯ3 versus 50Ϯ2 mm Hg; PϽ0.01) pulse pressures were higher in the athletes, but mean arterial pressure and resting heart rate did not differ between groups. These data indicate that both the proximal aorta and the leg arteries are stiffer in strength-trained individuals and contribute to a higher cardiac afterload. (Hypertension. 1999;33:1385-1391.) Key Words: mechanical properties, arterial Ⅲ stiffness Ⅲ compliance Ⅲ exercise A rterial compliance plays a role in determining both arterial systolic and diastolic pressure and therefore, in a clinical context, influences left ventricular size and function, coronary blood flow, and the risk of cerebrovascular accidents. [1][2][3] In the past, measures of arterial compliance in humans have been invasive, and therefore surrogate measures such as peripheral pulse pressure have been applied to investigate potential relationships with clinical outcomes. Pulse pressure correlates closely with serious cardiovascular outcomes such as myocardial infarction, 4 thus highlighting arterial compliance as a potential target for risk reduction therapy.Arterial compliance decreases with increasing age, 5-8 in atherosclerosis and coronary artery disease, 5,9 -12 and in hypertensive individuals. [13][14][15] Aerobic exercise has welldocumented efficacy for cardiovascular risk reduction, and it appears that at least part of its benefit derives from modification of arterial properties. In cross-sectional studies, aerobically trained athletes have a higher arterial compliance than sedentary individuals. 6,16,17 Furthermore, arterial compliance is elevated independently of blood pressure reduction in previously sedentary males after a 4-week program of moderate-intensity aerobic exercise training. 18 These data suggest that aerobic exercise structurally modifies the large arteries, a postulate supported by studies of ex vivo aortic properties in rats, after 16 weeks of spontaneous running. 19,20 While aerobic exercise is widely recommended as a preventative and therapeutic strategy, resistance-style training is becoming more popular, although it is less well studied with respect to its effects on blood pressure, and no previous study has examined arterial mechanical properties in this context. High-level resistance training is associated with abrupt and large pressor responses 21 and in the long term leads to a concentric ventricular hypertrophy. [22][23][24][25] We hypothesize that arterial mechanical modifica...

Effect of 4 weeks of aerobic or resistance exercise training on arterial stiffness, blood flow and blood pressure in pre- and stage-1 hypertensives

“…Similar findings have been seen with increases in stiffness in the central arteries following resistance training in both acute and training studies. 12,41 Miyachi et al 11 reported a 19% decrease in central arterial compliance following 4 months of strength training in 14 young men compared to sedentary controls, but with no changes in peripheral compliance. It should be noted that not all studies have shown an increase in central arterial stiffness following resistance training, 42 but these studies included different populations and employed a different exercise prescription.…”

“…Confounding the recommendation employing RE as an exercise regimen, recent evidence indicates that RE may cause increased arterial stiffness in young, healthy normotensive individuals. 11,12 However, these findings are controversial, as not all studies show an increase in arterial stiffness with resistance training. 13,14 Increases in arterial stiffness, which are associated with increased mortality and morbidity, can lead to decreases in blood flow because of increased peripheral resistance.…”

“…15 As arterial stiffness is related to increased pulse pressure and myocardial load, RE may potentially lead to myocardial hypertrophy. 12 These changes may be further exacerbated by hypertension. 16,17 Studies investigating flow-mediated vasodilation (FMD) have shown that moderate-intensity AE significantly increased FMD in hypertensive and normotensive subjects, likely mediated through augmented endothelial function.…”

Changes of central haemodynamic parameters during mental stress and acute bouts of static and dynamic exercise

“…37 Chronic dynamic training is associated with lower central AS in young men 38 and coronary patients, 39 whereas chronic resistance exercise results in stiffer large arteries in both young men 40 and athletes. 41 In the present study we assessed the effects on indices of stiffness (T i , AI) of the large arteries during the acute bouts of exercise (static and dynamic) and during mental stress. Since we did not measure carotid to femoral PWV, our data refer to estimated AS and peripheral wave reflection (by assessing T i and AI as surrogate parameters) rather than directly measured central stiffness per se.…”

“…With respect to exercise, there is evidence that chronic dynamic training has a beneficial effect on AS, 7 whereas chronic resistance exercise may have an unfavourable influence on central haemodynamics. 8,9 Nevertheless, there is little and inconsistent data about the effects of acute bouts of exercise on AS. Acute aerobic exercise was found to induce either an increase 10 or a decrease 11,12 in central AS, whereas studies on acute bouts of resistance exercise showed either an increase 13 or no effect 14 on central AS.…”