Effect of Exercise on Arterial Stiffness in Healthy Young, Middle-Aged and Older Women: A Systematic Review

Arterial stiffness, an age-dependent phenomenon, is improved with exercise, which in turn may prevent cardiovascular diseases in women. However, there is a lack of consolidated information on the impact of exercise on arterial stiffness among healthy women. The aim of this review was to (i) analyse the effect of exercise on arterial stiffness in healthy young, middle-aged, and older women, and (ii) recommend types, intensity, and frequency for each age group. Database searches on PubMed, ScienceDirect, Web of Science, and Scopus were conducted using PRISMA guidelines until September 2022. The keywords were: exercise, women/female, and arterial stiffness. The inclusion criteria were: healthy women, supervised exercise, and arterial stiffness measures. Study quality and bias were assessed using the PEDro scale. Fifty-one papers were classified into young (n = 15), middle-aged (n = 14), and older (n = 22) women. Improvements in arterial stiffness were observed among: young women (Pulse Wave Velocity, PWV: 4.9-6.6 m/s), following an 8-week high-intensity aerobic (3 days/week) or hypoxic high-intensity interval training; middle-aged women (PWV: 5.1-7.9 m/s), aerobic exercise with moderate intensity or stretching exercise at "moderate to heavy" (Borg Scale), 20-30 s per site, 10 s of rest interval for 30 min; and for older women (PWV: 7.9-15.6 m/s), resistance training at light intensity, aerobic exercise at any intensity, or a combination of the two exercises. This review shows that arterial stiffness increases with age in healthy women and has an inverse relationship with exercise intensity. Therefore, when prescribing exercise to improve arterial stiffness, age and arterial stiffness measures should be accounted for.

Reduced arterial stiffness in very fit boys and girls

Low cardiorespiratory fitness is associated with higher cardiovascular risk, whereas high levels of cardiorespiratory fitness protect the cardiovascular system. Carotid intima-media thickness and arterial distensibility are well-established parameters to identify subclinical cardiovascular disease. Therefore, this study investigated the influence of cardiorespiratory fitness and muscular strength on carotid intima-media thickness and arterial distensibility in 697 children and adolescents (376 girls), aged 7-17 years. Cardiorespiratory fitness and strength were measured with the test battery FITNESSGRAM; carotid intima-media thickness, arterial compliance, elastic modulus, stiffness index β, and pulse wave velocity β were assessed by B- and M-mode ultrasound at the common carotid artery. In bivariate correlation, cardiorespiratory fitness was significantly associated with all cardiovascular parameters and was an independent predictor in multivariate regression analysis. No significant associations were obtained for muscular strength. In a one-way variance analysis, very fit boys and girls (58 boys and 74 girls>80th percentile for cardiorespiratory fitness) had significantly decreased stiffness parameters (expressed in standard deviation scores) compared with low fit subjects (71 boys and 77 girls<20th percentile for cardiorespiratory fitness): elastic modulus -0.16±1.02 versus 0.19±1.17, p=0.009; stiffness index β -0.15±1.08 versus 0.16±1.1, p=0.03; and pulse wave velocity β -0.19±1.02 versus 0.19±1.14, p=0.005. Cardiorespiratory fitness was associated with healthier arteries in children and adolescents. Comparison of very fit with unfit subjects revealed better distensibility parameters in very fit boys and girls.

Exercise training improves aerobic capacity, muscle strength, and quality of life in renal transplant recipients

Renal transplant recipients (RTR) have reduced peak aerobic capacity, muscle strength, arterial function and an unfavorable cardiovascular disease risk (CVD) profile. This study compared the effects of 12 weeks of supervised endurance and strength training (EST, n = 16) versus usual care (UC, n = 15) on peak aerobic capicity, cardiovascular and skeletal muscle function, CVD risk profile, and quality of life (QOL) in RTR (55 ± 13 years). Peak aerobic capacity and exercise hemodynamics, arterial compliance, 24-h blood pressure, muscle strength, lean body mass, CVD risk score, and QOL were assessed before and after 12 weeks. The change in peak aerobic capacity (EST: 2.6 ± 3.1 vs. UC: -0.5 ± 2.5 mL/(kg·min)), cardiac output (EST: 1.7 ± 2.6 vs. UC: -0.01 ± 0.8 L/min), leg press (EST: 48.7 ± 34.1 vs. UC: -10.5 ± 37.7 kg) and leg extension strength (EST: 9.5 ± 10.3 vs. UC: 0.65 ± 5.5 kg) improved significantly after EST compared with UC. The overall change in QOL improved significantly after 12 weeks of EST compared with UC. No significant difference was found between groups for lean body mass, arterial compliance, 24-h blood pressure or CVD risk score. Supervised EST is an effective intervention to improve peak exercise aerobic capacity and cardiac output, muscle strength and QOL in clinically stable RTR.

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.

Muscular strength is inversely associated with aortic stiffness in young men

Muscular strength is associated with reduced mortality. Paradoxically, strength training may increase central artery stiffness, a predictor of cardiovascular morbidity and mortality. However, the relationship between muscular strength and central arterial stiffness has yet to be defined.

PURPOSE

The purpose of this study was to determine the relationship between muscular strength and central arterial stiffness in young men.

METHODS

Central and peripheral pulse wave velocity (PWV), augmentation index, muscular strength, and aerobic capacity (V O2peak) were measured in 79 young men (mean +/- SD, age = 23 +/- 4 yr). Height, weight, and brachial blood pressure were also recorded. Muscular strength was determined using a one-repetition maximum bench press and normalized to bodyweight. Spearman correlations were used to determine the relationships between relative strength, aerobic fitness, and hemodynamic/vascular measures.

RESULTS

There was a significant negative correlation between central PWV and strength (r = -0.222, P < 0.05). The relationship remained significant when controlling for aerobic fitness (r = -0.189, P < 0.05). Muscular strength was significantly higher (P < 0.05) in men with low central PWV (5.2 +/- 0.4 m.s) compared with men with high central PWV (6.6 +/- 0.4 m.s).

CONCLUSION

These results show that there is a significant inverse association between muscular strength and aortic stiffness independent of aerobic fitness.