How artery stiffness changes with long-term strength versus aerobic exercise

Cardiovascular diseases are a leading cause of death globally, accounting for an estimated 38% of the 17 million premature deaths (under 70 years of age) (1). Understanding age-related cardiovascular changes is essential for the optimal prevention and management of cardiovascular disease (CVD) among older adults (2). Ageing is associated with significant changes to the heart and vascular structure and function, which makes older adults more susceptible to CVDs and resultant morbidity and mortality (3). Specifically relating to the vascular system, ageing results in significant structural remodelling and functional changes because of calcification, increased arterial wall thickness/diameter, loss of elasticity, increased collagen deposition, elastin fragmentation in the media layer and/or an impaired endothelial vasoreactivity (4). All these factors make the vessels stiffer and less elastic or resilient. This physical stiffening of the larger central arterial system forms the central model of vascular ageing (5).

Arterial stiffness increases progressively with age, this physio pathogenesis of vascular ageing is associated with the pathogenesis of a large spectrum of CVDs, such as systolic hypertension, coronary artery disease, cerebrovascular accidents, heart failure and atrial fibrillation, and non-cardiovascular outcomes, such as cerebral white matter lesions and several types of cognitive deficits (6), which are the leading causes of mortality worldwide. As such, increasing arterial stiffness has become a powerful and independent predictor of CVD or adverse cardiovascular outcomes in asymptomatic individuals (7).

Arterial stiffness is increasingly recognised as an urgent and modifiable CVD risk factor in the ageing population (8, 9). It is a key predictor of adverse cardiovascular events such as hypertension, stroke, and heart failure, conditions that disproportionately affect the older adult(s) (10). With the global ageing population on the rise, the prevalence of arterial stiffness continues to grow, significantly contributing to morbidity and mortality rates (11). Despite its critical impact on health outcomes, effective interventions to reduce arterial stiffness are still under-researched, making it a pressing public health concern (12). Addressing this issue through targeted interventions offers a promising non-pharmacological approach to mitigate cardiovascular risks and improve the quality of life in older adults. In this regard, since age-related changes in arterial stiffness are associated with differences in smoking habits, cholesterol levels, nutritional characteristics, blood glucose levels and regular exercise, the development of novel therapeutic strategies to impact these modifiable risk factors to reverse this process has begun to gain increasing attention (13). Over many decades of research in cardiovascular ageing, the role of regular exercise has become increasingly apparent in attenuating age-related decline in cardiovascular function (13). In this vein, recent studies have also demonstrated that the physiopathogenesis of vascular ageing can be slowed, reduced, or even reversed by regular exercise (14).

Whilst all mechanisms through which exercise affects arterial stiffness are not yet understood, it may do so through several physiological mechanisms. One primary mechanism is the improvement in endothelial function, where regular exercise enhances the release of nitric oxide (15), a vasodilator that helps maintain vessel flexibility (16). Regular exercise also affects the structural components of the arteries, such as elastin and collagen, which play key roles in arterial flexibility. Over time, regular physical activity can lead to favourable changes in these proteins, resulting in more elastic arteries (17). Additionally, exercise may reduce chronic inflammation and oxidative stress, and improve antioxidant capacity, all of which contribute to arterial stiffening (18, 19). Long-term regular exercise also improves atherosclerosis characteristics, such as improved serum lipid profiles, enhanced reverse cholesterol transport, and reduced atherosclerotic plaque (20). Whilst aerobic exercise has been shown to reduce sympathetic nervous system activity, leading to lower vascular resistance and improved arterial compliance (21), resistance training may contribute by increasing muscle strength, which can indirectly improve arterial stiffness through better blood pressure regulation (22). Combining these two exercise modalities may prove superior to any one modality in isolation. Crucially, a comparative analysis across sex and major racial/ethnic groups is needed to determine the generalizability of these training effects.

Further support for the role of exercise training in preventing and reducing high arterial stiffness is becoming evident from analysis indicating lower arterial stiffness in individuals with a higher aerobic capacity (14). In addition, whilst most studies have focused on the role of aerobic training on arterial stiffness (20, 23), some studies have investigated the differences between aerobic training and other exercise training types (24, 25), albeit in younger adults. When research is forthcoming on the long-term role of aerobic training on arterial stiffness in younger adults, it has been conflicting. This is especially true regarding the roles of resistance training (RT) alone or in combination with aerobic training on arterial stiffness. This is problematic because the effect on arterial stiffness may be varied in response to different exercise modalities due to underlying differences in the molecular mechanisms underlying the difference in the training effect (26). Therefore, the objective of this study was to systematically review the impact of RT or aerobic training alone versus concurrent aerobic plus resistance training on arterial stiffness responses in older adults.

In all, 1,543 articles were identified in the search, of which 1,527 were excluded, with 16 articles being included in this study. Specifically, 965 studies were excluded after reading abstracts and titles, a further 391 articles did not meet the inclusion criteria for outcome variables and 16 duplicates were removed. The remaining 171 full-text articles were read and assessed for eligibility. Then, 155 studies were excluded for the following reasons: the RT and/or aerobic training was combined with other activities (i.e., blood flow restriction); the experimental group consumed supplements or medications along with exercise without a defined control group; arterial stiffness was measured by another method than PWV; the participants’ mean age was less than 65 years; the experimental group consumed supplements or medications along with exercise; studies utilised acute interventions or interventions lasting less than 2 weeks. Finally, 16 studies were included in the review with a mean PEDro scale score of 4.8. The evidence available was rated for all reported outcomes as moderate-certainty evidence, which means that we have confidence in the estimates of effect. Three interventions involved RT alone (30–32), six aerobic training alone (33–37) and seven concurrent training (38–44) and their role on arterial stiffness in the older adult(s). No studies compared RT to aerobic training, RT to concurrent training or aerobic training to concurrent training.

Altogether, these studies evaluated 1,102 participants. Two studies enrolled only men (41, 43), six studies enrolled only women (35, 38–40, 42, 44) and eight enrolled both men and women (30–33, 36, 37, 45) Specifically, 100% of the RT studies enrolled men and women (30–33), 83% of aerobic studies enrolled men and women (33–37) with 17% enrolling only women (35). In turn, 71% of the concurrent studies enrolled only women (38–44), whilst 29% enrolled only men (41, 43).

This study provides one of the few direct comparisons of chronic resistance, aerobic, and concurrent training on arterial stiffness in older adults, and is the largest to date. The results indicate that RT alone does not significantly influence arterial stiffness, whilst aerobic training leads to modest improvements. In contrast, concurrent training consistently demonstrates the greatest benefits. These findings suggest that integrating aerobic and resistance training may be the most effective approach for enhancing vascular health in older adults (see Table 2).

To quantify the observed outcomes, the mean change in cfPWV for the three Resistance Training (RT) studies was negligible, ranging from −0.1 m/s to +0.1 m/s, confirming a lack of clinical effect. This finding of a neutral long-term effect from RT is consistent with major meta-analyses, such as those by Wainman (46) and Werner et al. (47), which found no significant change or only short-term increases in arterial stiffness following RT, particularly in older populations (61). In stark contrast, the single aerobic training (AER) study demonstrated a substantial PWV reduction of −1.0 m/s. This degree of benefit is supported by other systematic reviews, which generally report pooled PWV reductions from aerobic exercise in the range of −0.63 m/s to −1.29 m/s in comparable cohorts. This difference in magnitude underscores the superior effectiveness of aerobic training protocols over dynamic resistance training for improving arterial stiffness.

Across the studies reviewed, RT did not demonstrate a significant impact on arterial stiffness in older adults. This finding stands in contrast to cross-sectional studies involving younger populations, which suggest that RT, especially when conducted at high intensity, is associated with increased arterial stiffness (48, 49, 62). Importantly, the studies included here, which ranged in intensity from 70% 1-RM (30) to fatigue protocols (31, 32), did not demonstrate a deleterious effect on vascular function. These results align with previous findings showing that RT is not harmful to arterial compliance in older adults (50). However, the predominance of mixed-sex samples limits conclusions about potential sex-specific responses.

Whilst resistance training may not affect arterial stiffness, it remains a crucial part of exercise prescriptions for older adults due to its unique health benefits. Resistance training is essential for counteracting sarcopenia by promoting muscle growth, enhancing muscular power, and decreasing the risk of falls (51). Since arterial stiffening is associated with skeletal muscle mass decline (2), “hypertrophic” RT indirectly benefit vascular health. Future research should explore novel RT modalities (i.e., with varying volumes, loads, velocities, etc.) that enhance muscle outcomes whilst minimising health hazards to the vasculature (52). High-velocity concentric resistance training, for example, may have a smaller impact on arterial stiffness due to a reduced vasopressor response (52). Whilst careful selection of exercises could also limit stiffening associated with large muscle groups and upper-body eccentric movements (25).

Most studies reported a destiffening effect of aerobic training in older adults (33–37). However, findings were inconsistent in specific populations, such as hemodialysis patients (36) and older adult(s) hypertensives (37). One possible explanation is exercise modality: for instance, arm cycling, used by Westhoff et al. (38), engages a smaller muscle mass and provokes a greater vasopressor response compared to lower-body aerobic exercise (53). These methodological differences may explain variability in outcomes. Sex-specific remains underexplored, with only one study (36) addressing this question directly. Given known biological differences in vascular ageing, future studies should prioritise sex-stratified analyses.

Evidence from previous research strongly supports concurrent aerobic and resistance training as the most effective approach for reducing arterial stiffness in the older adult(s). Notably, Shiotsu et al. (44) found that performing RT before aerobic training produced a greater reduction in pulse wave velocity (PWV) than the reverse sequence (43). Similar benefits have also been observed in younger adults (25). These findings underscore the potential of concurrent training to not only mitigate any neutral or adverse effects of RT but also to combine the unique benefits of both modalities. Beyond vascular outcomes, concurrent training improves multiple cardiovascular risk factors, functional capacity, quality of life, and even psychological well-being (54), making it a particularly relevant strategy for both prevention and rehabilitation in ageing populations.

The differential effects of training modalities likely reflect distinct physiological mechanisms. Aerobic training reduces sympathetic nervous system activity, lowers vascular resistance, and enhances arterial compliance (21). resistance training may contribute by increasing muscle strength, which can indirectly improve arterial stiffness through better blood pressure regulation (22). Mechanistically, it increases phosphorylation of endothelial nitric oxide synthase (eNOS), improves nitric oxide bioavailability, and reduces inflammation (26, 55). By contrast, RT may indirectly support vascular health through blood pressure regulation and improvements in muscle mass and strength (22). However, high-intensity RT has been linked to increased endothelin-1, a potent vasoconstrictor that may offset eNOS activation (26). These findings highlight the need for mechanistic studies to clarify how RT, when combined with aerobic training, produces synergistic benefits for arterial stiffness. Rakobowchuk et al. (26) reported that the RT group’s PWV was unchanged (+1.04 m/s), whilst Guilherme Silva de Mendonça et al. (12) found that aortic PWV (PWVao) was unchanged (10.34 vs. 10.54 ± 2 m/s).

This review has both strengths and limitations. A notable strength is its focus on an underexplored population, as most previous studies on exercise and arterial stiffness have primarily involved younger adults (23, 56). By including older participants with diverse health conditions, the findings of this review are more clinically relevant. The outcomes were rated as moderate-certainty evidence, giving confidence in the estimates of effect. The observed non-significant PWV change must be interpreted considering our cohort’s composition, which was predominantly male and of Caucasian men origin.

However, several limitations need to be acknowledged, many of which are inherent to the nature of a systematic review. As a retrospective methodology, this review is bounded by the quality and design of the primary studies. Specifically, the wide variation (heterogeneity) in study designs, participant populations, exercise protocols, and arterial stiffness outcome measures (e.g., cfPWV vs. baPWV) made direct statistical comparisons challenging, necessitating a narrative approach to data synthesis. Moreover, any limitations or biases present in the original research could be carried forward and potentially amplified in this synthesis. For example, in some cases, details about the interventions were insufficiently described, hindering a complete evaluation of the training characteristics. Additionally, methods for assessing arterial stiffness varied (e.g., PWV versus augmentation index).

This review also highlights the implications of RT on vascular health and provides suggestions for future research. Whilst RT alone does not significantly impact arterial stiffness, combining it with aerobic training maximises vascular benefits and yields important improvements in musculoskeletal health and functional capacity. Future studies should focus on optimising concurrent training protocols by systematically adjusting key variables such as intensity, volume, and exercise order. Randomised controlled trials, particularly those including non-exercising control groups, are crucial for establishing the causal effects of these interventions. Additionally, future research should incorporate sex-specific analyses to determine whether vascular adaptations differ between older men and women. A better understanding of these factors will enable the development of more tailored and effective exercise prescriptions aimed at improving vascular health and overall well-being in older adults. Future studies should focus on optimising concurrent training protocols by systematically adjusting key variables such as intensity, volume, and exercise order. Furthermore, a critical area for future research involves conducting comparative studies between older and younger populations to clearly delineate age-related differences in vascular adaptations and further reinforce the clinical relevance of these findings in geriatric care. Finally, restricting the review to English-language studies may have introduced a language bias, a form of selection bias, by excluding potentially relevant research from non-English sources. Despite employing a rigorous, multi-database search strategy, the potential for residual publication bias, where studies with non-significant findings are less likely to be published, cannot be entirely eliminated.

RT is essential for maintaining strength and muscle mass in older adults. However, it does not significantly improve arterial stiffness. Importantly, RT does not negatively impact vascular function, even at higher intensities. In contrast, aerobic training consistently improves arterial stiffness. When combined with RT in a concurrent program, the benefits for vascular health are maximised. The findings also suggest that performing aerobic activity before RT and prioritising longer durations of aerobic exercise may further enhance vascular outcomes. Overall, these findings reveal that a well-planned concurrent exercise training program emerges as the most effective strategy for enhancing both cardiovascular and musculoskeletal health. This approach offers invaluable insights for health promotion and clinical rehabilitation, particularly for older adult(s) individuals facing an increased risk of cardiovascular disease. Additionally, future research should incorporate sex-specific analyses to determine whether vascular adaptations differ between older men and women. A better understanding of these factors will enable the development of more tailored and effective exercise prescriptions aimed at improving vascular health and overall well-being in older adults.