Study Overview
Objective. To investigate the association between habitually high levels of physical activity and the compliance of the large and small arteries in men and women throughout the life span.
Design. Cross-sectional study.
Setting and participants. 83 healthy men ( n = 44) and women ( n = 39) aged between 18 and 78 years were recruited to participate in the study. Potential participants were recruited via flyers designed to elicit responses from either very highly active (participate in regular, vigorous exercise more than 5 times per week) or less active/sedentary individuals (participate in light to moderate exercise less than 3 times per week or none at all). Both groups subjectively reported maintaining the specified activity level for at least the past 5 years. The highly active subjects performed regular vigorous swimming as their primary mode of exercise training as most were members of a varsity or masters swim team. All subjects were free of overt chronic diseases, nonsmokers, and none were taking vasoactive medications as assessed by a medical history questionnaire. All subjects provided written informed consent to participate. The study was reviewed and approved by the institutional review board at Indiana University.
Physical activity was self-assessed in all subject groups with a log detailing their activity over the previous 7 days. To ensure the older highly active population performed vigorous physical activity ≥ 5 days per week, the subjective activity log was verified by a 7-day previously validated, commercially available heart rate monitor and accelerometer (Actiheart, CamNtech, Cambridge, UK).
Main outcome measure . Compliance of the small and large arteries (inverse of stiffness) measured using a commercial pulse wave analyzer (Model CR-2000, Hypertension Diagnositics, Eagen, MN), which according to the manufacturer measures proximal capacitive compliance (C1, or estimate of large artery compliance) and distal oscillatory compliance (C2, or small artery compliance) [1].
Results. The study found a positive association between routine vigorous physical activity and arterial compliance. Specifically, the results suggest that vigorous physical activity is associated with greater compliance of the small and large arteries in both younger and older adults ( P < 0.05). In addition, both the highly active and less active younger groups as well as the highly active older group demonstrated greater large arterial compliance compared to the less active older group ( P < 0.008). No significant differences were found between men and women.
Conclusion. Researchers concluded that participation in habitual vigorous physical activity is associated with benefits to the compliance of the small and large arteries. Habitual vigorous physical activity over time may attenuate age-associated cardiovascular impairments.
Commentary
Arterial compliance declines with age, and increased arterial stiffness is associated with an increased risk of cardiovascular events [2]. Evidence suggests that physical activity may delay or prevent age-related increases in arterial stiffness [3]. Previous research regarding age-related arterial stiffness and exercise has focused primarily on the large arteries. For example, Tanaka found that regular aerobic-endurance exercise attenuates age-related reductions in central arterial compliance and restores levels in previously sedentary healthy middle-aged and older men [3]. More recently, a study by Duprez [4] found that small artery elasticity was superior to large artery elasticity with regard to predicting future CHD, stroke, and heart failure.
In this study, researchers cross-sectionally investigated the relationship of intense and continuous physical activity in young and older adults. The form of vigorous activity in this study was competitive swimming, as participants were recruited from a collegiate varsity and masters swim team. The study found a statistically strong association between routine vigorous physical activity and arterial compliance. These findings agree with several studies showing the benefits of vigorous exercise, but go beyond these by presenting findings on small artery compliance.
Methodologically, this study has some limitations. With the small sample, the study may not have been adequately powered. Further, physical activity assessment was by self-report in the main. Even though researchers had the participants keep a log, self-report measures may be inaccurate. Another limitation was the indirect method of measuring compliance, in which the radial waveform is calibrated to brachial blood pressure values. However, the researchers followed a valid model using the same BP level–based procedures reported in previous studies [1].
Applications for Clinical Practice
CVD is a major cause of disability and mortality in the United States. Health care professionals have a significant role to play in reducing cardiovascular risk factors in their patients, including encouraging aerobic exercise. The American Heart Association recommends at least 30 minutes of moderate-intensity aerobic activity at least 5 days per week or at least 25 minutes of vigorous aerobic activity at least 3 days per week, or a combination of moderate- and vigorous-intensity aerobic activity [4]. Patients can also be reminded that even modest levels of physical activity are associated with health benefits.
—Paloma Cesar de Sales, BS, RN, MS