Niha Zubair, Arivale Clinical Research Scientist, PhD
[Arivale Hot Topics address health stories currently in the news. The Arivale Clinical Team’s commentary on these news articles is not a review of the scientific evidence, nor an endorsement of a specific study, and is not meant as official medical opinion.]
It’s well-established that exercise is important for reducing cardiovascular risk and mortality, and the World Health Organization has long recommended 150 minutes of moderate-intensity aerobic exercise per week as the minimal standard for good health.
But, there has been some debate regarding the exact amount of exercise necessary to keep a healthy heart. A study published May 20 in the Journal of Physiology and covered by Time may have the answer.
As we get older, our arteries begin to stiffen – a sign of vascular aging – which negatively impacts our heart health. Sedentary lifestyles are associated with a greater degree of stiffness, which in turn increases the risk of hypertension and cardiovascular disease.
The aim of the new study was to evaluate the effect of exercise on arterial stiffness over the course of time and determine the amount of exercise necessary to improve arterial health.
This longitudinal study followed 102 primarily white men and women over the age of 60 who had logged their exercise over the course of 25 or so years. The study excluded participants with obesity, high blood pressure, diabetes, and cardiovascular disease, among other factors.
The study participants were divided into four groups: sedentary (two or fewer 30-minute sessions of moderate exercise per week), casual exercisers (two to three sessions per week), committed exercisers (four to five sessions per week), and masters athletes (six to seven sessions per week). Participants completed an exercise stress test and testing of vascular health (aortic arterial pressure and doppler ultrasound).
The major findings from the study demonstrated that four to five 30-minute sessions of moderate exercise per week over a lifetime was associated with a reduction in large – or central – arterial stiffness in seniors. (There are various sizes of arteries in the body. Medium-sized arteries feed the head and neck, larger-diameter vessels feed the chest and abdomen, and smaller arteries feed the peripheral tissues.)
Lifelong casual exercise – two to three sessions per week – was associated with lower medium-sized artery – or carotid artery – stiffness and central blood pressures in seniors but did not affect central arterial stiffness. Stiffness in smaller arteries was unaffected by lifelong exercise training, irrespective of frequency.
These current findings suggest the best effect of aerobic exercise for cardiovascular health was seen at 30 minutes of moderate aerobic exercise four to five times per week throughout a lifetime.
As with any study, there are limitations.
First, the study did not invasively examine the structural and functional adaptations of blood vessels associated with lifelong exercise training frequency via biopsy – only through non-invasive techniques.
Second, some factors – dietary intake, non-exercise physical activity levels, social background, educational levels, and economic status – weren’t assessed in the study and may influence arterial compliance.
Third, the study did not include type, intensity, and duration of exercise. The questionnaire only looked at 30 or more minutes of moderate exercise; it didn’t list the type of exercise.
Fourth, gender differences were not considered.
Lastly, subjects were non-obese, weren’t hypertensive, and were carefully screened for cardiovascular disease. Therefore, it’s unclear whether the results are applicable to a broader population of patients with greater amounts of risk factors.
Regardless, the study supports the idea that exercise is important for many aspects of health, including heart health, from an early age and should ideally be spread out over the course of a week – as opposed to lengthy but infrequent sessions.