As people age, the arteries that transport blood in and out of the heart are prone to hardening or stiffening, increasing the risk of heart disease. Although any form of exercise reduces the overall risk of death from heart problems, a new study finds different sizes of arteries are affected differently by varying amounts of exercise.
The new study discovered 2-3 days a week of 30 minutes exercise may be sufficient to minimize stiffening of middle sized arteries. However, exercising 4-5 days a week is required to keep the larger central arteries youthful.
The finding, which appears in The Journal of Physiology, is expected to help enhance exercise prescriptions designed to improve cardiovascular health.
For the study, researchers performed a cross-sectional examination of 102 people over 60 years old, with a consistently logged lifelong exercise history. Detailed measures of arterial stiffness were collected from all participants.
Participants were then categorized in one of four groups depending on their lifelong exercise history (an exercise session was defined as an activity that lasted at least 30 minutes):
- sedentary: less than 2 exercise sessions/week;
- casual exercisers: 2-3 exercise sessions per week;
- committed exercisers: 4-5 exercise sessions/week;
- masters athletes: 6-7 exercise sessions per week.
Upon analyzing the results, the research team found that a lifelong history of casual exercise (2-3 times a week) resulted in more youthful middle-sized arteries, which supply oxygenated blood to the head and neck.
However, people who exercised 4-5 times per week also had more youthful large central arteries, which provide blood to the chest and abdomen, in addition to healthier middle-sized ones.
The understanding that larger arteries appear to require more frequent exercise to remain youthful will aid the development of long-term exercise programs. The knowledge will also allow new research on whether or not aging of the heart can be reversed by exercise training over a long period of time.
Limitations to the study include the fact that individuals were allocated to groups based on past exercise frequency, as opposed to other components of exercise programs such as intensity, duration or mode, all of which could have large impacts on vascular adaptations.
Furthermore, additional, unmeasured factors such as dietary intake and social background could influence arterial compliance indirectly through reduced adherence, or by non-exercise related means.
Dr. Benjamin Levine, one of the authors of the study, said, “This work is really exciting because it enables us to develop exercise programs to keep the heart youthful and even turn back time on older hearts and blood vessels. Previous work by our group has shown that waiting until 70 is too late to reverse a heart’s aging, as it is difficult to change cardiovascular structure even with a year of training.
“Our current work is focusing on two years of training in middle aged men and women, with and without risk factors for heart diseases, to see if we can reverse the ageing of a heart and blood vessels by using the right amount of exercise at the right time.”