How much exercise does it take to protect your heart and cardiovascular system? This has been the subject of lots of studies and conjecture. Some say that you need to exercise 6 days a week, others 5, some older studies suggested three times a week. This new study that I’ll review this morning came up with an unexpected answer. If you haven’t been a big exerciser, is it ever too late to start?
Exercise and the Heart
It’s a well-known fact that exercise and a healthy heart go hand in hand. For optimal heart health, the American Heart Association recommends, at a minimum, aerobic activity (moderate intensity) for 30 minutes five days per week or a specific combination of vigorous aerobic activity and muscle strengthening. Lack of exercise, or a sedentary lifestyle, is well-associated not only with stiffening of the left ventricle of the heart (the part of the heart that pumps oxygenated blood to the rest of the body) but also arterial stiffness, creating stress and extra pressure on the heart and throughout the circulatory system.
All things being equal, it’s understandable that someone who has been involved in lifelong exercise is going to have a healthier heart than someone involved in a lifelong sedentary lifestyle. But how much is just enough to keep everything in mostly working order?
Casual Exercise Two or Three Days a Week Has Heart Benefits
A new study consisted of 102 subjects aged 60 and older placed into four separate groups: sedentary (exercise less than twice a week), casual (exercise two or three times a week), committed (exercise four or five times a week), and master (exercise six or seven times a week). Researchers measured both arterial and ventricular stiffness, the two areas most affected by lack of exercise.
The results? As would be expected, those who were lifelong committed and master exercisers (four+ sessions per week) had less stiffness in and, therefore, “more youthful” arteries, while the sedentary group had the opposite. Interestingly, the casual exercise group (only two to three times per week) was found to have less stiffness in the critical carotid artery, and there was also a decrease in ventricular pressure and pressure in the peripheral arteries. Healthier arteries mean less stress on the heart, so all but the sedentary group (those who exercised less than twice per week) were found to have heart benefits with exercise.
While the good news is that researchers in this study suggest it doesn’t take as much exercise as previously thought to keep the heart healthy, this study did only investigate exercise in those who have exercised regularly for 25 years or more. So what does that mean for those who become fitness enthusiasts or begin regular exercise later in life? The answer to that question wasn’t within the scope of this study; however, prior studies suggest there are endless benefits to be realized from regular exercise regardless of when you start.
More Heart Benefits to Exercise
While the study above didn’t address how starting an exercise plan in middle age or beyond effects heart health, another recent study did. It found that even in a middle-aged person who’s left heart ventricle has stiffened due to a chronically sedentary (or unfit) lifestyle, exercise can reverse some of the damage and lower heart failure risk. Over a period of just two years, regular aerobic exercise (30 minutes of exercise four or five times a week) decreased the stiffness in the ventricle by 25% and increased oxygenated blood entering left ventricle (from the lungs) by 18% (click on the link above to learn more details about blood circulation and the heart).
Immune System Benefits
Exercise has also been shown to keep your immune system healthy as you age. A healthy immune system can properly fight off bacteria, viruses, and so on, which in turn keeps the whole body healthier. Again, lifelong exercisers, understandably, have a leg-up here; however, even starting in middle age is likely to give your immune system a nice boost.
The gut microbiota is the community of bacteria in the gut. When the bad bacteria are abundant and in charge, the gut microbiota is unhealthy and in disrepair. When the good bacteria are abundant are in charge, the gut microbiota flourishes and thrives. A study last year found that exercise helps those good gut bacteria thrive. And, interestingly, when exercise stopped for a period of time, the gut benefits were no longer realized.
As we age, our muscles lose stem cells, those “repairman” cells that naturally repair and regenerate tissues. The older we get, the more muscle mass we lose, and this is why you see many older people who seem to get smaller and smaller—their muscles really are shrinking and wasting away. Studies have found that regular exercise may help retain those stem cells and maintain muscle mass as we age.
There are many, many more benefits to exercise, such as losing weight, increasing lifespan, decreasing mortality, lowering genetic age, boosting brain health, and so on, and exercise benefits can be achieved at any age and by anyone who chooses to leave a sedentary lifestyle behind them.
The upshot? Get out there and exercise! While I’d prefer to aim for 5-6 days and if you get sidetracked, you’re still well over the lower limits, even if you can only do three days a week, it’s likely protective. In addition, if you know someone who has never exercised and says they’re too old, show them this new research. You’re never too out of shape, with the help of the advice of your physician, to get back at it!