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Do you have a linked to a version that doesn't require a login? I've seen articles that go back and forth in the heart issues
I copied the article and pasted it. See below.
A new study finds that exercise that is extreme in either volume or intensity may be associated with high levels of atherosclerosis in the coronary arteries.
The study, presented in August at a meeting of the European Society of Cardiology, studied 169 veteran competitive endurance athletes against a control group of 171 relatively sedentary subjects. Compared with the control group, the study found lower levels of coronary artery calcium in athletes who ran fewer than 35 miles a week or cycled fewer than 150 kilometers a week. But athletes who ran or cycled beyond that threshold were found to harbor higher levels of coronary artery calcium than did the control group.
The study, conducted by British physicians, is certain to intensify debate over one of the most controversial questions in modern medicine: Can people exercise too much? By all accounts, exercise lowers blood pressure, helps preserve coronary-artery integrity, lengthens lifespans and otherwise promotes physical and mental health. Exercise is medicine, say public health officials.
But unlike other medication, which is generally prescribed in scientifically determined doses, exercise typically receives a blanket more-is-better recommendation. “Most health benefits occur with at least 150 minutes (2 hours and 30 minutes) a week of moderate intensity physical activity, such as brisk walking,” says a U.S. exercise guideline. It adds: “Additional benefits occur with more physical activity.”
Now, a small but growing number of studies suggest that the benefits of exercise may diminish or even disappear beyond a point. Some evidence suggests that the longevity benefits of endurance exercise may disappear for some extreme athletes. Other evidence shows higher-than-expected coronary artery calcification in such athletes.
Any point of diminished returns would be far beyond the physical-activity habits of the vast majority of committed exercisers. Of the 169 serious endurance athletes examined in the British study, 41 men and 16 women ran more than 35 miles or cycled more than 150 kilometers a week, said Ahmed Merghani, a cardiology resident who led the study. The senior author of the study was British sports cardiologist Sanjay Sharma, medical director for the London marathon. The study is yet to be published.
Besides distance, the study found an association between coronary calcium levels and exercise intensity. Compared with the control group, the study found significantly lower levels of coronary calcium in the slowest men and women. In women, those levels rose as speed increased, though not to the levels of the relatively sedentary control group. The fastest men, however, had significantly higher levels of coronary calcium than did men in the control group.
Yet within the bad news for extreme endurance athletes the study also found good news. The type of plaque found within the heavy exercisers was dense as opposed to soft, and recent research has shown that dense plaque is less likely to rupture and cause a heart attack or stroke. “It is remarkable that the athletes in the Sharma study have less non-calcified plaque (the plaque that ruptures and causes heart attacks) than the non-athletes,” Benjamin D. Levine, a cardiology and exercise-science professor at University of Texas Southwestern Medical Center Dallas, said in an email.
Even so, plaque-free arteries are the ideal, and Dr. Merghani pointed out that even dense plaque can narrow arteries in a way that can pose danger during heavy exertion.
“It’s a very important study,” said Paul Thompson, a veteran marathoner who is chief of cardiology at Hartford Hospital in Connecticut. “It confirms prior reports of possible increased coronary calcium with increased amounts of exercise, implying more atherosclerosis. But it showed more calcified plaque, at least in male runners. Calcified plaque is probably more stable, less likely to rupture and thereby to cause heart attacks and sudden death.”
The British researchers recruited volunteers for the study via advertisements in athletic magazines. The 169 athletes chosen for the study were older than 40, had engaged in competitive endurance exercise for more than 10 years and were free of cardiovascular risk factors such as family history of heart disease. The control group was also older than 40 and free of cardiovascular risk factors, and its members exercised less than 150 minutes a week. The researchers used CT coronary angiograms to determine calcium scores and also identify the nature of the plaque found within those arteries.
Researchers speculate that potential causes of greater coronary calcium in extreme athletes could be inflammation, changes in the structure of the heart or an excess secretion of certain proteins or hormones. “It is true that exercise may increase parathyroid hormone levels, and thus MAY increase vascular calcification,” acknowledged Dr. Levine wrote in an email.
But Dr. Levine argues that substantial research supports a more-is-better mentality. Aging “athletes have youthful, compliant (flexible) hearts and large blood vessels that have a biological age more than 25 years ‘younger’ than their chronological age compared with their healthy but sedentary counterparts,” said Dr. Levine.
Other studies, along with the sudden deaths of famous runners such as Micah True, give other cardiologists pause. “Chronic excessive strenuous exercise can exact a toll on the durability of the cardiovascular system, on how well the pump holds up through the decades,” says James O’Keefe, a Kansas City cardiologist.
Most cardiologists are awaiting more research. “We know that there is some point where we reach diminishing returns” from exercise, says Clyde W. Yancy, a Northwestern University cardiologist. But “it remains very unclear” whether exercise at some point poses danger.
That's similar to what I've read but the other side to the calcium building is that the athletes when larger cardio bases and more vigorous activity tend to have larger hearts and arteries over time which in theory can offset the calcium building
That's similar to what I've read but the other side to the calcium building is that the athletes when larger cardio bases and more vigorous activity tend to have larger hearts and arteries over time which in theory can offset the calcium building
A lot of what is coming out about limiting glycolysis is based on the work of Victor Seluyanov PhD.
Here is what he writes about the heart:
"What is happening to the heart during training? It is important to understand that the heart is not a mechanical machine and it is relatively easy to damage it by training incorrectly. The main effect of training on the heart is the increase in minute volume, the amount of blood the heart is able to pump in a minute.
The heart gets larger, or develops hypertrophy with training. There are two types of cardiac hypertrophy: L-type, when the heart muscle stretches, its muscle fibers get longer and the volume of the heart increases; and D-type, when the thickness of the heart wall increases, therefore increasing the strength of contraction.
In order to increase the volume of the heart they use training at heart rates corresponding to the maximal stroke volume. Just as the reminder, stroke volume is the volume of blood expelled by the heart during one contraction. Usually stroke volume sharply increases at HR of 100/min, at 120 increases more and in some individuals still increases until HR of 150.
Prolonged training at maximal stroke volume is, figuratively speaking, “stretching exercise†for the heart. Muscles pump the blood, and the heart get stretched by the increased flow. As the consequence the heart dilates. It is possible to double its size, and 30-40% is almost a guarantee. That’s what is meant by coaches when they say “building the baseâ€; it is, in fact, stretching of the heart.
D-type hypertrophy is stimulated by the work at heart rates close to maximal – 180.min and higher. Again, a little reminder of physiology. The heart is the muscle and therefore needs the blood in order to contract. The blood is delivered to it mostly during diastole, or relaxation phase. When working at maximal heart rate, the heart does not fully relax, and the blood supply is impaired to some degree.
What follows is the accumulation of acidic substances leading to acidosis which, in turn, stimulates growth of the heart muscle. This is typical interval training, the rave of the fitness crowd in recent years. The problem starts when this kind of training is done too often. If the heart does not relax, its blood supply is impaired, the delivery of oxygen becomes inadequate and anaerobic glycolysis starts.
As the resulting lactic acid is produced and leads to the acidosis inside the cell. If it lasts long enough, some cellular structures die. And if it lasts some more, the whole myocardiocytes – heart muscle cells – can die. This is microinfarction. If the training of this intensity is repeated again and again, more cells die and are replaced with the connective tissue which, in turn, is poorly distensible and does not properly conduct electric impulses necessary for adequate cardiac contraction. Apparently this has been confirmed by autopsies of athletes who suddenly died during physical activity.
That is why it is important to first build the base – dilate the heart – and only then increase intensity. Working at heart rates close to maximal must be introduced gradually and done infrequently, especially at the early stages of training.
This also brings us to the topic of recovery and frequency of training. If your muscles are sore after a workout, you take a day or two off and allow them to recover, to heal. Why should the heart be different? Adaptation takes days and the heart muscle needs rest in order for these processes to take place.
This is not just a theory. Every year you hear of a few athletes dying as the result of sports activity, both professional and amateur. This year a 27 year old man died during City to Surf race in Sydney, the run only 14 km long. Did he have some undiagnosed cardiac condition? It is possible. But it is also possible that his heart was damaged by overzealous training."
I think I have been training incorrectly. I went for my EKG this year and was told my heart muscle wall was too thick. It was after this I reduced my training. What should I do? Throttle back in intensity?
I run fast (for me) for 3 miles once a week but now you really have me questioning what I'm doing. I'm hoping I haven't permanently damaged my heart from over training.
My daughter would like to join track next year. I was not allowed to be in any sports in high school, so I have no experience here. She has been running or using a stairclimber for exercise<>
Sounds like a good cross country prospect. When you think of all the unhealthy things she could be high on you should be thrilled!
"Adrenaline High!"
I think I have been training incorrectly. I went for my EKG this year and was told my heart muscle wall was too thick. It was after this I reduced my training. What should I do? Throttle back in intensity?
I run fast (for me) for 3 miles once a week but now you really have me questioning what I'm doing. I'm hoping I haven't permanently damaged my heart from over training.
pipsters, I am not a medical professional or an expert in this field, so I can only give you my opinion; some of which based on observences that could very well be considered conjecture. By all accounts, I encourage you to verify what I say, so you can learn for yourself and make your own decisions.
I was first introduced to the concepts I mentioned in the previous post by Pavel. Pavel has a forum where there are plenty of knowledgeable posters, including university professors with specialized knowledge on the subject from major universities, and other athletes and medical professionals that can help you formulate a strength and conditioning program with these concepts in mind.
I would recommend that you visit that forum and ask someone with more expertise and knowledge than I have. You'll also get some consensus and some alternative strategies because that forum is more specialized than this one, so it has a more narrow perspective.
I think the key components to being healthy and fit is creating a program that enhances your mobility, your stability, your flexibility, you strength and your endurance without creating harm.
A lot of people in particular neglect mobility and joint training. I recommend Flexible Steel or Superjoints for that. When it comes to stretching, I believe in a tension and relaxation based form, which can be learned about in Relax into a Stretch. Essentially, its premise is that you are not truly flexible unless you are strong at that range of motion.
Whatever you decide to do, good luck and I wish health upon you.
I think I have been training incorrectly. I went for my EKG this year and was told my heart muscle wall was too thick. It was after this I reduced my training. What should I do? Throttle back in intensity?
I run fast (for me) for 3 miles once a week but now you really have me questioning what I'm doing. I'm hoping I haven't permanently damaged my heart from over training.
I would suggest that you seek the advice of a good cardiologist, instead of anonymous posters on the internet.
From what I've read, it's important for every athlete to limit glycolysis if they can. In boxing for example, the best method to utilize is a general physical preparedness program throughout the year, and then having a short training camp where you peak just prior to performance.
Here is a good chart regarding performance that I got from Phil Maffetone's website.
As you can see from the chart, the athlete spends the majority of his/her time not exceeding their aerobic threshold, but just prior to competition, they peak after 2 months of implementing anaerobic training before plateauing and then regressing.
Maffetone tends to work specifically with endurance athletes, but a method that has been gaining more notoriety in other sports is using alactic & aerobic training to help build your VO2 max.
It basically involves doing a high intensity movement for about 15-30 seconds and then backing off to allow your heart rate to fall back into the aerobic zone before repeating the movement. This way, you minimize the amount of substrates created by utilizing your anaerobic fuel tanks, while improving your overall health and fitness.
Sorry, but none of this is relevant. If the child joins the track team, she will be running & training more than 1 hour a day. Most competitive athletes train more than an hour a day.
I think the problem here is that unless you are a doctor or a PhD in this specific field, you aren't really qualified to understand or interpret the results of this study, and certainly not to apply it to a generalization about all exercise routines, or even your own. I have read this study, and although my PhD is in a different field than this one, even I can see that you can't draw the kinds of conclusions you have drawn from it.
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