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Ventricular Hypertrophy vs Myocadial Wall Thickness


We all know that Healthy cardiac hypertrophy, which is the increase of the heart chamber is the normal response to healthy which results in an increase in the heart's muscle mass and pumping ability and reducing resting heart rate.

However I we know that by doing HIIT and other high intensity conditioning methods we increase fitness a lot more than doing standard aerobic exercise.

But I read this on wikipedia:

"In the case of chronic pressure overload (as through anaerobic exercise, which increases resistance to blood flow by compressing arteries), the chamber radius may not change; however, the wall thickness greatly increases as new sarcomeres are added in-parallel to existing sarcomeres. This is termed concentric hypertrophy.[11] This type of ventricle is capable of generating greater forces and higher pressures, while the increased wall thickness maintains normal wall stress. This type of ventricle becomes "stiff" (i.e., compliance is reduced), which can impair filling and lead to diastolic dysfunction."

What does this all mean


That means, if your blood pressure stays up long enough, your heart reacts via reinforcing the walls of the heart. Important factor here, that this growth isnt the best thing for your heart to happen, because bigger heart walls means stiffer heart walls, therefore walls that dont relax as well. if they dont relax aswell, they will take less blood inside (imagine an air balloon which is harder to pump up).

Aerobic training results in the heart's being able to pump a larger volume of blood through an increase in the size of the ventricles. Anaerobic training results in the thickening of the myocardial wall to push blood through arteries compressed by muscular contraction.[9] This type of physiologic hypertrophy is reversible and non-pathological, increasing the heart's ability to circulate blood.


So would that mean if one was to perform High intensity exercises through their life, the health of the heart may actually deteriorate??

Also what about HIIT for sprinting or cycling. Would this increase thickness of the heart walls as well??

Also can you increase the size of the ventricle and also increase the thickness of the walls??



answers here. wiki article meh...


A good conditioning program would lead to balanced increases in both. From what I have seen/read, strength coaches, who a few years ago were all jumping on the Tabata bandwagon, are seeing those effects in their athletes and adding LSD type work back in.


I have been diagnosed with an athletic heart , once at 42 and a second time at 50. I had to go through a work-up after having an abnormal EKG. Both work-ups consisted of treadmill and echo/dye. I was told by 2 cardiologists that I had an increased myocardial wall thickness with high to norm cardiac output and a resting HR of 40. I was told that it occured with adaptation to weight training for 30+ yrs and that there was no medication or lifestyle changes that they could recommend. If I wanted to have a normal EKG, I could stop training for 3-4 mths and my heart would decrease in size and stroke volume (normal). I have chosen to not stop training. There is a big difference between a heart adapting to training and a myocardial hypertrophy secondary to a disease process.


x2, and I'm 51.

I have athletic heart as well. Look, the heart is a muscle and like any other muscle it will respond to its environment. If you did heavy curls regularly for 6 months and saw zero change, then you'd mightily wonder about what's wrong with your arms or your training, right? same for the heart.

Those of us with AH have weirder vitals. low resting pulse rate (< 50 bmp), higher than normal upper bp number (mine is 135/55) which indicates that the heart is being an extremely powerful pump. There have been several high profile cases of sudden cardiac death, mostly during soccer matches, so any unusual cardiac behavior for athletes gets flagged. In those cases, there were neurological issue with the heart and AH head nothing to do with them (I have a study around here some place that discusses this at length). No study shows AH affects lifespan or cardiac health in a negative way.

The problem is if the lower bp number(= resting bp, between strokes) is high, which stretches the heart from being pear shaped to spherical. This will cause congestive heart failure which can only be fixed with a transplant.

Final issue issue to ponder is the myth that aerobic exercise makes your heart healthier. There was a study done some years back with older marathon runners and none of them had AH, but most all of them showed markers for cardiac damage after longer runs (which is absent in younger runners, btw). Since roughly 4% of the subjects died during races while the study was underway, the most reasonable conclusion is that running, especially longer distances is independent of cardiac health. It may be used as part of a cardiac training program, but is insufficient to ensure long-term cardiac health. With the deaths of several high-mileage running gurus (Jim Fixx, e.g.) it is quite clear that running does zero to offset damage to arteriosclerosis too.

(On the other hand, studies confirm that metabolic syndrome does not occur with nearly the same prevalence with people who are just physically strong, so weight training does have a provable positive effect on long-term health. The problem with it is that it is technical and a lot of hard work to do right. Aerobic exercises is appealing precisely because you can start immediately and do it badly without penalty, unlike a heavy squat.)




  1. No.
  2. Maybe
  3. Yes.

Simple enough. Do weight training to increase single stroke capacity. Do cardio (running, or whatever and HIIT can do it too) at a sustained clip that elevates your pulse to roughly 75% - 80% of your max (=220 - your age). Sustained aerobic activity will increase heart size.

The first way I got athletic heart was doing fartlek (cross country) training. This consisted of drawing a straight line on a map between two points in hilly/mountainous terrain and going from A to B, treating it like a massive obstacle course. (So jog, climb a cliff, shinny up a tree, crawl through under brush.. you get the idea) Awesome training. Heart was 25% above normal size after a year of that and my sports doctor figured I had roughly half again the heart/lung capacity of the average athete my age. Seriously brutal training though.

-- jj


Thanks bwhitewell and jj dude. Now I understand. This is actually the first time I have read this thread since my last post. This all helps. I haven't stopped doing HIIT or my other anaerobic exercises at all. I was just curious. Thanks


Good post.


I'm not sure that its reasonable to draw conclusions about the benefits of aerobic exercise from a study on marathon runners. There is a world of difference between them and someone who jogs for 1/2 hour a few times a week. Any activity taken to that kind of extreme is likely to be detremental to one's health.


I remember seeing a study that was done back in the 90s(or at least, that was when I saw the abstract). They studied a group of marathon runners(forget the size), and found the same thing in all of them - after every marathon, the runners all experienced muscle cell necrosis in their calves.