Does a low heart rate always mean an enlarged heart size?

A thyroid problem could also cause a low resting heart rate. If your body temperature when you wake up is normally under 98 degree and you have the low resting heart rate, the next time you see your doctor and have blood work up, ask to have your TSH checked. -michael

I don't believe low heart rates means larger heart, though I'm no doctor. I've read that regular swimmers have lower heart rates, which is a good thing, a sign of healthier heart. After I took up swimming my heart rate lowered to around 50 from the 60's. But I'm not sure if 35 is OK, maybe it means you have a very healthy heart.

No, it does not.

A thyroid problem could also cause a low resting heart rate. If your body temperature when you wake up is normally under 98 degree and you have the low resting heart rate, the next time you see your doctor and have blood work up, ask to have your TSH checked. -michael My heart rate is obviously the result of swimming. If I take a break for a couple of months my heart rate goes up to 60 bpm. As soon as I pick up swimming again, my heart rate goes down again. I think if you train 4000-5000 yards a day and do a lot of cycling on the side it would be astonishing if you DIDN'T have a low heart rate. My question wasn't really if swimmers have a lower heart rate(which they usually do) but rather if they automatically have an enlarged heart when they have a low heart rate. No, it does not. Well, my resting heart rate of 35 bpm was 15 years ago and I'm still alive.;) My average resting heart rate these days is around 45 bmp. A lot of athletes have a resting heart rate of 35 or even lower though.

When I was in my 30's and a runner (doing 60-70 mi weekly) my resting heart rate was in the mid 40's. I quit running about 23 years ago and started swimming 9 years ago. My resting heart rate is now in the mid 50's. I'm not a doc either, but I think a lower heart rate is mostly due to the type and length of exercise we do. In some poeple it could be due to an enlarged heart but I don't think a lower resting heart rate of a conditioned athlete would be the result of this condition.

lower heart rate generally means better physicall fitness not large heart. however, it you want to be big hearted . . . seriously, I don't measure my heart rate, my satisfaction comes when the nurse can't find my resting pulse . . . because it's so faint and soft

I'm not a doctor nor any sort of medical professional, so I'm speaking as a everyday person from personal experience. When I'm in shape, I tend to have a low resting heart rate. 40 years ago, it tended to be under 50 beats per minute when checked first thing in the morning, before getting out of bed. As I have started to get back into shape since I started masters in October 2007, my resting heart rate has fallen from the low 60s to the mid 50s, suggesting that a single stroke of the heart muscle is able to pump more blood. My blood pressure, meanwhile, has tended to fall into the normal range as I swam more. A variety of medical imaging tests, conducted both before and after I started swimming masters, showed no enlargement of my heart muscle. My personal experience tells me the answer to this question is: no, the two should be unrelated.

A lot of athletes have a resting heart rate of 35 or even lower though. ___________________________________ I think if you train 4000-5000 yards a day and do a lot of cycling on the side it would be astonishing if you DIDN'T have a low heart rate I have emailed my doctor becuase I doubt that these statements are accurate. I'll let you know...

Lefty, for what it's worth, I once measured my heart rate, first thing upon awakening, before getting out of bed, at 38. It might have been lower, but I got so excited by the prospect of beating 40 that I could feel it speed up a bit towards the end of the minute. My father, who was a reasonably regular exerciser (tennis), had a lifelong low heart beat, and I am sure that some of this is genetically mediated. However, I do think that Lui's 35 is not all that difficult to believe, especially if he had been training a lot for a long period of time. By the way, if you look at the first link he sent, it was from (The American Journal of Epidemiology, 1999, Vol. 149, No. 9, pp. 853-862)--not that suspect, really. As far as Wikipedia goes, it seems to me I have come across academic studies that have found the info here to be as accurate as that found in the Encyclopedia Brittanica.

I have emailed my doctor becuase I doubt that these statements are accurate. I'll let you know... I know that I definitely used to have a resting heart rate of 35 bpm because I was checked by a cardiologist. Actually 35 was my lowest heart rate measured. Usually it was more around 40-43. Here is what I found about the topic with the help of Google: "Values range from 28 for elite athletes to as much as 100 for the very sedentary Known as a marker of fitness " findarticles.com/.../ "Elite athletes commonly have lower resting heart rates, some as low as the high 20s." www.thatsfit.com/.../ "Miguel Indurain, a Spanish cyclist and five time Tour de France winner, had a resting heart rate of 28 beats per minute, one of the lowest ever recorded in a healthy human." en.wikipedia.org/.../Heart_rate Additionally I also read on a triathlete board that many members had a resting heart rate around 30-35. Having said that, although I had a resting heart rate of 35 bpm, it doesn't automatically mean that I was fitter than another athlete who might have a resting heart rate of 45-50 bpm.