Low heart rate - uses and origin?

July 11, 2006 12:46 AM

A recent medical exam showed that I have bradycardia - an abnormally low resting heart rate (32-34bpm). Does this mean I'm physiologically suited to endurance sports?

My ECG reading at a recent medical exam was 32 and 34bpm. The doctor said he'd never seen anything like it, and that rates in the 30s were usually only seen in olympic-level endurance athletes. Three questions:

1) Should I quit my job and start training for the Tour de France? or, more seriously, should I start competing in running etc? I've always just trained alone rather than raced. I don't fancy a career as a sniper, in case anyone was about to suggest it..

2) Is this condition likely to be the result of genetics or sport training or both? (none of the rest of my family have similar results, though on my mother's side all the women live to late 90s - could be good 'heart genes'..). For the past 4-5 years I've exercised for at least 1 to 1-and-a-half hours every day, either running, weights or cycling, plus cycle commutes. I push myself pretty hard. But some people (http://ask.metafilter.com/mefi/37695) seem to be able to slow their heartrate deliberately - maybe I'm doing this?

3) Are there likely to be links between this and my inability to stop myself from falling asleep within minutes in any sort of boring meeting or lecture; or my general lack of ability at sprinting and other 'fast-twitch' sporty stuff; or my poor circulation (my hands become numb and extremely weak in cold weather)?

posted by spiff101 to health & fitness (16 comments total)

There's something wrong with this story. Would you consider adding an email address to your profile?
posted by ikkyu2 at 1:21 AM on July 11, 2006

ikkyu2, I just added my address.
posted by spiff101 at 3:10 AM on July 11, 2006

In case ikkyu2 doesn't get back to you...

Genetic freak or not, the level of athletically induced bradycardia you are describing is not something you would just stumble into. Certainly not with the exercise level you are describing, because that is about my level of exercise and my resting heart rate is in the low 70s.

Just to put it in perspective for you, Lance Armstrong has the resting heart rate you are describing. He may have been born with a slightly lower heart rate than the average person, but the reason his heart rate is so low now is because his body has adapted to his training. The lowered heart rate was induced by the training. Without training at the level he does, his resting heart rate wouldn't be that different from the average person's.

If your doctor didn't see this as cause for concern, then you need to seek out a different doctor.
posted by 517 at 5:43 AM on July 11, 2006

Are there likely to be links between this and my inability to stop myself from falling asleep within minutes in any sort of boring meeting or lecture; or my general lack of ability at sprinting and other 'fast-twitch' sporty stuff; or my poor circulation (my hands become numb and extremely weak in cold weather)?

I suspect a better doctor would say: yes, yes, and yes. See if I'm right. I also suspect that he would tell you not to start any form of physical training given this picture.

This low rate (in a non-athlete) means that your heart is not getting blood to your various organs in an efficient way.
posted by megatherium at 5:51 AM on July 11, 2006

Good gosh, how are you still alive?!!!
posted by IndigoRain at 5:59 AM on July 11, 2006

It doesn't seem that unusual to me. I'm not a doctor, but when I'm training at anything like a decent amount for running (not even that much, ~40/mpw) my resting heartrate drops into the mid-30s. Your doctor is wrong about low resting heartrates of that nature being confined to elite athletes.

On the other hand, it sounds like your HR was that low even though you were not resting which makes it more remarkable and may be what is causing the confusion.
posted by OmieWise at 6:01 AM on July 11, 2006

Would you mind sharing the discussion with ikkyu2? I am in a similar boat (my resting pulse is not quite as low as yours but is <40 and will set off alarms on pulse and bp-measuring machines; I have poor circulation, eg, Raynaud's in my fingers and sometimes toes; I fall asleep at the drop of a hat; and for years I've been excercising ~1 hour/day 5x a week) and I'd love to hear/read the discussion.
posted by tentacle at 6:01 AM on July 11, 2006

Wow! I was concerned when I woke up one morning and my pulse was below 50 (it's normally about 58/59). I exercise so I eventually realized that this was nothing to worry about (especially after talking to others.) IANAD but common sense would make me think that you really need to go to a cardiologist.
posted by ob at 7:40 AM on July 11, 2006

Remember, however, that Lance has the highest VO2 max ever recorded. In other words, he's a freak of nature.

I agree with megatherium. Usually the heart rate is low in endurance atheletes because it is strong and a single beat pushes the blood farther throuought the circulatory system. That means they use less energy getting blood to the muscles and cool off more efficiently as well.

Thus you need to find out if the reason your heart beats slowly is because of a bad timer or because it is so incredibly strong that it need not beat as fast as others to move blood around. I'd suspect that it is the former.
posted by Ironmouth at 8:33 AM on July 11, 2006

Get the test repeated at a different place to make sure.
posted by FergieBelle at 8:41 AM on July 11, 2006

Note also that the wikipedia article on the subject seems to indicate that its a pacing problem with the heart's mechanism, not strength. Remember Lance got that way through 6 hours of exercise a day, not 1 1/2. I would be checking with your doctor about your exercise right away.
posted by Ironmouth at 8:48 AM on July 11, 2006

Wikipedia may or may not be correct on this subject, but I wouldn't suggest anyone depend on it for accurate medical (or anything) information.
/derail
posted by small_ruminant at 1:06 PM on July 11, 2006

Damn, I just wrote a long post and it disappeared. I have the same symptoms, and it sounds like our physical activity levels are very similar. I've done research in the past and drew the conclusion that the heart rate was unusual, but not a cause for concern, but I'll be interested to hear what you find out if you don't mind keeping me in the loop.

I have another genetic condition that on the surface seems unrelated, but I wonder if there's some connection. I have twice the normal good cholesterol of the average person and half the normal bad cholesterol. My doctor says women with this condition are unusually long-lived. You don't happen to know what your cholesterol levels are, do you?
posted by Evangeline at 2:30 PM on July 11, 2006

@Evangeline: I didn't do your particular research, but while I'd say that about 60bpm, I don't think I'd say it about 40.

Just sayin'
posted by baylink at 7:22 PM on July 11, 2006

thanks for the responses everyone.

tentacle, that's very interesting that you share some of those other characteristics. Btw ikkyu2 just asked if I am sure about my rate, if I've tested it myself: well, apart form the ECG, the doc also took my pulse rate at the wrist later, after telling me about the first results, and it was nearer 40, perhaps because I was kind of surprised and excited about the news.

I just took my pulse rate now and it was 45 - again, maybe because it's about 30 degrees C here and I'm sweating like anything, and I'm in the middle of working on a lot of office stuff. So there seems to be quite a lot of variation, depending on time of day, state of mind etc? What should I regard as my 'real' resting rate?

Evangeline, I have a sheet from the exam with all kinds of medical acronyms on them: if I lay some of them out can you interpret them?
Glucose GODHX-M: 5.2 mmol/; Cholesterol CHOD/PAP 3.47;
Triglycerides GOD-PAP 0.583; HDL Enz Col Test 1.02;
LDL Direct LDL 1.5; Creatinine JAFFE 86.47 umol/l;
Cholesterol/HDL REL 3.4; ASAT IFCC 50 U/L.

There are some others and numbers marked 'Interval' as well, but I'll shut up now.
posted by spiff101 at 6:55 AM on July 12, 2006

I've always thought that a 'real' resting heart rate should be taken when you first wake up in the morning (given that you haven't woken up in a start!).
posted by ob at 8:40 AM on July 18, 2006