If you want your heart to flutter, there are probably other things you would do than elite endurance sports. Surprisingly, however…
Generally exercise is good for your heart, except in some cases of acute heart trouble. But things are not quite as simple as they sound, Scandinavian scientists have found out.
Studies of runners over 40 in the Norwegian â€œBirkebeinerâ€ race and the Swedish â€œVasaloppâ€ race show that the top runners were far more likely to experience disturbances in their heart rhythm than the less â€œeliteâ€ participants. Both those who ran the fastest and those who ran most frequently had dramatically more cases of arrhythmia. In the Vasalopp, those who had participated at least 7 times had 29% more risk compared to those who had participated only once. And those who had run at less than 1.6 times the winning time had 37% more than those who ran at more than 2.4 times the winning time.
The most common disturbance is extra beats, which are considered harmless but tend to be disturbing. However, these people are also more at risk for oscillations, which can be life threatening. This risk is far lower, but even those who survive will usually have to step down from elite competition.
There is as of yet no official explanation for the findings, but the hypothesis that has been mentioned is a larger heart in top-trained individuals.
Regular readers will guess why I noticed these articles: Both this year and in 2005, I developed heart rhythm disturbances after a few months of regular exercise. Not exactly a great incentive to continue exercising, although the doctors and available literature assure me it is not life threatening at the current level.
There is a big difference however between me and the elite runners: I donâ€™t run at all, I just walk (although in some cases I walk up long hills, which is an equivalent load to running on flat terrain, but uses the muscles differently.) There is nothing elite about my physical exertions at all. There are two other similarities, though.
Most notably, I have a remarkably low heart rate. Usually my resting pulse is in the interval 55-60, which is on the low end of normal. But late this summer it fell to 50, which is only normal for those who are active in endurance sports: Runners, bikers, swimmers etc on at least local competition level.
In addition, I am not visibly fat. It is kind of weird to even have to mention this, but these days it is normal to be fat if you are not an athlete.
I am pretty sure it is the first of these that is the key here. I believe the extra beats arise as a result of the slow heart rate. In the pause between beats, the heart is probably in some way more susceptible to false clues to start another beat. For most people, that pause is simply too short to trigger extra beats often (without the help of caffeine or romance, at least). As the beat gets slower, the opportunity for false starts increases. That is how I imagine it. I don’t have any medical education whatsoever, but it seems logical and it fits the fact.
So basically I consider myself a control group. If it was just the exercise that caused the change, then it would not affect me, since I exercise much less. But if the exercise causes this by lowering the heart rate below a certain threshold, then it would work for both of us.
Of course, there are (as implied from the start) many other things that can cause the heart rhythm to get unstable. But those are not things that change with the amount of exercise. If anything, exercising more means less time to drink coffee, and surprisingly also less nervousness. Whether it also causes less romance, I won’t have an opinion on. ^_^
Note that for most people these days, their pulse is on the high side rather than the low. This has its own problems. If your pulse is above 80, you should have a talk with your doctor about finding ways to exercise in a gradual way so as to build up your heart, and get the heart rate down. Obviously most people in the western world face very different health challenges from what I and the top athletes do! How did I end up in the wrong bin anyway?