The Heart – Just what is it?
David Yon,
A human organ made of muscle sits in the middle of our chest, between the lungs. While it does not have the “thinking capacity” of the brain, it seems to be the core for defining our character. We speak of those who have a “compassionate heart,” a “heart of gold” or the “heart of a lion.” Others simply have “no heart” or are “cold hearted.” Our hearts are broken, stolen, lost, crushed and torn. We love with “all our heart.” Our language often suggests that it is the heart which is the source of our courage, moral and religious beliefs, and the ability to endure.
Perhaps it is because of the amazing job the healthy heart does. Nova Online reported in a PBS special that the average heart beats 72 times in a minute, about 100,000 times in a day, and approximately 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times. And it does all of this knowing that it cannot even take an hour off for lunch without disastrous consequences.
Of course the heart does this job to make sure the fuel the body (and especially the brain) needs to stay alive gets delivered on time. Again Nova calculated the average person has about 5.6 liters (6 quarts) of blood which circulates through the body three times every minute. “In one day, the blood travels a total of 19,000 km (12,000 miles)—that’s four times the distance across the US from coast to coast. It is also about 1 million barrels of blood during an average lifetime—that’s enough to fill more than 3 super tankers.”
For better and sometimes worse, we have the ability to alter these numbers, but not necessarily to control them. I remember often hearing from someone who doesn’t run that they thought doing so was not smart, stating the heart only has so many beats in it and since the heart rate goes way up while a person runs, running just brings the end that much faster. That of course (in addition to being fiction) ignores the impact of exercise on the heart. My heart just beat 47 times during the minute I spent counting the beats. It is probably not fair to compare that to 72 beats the average person experiences, but I have no doubt the number would be above 60 if I did not run on a regular basis. Fifteen beats per minute is more than enough to offset the increased rate I see during a run. On Sunday for example, my average heart rate for a 2 and a half hour run was above 115. But that is such a small portion of the day. Clearly, if you are counting heartbeats, the fit runner will, as a general rule, take a lot longer to hit the cap, if one existed, than someone who does not get aerobic exercise.
But that little muscle, not much bigger than your two fists, is far more complicated than that. No sooner had Jim Fix written the book, The Complete Book of Running, which probably got more people off the couch and into a pair of running shoes, than he died of a heart attack. (Actually, I think the best seller was published in 1977, while Fix died in 1984.) There is a long list of friends in our running community that have had major heart issues from blocked coronary arteries to electrical short circuits. Most unfortunately, we have lost a number of them. It seems only yesterday, I was lying in room waiting for a surgeon to open up a damaged artery (80% blocked) of mine with a stint.
Of course, no matter what, my heart always tells me to run. Perhaps that will not always be so. Despite the exceptions, the evidence is overwhelming that regular exercise, especially running, is good for you. But even if it wasn’t, that little workaholic muscle, the heart, always seems to be whispering that it isn’t “whole” without a good run.