main article image
(Lars Neumann/iStock)

Do We Really Only Get a Certain Number of Heartbeats in a Lifetime? Here's What Science Says

Make them count.

MIKE MCRAE
14 APR 2018
 

"I believe that every human has a finite number of heartbeats," the famous quote goes. "I don't intend to waste any of mine running around doing exercises."

Contrary to what you might have heard, Neil Armstrong never said this. What's more, he disagreed with it. But as much as it's a misattribution, was Armstrong right to argue?

 

The simplest answer is 'yes'. There is no strict tally for your ticker, keeping track of your pulse until you've used up your allocation of beats. So get out and exercise (after you've finished reading this article, of course).

But there is a more complex answer, one that suggests there is at least some kind of relationship between our heart rate and overall life expectancy.

In 2013, a team of Danish researchers published in the journal BMJ Heart 16 years of work on just under 5,200 men.

Of the roughly 2,800 individuals who provided a decent bank of medical data, just over a third had passed away by the end of the trial from various causes.

Matching the sample's resting heart rates with the rate of mortality led the researchers to believe that higher pulses correlated with a greater chance of dying.

Those with between 71 to 80 beats per minute had a 51 percent greater chance of kicking the bucket during that period than those with a resting rate of under 50 beats. At 81 to 90 beats per minute, that risk was double. Over 90, and it tripled.

 

In case you're thinking this was all about fitness or risk of cardiovascular disease, they took those factors into account. Even those who were in otherwise good physical condition seemed to be at risk, so once again, don't use this an excuse to do avoid going for a run.

This sly nod to a relationship between life expectancy and heart rate extends past individual humans – other animals appear to obey a similar ballpark rule.

Check out this website to get some idea of what your pulse is like when compared with, say, a giraffe's.

As we've seen, humans have on average a heart rate of around 60 to 70 beats per minute, give or take. We live roughly 70 or so years, giving us just over 2 billion beats all up.

Chickens have a faster heart rate of about 275 beats per minute, and live only 15 years. On balance, they also have about 2 billion beats.

We seem kind of lucky. A whale has around 20 beats per minute, and lives only slightly longer than us. It gets just under a billion heart beats.

 

An elephant? Try 30 beats per minute for around 70 years, giving roughly a billion as well.

The poor little skittish hamster has a rapid-fire pulse of 450 beats every minute, squeezed into three short years. That also adds up to a little under a billion.

This rule isn't a hard and fast one, given differences of a few million here and there.

But if we look at it in rough orders of magnitude, there does seem to be a heart-wrenching link between living fast and dying young for all creatures great and small.

 

More From ScienceAlert

A pet raccoon found itself on a 2am weed trip to a fire station
11 hours ago