The idea that there is a limit to the number of heartbeats in a lifetime is seductive and based on an ancient myth, but science shows that the story is not quite so
Imagine if your smart watch it didn’t just tell you how many steps you took or how many calories you burned, but how many heartbeats you “spent” per day. According to a recent study, this number could one day become another indicator of health: a “heart rate budget” that could, in theory, tell you whether you’re spending too much on your most vital resource.
The idea of a lifetime heart rate limit has been around for decades. It’s based on an old myth that the heart has a fixed number of beats it can produce, generally estimated at around 2.5 billion, so every extra beat you use brings you closer to exhausting that limit. Fortunately, it is now widely recognized that this is not true.
Exercise does not shorten your life by making your heart beat faster. In fact, people who exercise tend to have a lower resting heart rate and live longer. But new research, published in the scientific journal JACC: Advancesuses this same metaphor in a modern, data-driven way.
The scientists behind the study analyzed fitness app data from elite athletes, comparing their resting heart rate to their total daily beats. They estimated that resistance-trained athletes “saved” about 11,500 heartbeats per day compared to untrained adults, thanks to lower rest rates.
But this economy doesn’t last. A single stage of the Tour de France can cost cyclists around 35,000 extra beats, researchers estimate, reflecting how hard the heart works during a competition.
This “push and pull,” saving heartbeats at rest and expending them during exertion, is what researchers call heart rate consumption. The concept is simple: Your daily beat totals reflect how your heart responds to everything you do, from sleep to stress to sports. Fitness trackers already measure heart rate continuously, so it wouldn’t be difficult to start adding those heart rates together and turning them into a new health metric.
But does this really mean anything? This is where things get murkier. The study authors admit that their analysis was small and observational. They did not track the participants’ health outcomes, only the patterns of heart rate data. A high daily heart rate count could mean someone is active, or it could reflect anxiety, poor fitness, caffeine, or heat. Without context, the number itself tells us little.
However, the idea has intuitive appeal. Heart rate is one of the clearest windows into how our body is coping with the demands of life. A persistently high resting heart rate has been linked to an increased risk of heart disease, stroke and premature death.
Meanwhile, variability in the time between beats, known as heart rate variability, is a well-established indicator of stress and emotional well-being. Thinking in terms of “heart rate consumption” can help people visualize this connection between physical and mental load.
Athletes already know the power of this balance. Training too intensely, too often, can increase your resting heart rate, reduce heart rate variability and impair performance—a classic sign of overtraining.
Lighter sessions, called active recovery, where the heart rate remains low, are known to speed recovery, improve overall performance and stabilize mood. If a “heart rate budget” helped people realize when their heart is working too hard, it could encourage them to do lighter activities in the days before they reach exhaustion.
What the data doesn’t tell us
There are also implications for people living with chronic illnesses. Some health apps already use heart rate limits to help users avoid overexertion, especially when fatigue or cardiac strain may make recovery difficult. In this sense, tracking heart rate consumption could serve as a safety signal, rather than a competitive one, a way to know when the body needs to slow down.
But as with the brightest new ideas in fitness science, caution is needed. The authors of the study in JACC acknowledge that they used fitness tracker data from a small sample of highly trained cyclists and runners. This is a small sample of the population.
They didn’t measure blood pressure, oxygen levels or recovery biomarkers, all of which are important for heart health. Translate these findings into recommendations for everyday users smartwatches will require larger, long-term studies.
Then there’s the philosophical question: Should we really view heartbeats as a finite good? Exercise “spends” heartbeats in the short term, but often “gains” more life in the long term.
A long-distance runner’s heart may beat multiple times in a single day, but fewer times over a lifetime, because endurance training reduces resting heart rate and improves cardiac efficiency. In this sense, using the heart is not the problem, but not using it can be.
The consumption of heartbeats, at least for now, remains a metaphor in search of meaning. Yet it is a poetic metaphor. Regardless of your fitness tracker or smart watch start counting your total beats, the message behind this is simple: pay attention to your heart’s behavior throughout the day. It’s not about saving pace, but about spending it wisely.
*Tom Brownlee is an associate professor of sport and exercise science at the University of Birmingham
This content was originally published in The conversation. To access it, .
Source: Terra
Ben Stock is a lifestyle journalist and author at Gossipify. He writes about topics such as health, wellness, travel, food and home decor. He provides practical advice and inspiration to improve well-being, keeps readers up to date with latest lifestyle news and trends, known for his engaging writing style, in-depth analysis and unique perspectives.
