It may sound dramatic, but the rate at which your heart is beating plays a key role in how long you’re likely to live.
According to expert cardiologists and academic researchers, resting heart rate (also known as pulse rate) has become a simple, yet vitally important, biomarker in determining your state of heart and risk of disease.
So what exactly is resting heart rate, what’s normal, and what does it mean for your health?
What is a resting heart rate?
Put simply, doctors define a resting heart rate as being your number of heart beats per minute while sitting still and relaxing. “It can vary depending on things such as physical activity, caffeine intake and stress,” says Dr Nikita Patel, medical director at Vitality.
On average, most of us have a resting heart rate which varies between 60 and 100 beats per minute, a range which has long been considered as normal. However, some evidence has begun to suggest that if your resting heart rate is consistently above 80 beats per minute, it may leave you more vulnerable to certain diseases.
What is the impact of a higher resting heart rate?
Graham Rena, an endocrinology professor at the University of Dundee, says that a higher resting heart rate is associated with cardiovascular diseases and mortality from all causes, based on studies which have examined large populations of people. “Very high resting heart rate [more than 100 beats per minute] can also be a sign of illness such as atrial fibrillation,” he says.
One study which used data from more than 1.2 million people around the world, found that people with a resting heart rate above 80 beats per minute were 33 per cent more vulnerable to cardiovascular disease and 45 per cent more vulnerable to all chronic diseases, compared to those with a resting heart rate below 60.
Elite athletes can sometimes have remarkably low resting heart rates as a consequence of their extreme training. In the 1980s when at his peak as a two-time Olympic middle-distance gold medallist, Sebastian Coe had his resting heart rate measured at just 32 beats per minute.
However, for most of us, this would also be an indication of something badly wrong such as low blood pressure or heart valve problems. Patel says that unless you’re exercising a lot, it is not common for your resting heart rate to dip below 60
Why does your resting heart rate matter?
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Raised levels can be a sign of chronic stress
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Can lead to raised blood pressure and ultimately higher risk of stroke
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Can reveal underlying health conditions
To understand the importance of resting heart rate, Prof Tarv Dhanjal, a consultant cardiologist and professor of cardiology at the University of Warwick, says that we need to understand the physiological factors that determine how fast the heartbeats.
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Resting heart rate is regulated by the brain through the nervous system.
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Many chronic diseases can disrupt nervous system balance.
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Because of this, resting heart rate can reflect conditions like high blood pressure, diabetes and obstructive sleep apnoea.
The effect of hormones on heart rate
Prof Dhanjal explains that heart rate is driven in part by hormones such as dopamine, adrenaline and noradrenaline, which are released from glands within the body as part of the innate fight or flight response. “Your adrenal gland will release adrenaline or noradrenaline and that will provide you with the cardiac output required to allow your muscles and brain function at a high capacity,” says Prof Dhanjal.
The effect of the nervous system on heart rate
Heart rate can also be regulated directly by the brain through nerve fibres which connect the brain to the heart. There are two different nervous system responses which are activated, depending whether you’re relaxed or stressed, and either quicken or slow down your heart rate.
The so-called parasympathetic response, which is activated through yoga, meditation and general relaxation, helps to slow your heart down, while the sympathetic nervous system, which is activated by danger or stress, quickens your heartbeat.
People who are more easily agitated due to permanent work or family pressures, typically have an overactive sympathetic nervous system, a sign of chronic stress. Over time, this consistently high heart rate can lead to chronically raised blood pressure and ultimately a greater risk of heart attack and stroke.
How does your resting heart rate reveal underlying health conditions?
Prof Dhanjal explains that resting heart rate is often reflective of underlying disease which impacts vital bodily systems and organs, because this causes a disruption in the balance between the parasympathetic and sympathetic nervous system.
“High blood pressure, heart disease, heart failure, diabetes, obstructive sleep apnoea, all these conditions cause an upset in that balance, and they result in a greater sympathetic drive in the heart, increasing your heart rate,” he says.
How can people check their resting heart rate at home?
Dr Patel says that you can check your resting heart rate with a simple stopwatch, available on all smartphones. She recommends sitting down and resting for five to 10 minutes and following the below instructions.
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Rest your hand on a surface with your palm facing up, then place your index and middle fingers on the thumb side of your wrist. You should feel a pulse, which is a bit like a beating sensation. If you can’t feel anything, you may need to press a little firmer or adjust the position of your fingers.
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Set your timer for 60 seconds, then count the number of beats you feel until your timer goes off.
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The number of beats you’ve counted is your resting heart rate.
Many of the latest smartwatches such as the Masimo W1 and Apple Watch will automatically record your resting heart rate, while smart scales such as those manufactured by Withings, will do the same.
What causes a high resting heart rate?
According to Prof Dhanjal, a high caffeine intake, for example through regular consumption of energy drinks, can directly raise your heart rate, as well as a diet high in sugar and refined carbohydrates. “High-calorie foods can increase your resting heart rate, while stimulants like caffeine can also have a direct impact on your heart rate,” he says.
A high stress lifestyle and a lack of exercise can also impact your resting heart rate, but Prof Rena says that recent studies have also revealed that genetics plays a certain role in determining how fast your heart beats.
How do you lower your resting heart rate?
Prof Dhanjal recommends a diet which provides a more stable energy delivery over the course of the day, which can help bring your resting heart rate down. For example, he recommends three meals accompanied by small snacks, offering a balance of complex carbohydrates such as whole grains and beans, along with meat, fibre and vegetables.
However he says that forms of aerobic exercise such as running or swimming (that ironically raise your heart rate) are perhaps the most effective means of doing this, through improving the underlying fitness of your heart and the tone of your nervous system. “You find that peak heart rate is higher in athletes, because their hearts are primed to react to that sympathetic response,” says Prof Dhanjal.
However, it’s not necessary to be an Olympian to achieve a good resting heart rate. Prof Rena says that there is some evidence that more modest levels of physical activity, spread throughout the day, might lower resting heart rate.
Examples include getting up from your desk for a five-minute walk every couple of hours, doing a yoga class at lunchtime, or going for an evening stroll after dinner.
“Maintaining a healthy BMI of less than 25, by avoiding energy-dense foods high in fat, sugar and salt, will also be likely to lower resting heart rate,” he says.
When to see a doctor
Dr Patel says that if you have a low resting heart rate accompanied by symptoms such as tiredness, dizziness or fainting, you should see your GP.
Because of the demand on the NHS, Prof Dhanjal says that a GP consultation would not be offered based on a resting heart rate value alone, unless there were additional symptoms, such as atrial fibrillation which refers to periods of very rapid heartbeats.
However, Prof Dhanjal believes resting heart rate should be taken more seriously, and when he sees patients, he will test for this metric and investigate further if necessary.
“Resting heart rate should be taken seriously, because anything that can reduce your longevity should be taken seriously,” he says. “In patients I see, I certainly do tests on them to determine their resting heart rate, their heart rate variability, determine whether there’s any evidence of end organ damage, and give advice and guidance on how they can improve their resting heart rate.”
Source Agencies
