The complete runner’s guide to resting heart rate

The use of heart rate monitors is now common among many runners – but how much do we really know about resting heart rate? A lower resting heart rate, an indicator of aerobic fitness, generally implies more efficient heart function. But are there exceptions and what warning signs should runners look for? RW spoke to leading sports cardiologist Dr. Dan Augustine to find out more.

What is a normal resting heart rate?

“The average resting heart rate in the general population will range between 60-100 beats per minute (bpm). I think it’s fair to say that the lower that is, generally the fitter you are. In those who train, I would expect heart rates to be much closer to 60 beats per minute, and it is not uncommon for recreational runners to have heart rates in the 40s.”

Is a high or low heart rate cause for concern?

“It’s about how you feel with that heartbeat. So if you have a resting heart rate of 90, but you feel good about your daily activities, I’m not worried.

“But if you have abnormal symptoms at rest, such as disproportionate shortness of breath, you should get it checked out.” Another concern is people with cardiac arrhythmias who get disproportionately high heart rates for the amount of exercise they are doing. For example, where you would expect their heart rate to be around 140, it is 180 and remains high for some time after stopping exercise or reducing exercise intensity. We should also not feel dizzy or faint while exercising, especially if we increase the intensity of the exercise. So if this happens, it’s something to check out.

“For people with a low heart rate, a symptom to watch for is if you start to feel dizzy or pass out. That is unusual and you should seek advice. So I’m more concerned about the symptoms associated with the heart rate than just the number itself.”

What effect does gender have on resting heart rate?

The average resting heart rate of a woman is slightly higher than the average resting heart rate of a man. The average man has about 70 beats per minute; the average woman is a few beats per minute higher. This is largely due to the difference in size between men and women: women’s hearts are slightly smaller, so they beat slightly faster to reach the required cardiac output.’

What effect does age have on resting heart rate?

“When you’re an adult, the resting rate doesn’t vary much with age. What varies is your peak heart rate. There are few ways to try to calculate your peak heart rate, some more accurate than others. The equation “220 minus your age” was first described in the 1970s and is not intended to be applied strictly because it contains errors. In younger people, it probably overestimates what your peak heart rate should be. In older people, it probably underestimates what your peak heart rate should be.”

Why is it important that your heart rate is not too high?

“What you have to consider is what causes it to be high. If there is a medical condition that causes it to be high, such as anemia or an overactive thyroid gland, that will cause a faster heartbeat. Sometimes a faster heart rate can be a sign that something else is going on. Then it comes down to your efficiency. At rest, your heart is not supposed to have a cardiac output of 8 liters [the average is 3-4 litres per minute], but if you have a very high heart rate, it causes high cardiac output. So you have to find out why that is.’

How can you lower your resting heart rate?

‘There is not one thing that stands alone, but moving certainly helps. In general, getting fitter through aerobic exercise will lower resting heart rate in most cases, depending on how much you’re doing. We know that if you do aerobic exercise regularly, probably more than three hours a week, the heart will begin to adapt and undergo physiological changes. One is usually a decrease in resting heart rate. There are a few reasons why the heart rate drops the more you do aerobic exercise. These include making the heart bigger so the heart doesn’t have to beat as fast to increase cardiac output. We also all have a pacemaker in our heart – called the sinus node – and through regular exercise, the sinus node is believed to downregulate slightly and lower the heart rate. In addition, exercise can strengthen part of the nervous system, something called parasympathetic or vagal tone, which can lower resting heart rate.”

What is the effect of diet, sleep and stress on resting heart rate?

“Anything that disrupts physiology — whether that’s poor nutrition, lack of sleep, or physical and emotional stress — can affect resting heart rate and cause it to be higher.” Our ‘rest’ time when we don’t train can often be neglected, but it’s really important to find the right balance from a physical and psychological perspective. That includes getting enough sleep, identifying stressors in our lives and adjusting them as much as possible. From a general health perspective, it is important to eat a healthy diet as well. Factors such as eating fruits, vegetables, whole grains and controlling alcohol consumption will all contribute to a healthy physiology and a lower heart rate in the longer term.”

Dr. Dan Augustine is a sports cardiologist:

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