Are you sitting comfortably? If so, put out one hand so you’re looking at your palm, then use the first and middle fingers of your other hand to feel for the pulse on the inside of your wrist. Count the beats for 60 seconds, and that’s your heart rate. Assuming you’re resting rather than exercising or stressed, it will probably be somewhere between 60 and 100 beats a minute. But what does it mean if it’s at the top or bottom of the range – or even outside it?
We’ve known about the connection between heart rate and health for thousands of years. Herophilus of Alexandria (325-255 BC), sometimes known as the father of anatomy, designed a water clock to time the pulse, at around the same time that Chinese physicians were using its strength and regularity to diagnose disease. A couple of centuries later, Roman Greek surgeon Galen nudged things along by watching recently deceased gladiators’ hearts beat their last, going on to write: “Exercise to begin with – and so long as it is practised in moderation – renders the pulse vigorous large, quick, and frequent. Large amounts of exercise, which exceed the capacity of the individual, make it small, faint, quick and extremely frequent.” Since then, physicians and scientists have been hard at work on different ways to track our heart rate, as well as the variations within it. What do the measurements actually tell us?
