Edgar Allan Poe’s 1843 masterpiece “The Tell-tale Heart” describes it as “a low, dull, quick sound—much such a sound as a watch makes when enveloped in cotton”. Thump. Thump. Thump. Like the ground beneath us, our heartbeat is ubiquitous. We only notice is when it gives way. But even in the absence of pathology, a resting heart rate is a key measure of health, telling much about who, and how healthy, we are.
Our hearts beat slowest when we are at rest. The number of beats per minute when a body is still called your resting heart rate (RHR). This is the optimal measure risk factor for cardiovascular mortality, doctors recommend it be measured often. An increase of 20 beats per minute is associated with heightened mortality (risk of death), even within the normal range.
The normal range is 60 to 100 beats per minute. Unless you are an elite athlete, an RHR of less than 60 beats (bradycardia) can signify a serious health condition. Beats over 100 (up to 400 beats per minute) are called tachycardia. This can also be serious.
Our RHR is regulated by the sinus node, which generates electrical impulses to regulate our heart. Regular exercise improves the heart’s efficiency. Superbly conditioned individuals have lower RHR, usually 40 to 60 beats per minute (BPM). Tour de France cyclist Miguel Indurain had a measured RHR of 28 beats per minute, although even that is not the world record.
Factors that affect RHR
Numerous factors affect RHR, which is why regular measurement is key. Fitness, activity, gender, age, size, disease, and stress can impact your RHR, as will transient circumstances such as room temperature, body position, medications or caffeine. Recent research shows heart rate also has a genetic component.
Traditionally the amateur athlete or health enthusiast measured his heart beat with two fingers and simple math. Wearables like Biostrap now enables us to get accurate easy accountings of our RHR over time. This lets us track the impact of our health, including the relative success of exercise or other interventions we’ve undertaken.
French mathematician Blaise Pascal said, “The heart has its reasons of which reason knows nothing.” From a biological perspective, that’s no longer true. Health researchers now have an increased understanding of what a healthy heart looks, sounds and acts like. And the more we learn, the more we understand that RHR is a fundamental marker of health that we can, and should measure at home.