The following Mark's Daily Apple article was written by Marksissons

and is narrated by Brock Armstrong.

Have you checked your heart rate variability lately?

People are always looking for that one biomarker to rule them all,

the number on a paper that absolutely determines your health, longevity, fitness level,

sex appeal, happiness, and productivity. Throughout the years, it's bounced around as

researchers think they've found it. From cholesterol to LDL to BMI to small dense LDL to CRP, to blood

pressure, to pulse rate, and back again. But we've always come up wanting. The one biomarker

never pans out because biology is complex and irreducible to a single number. However, there is one biomarker showing

promise as a broad indicator of overall health and fitness, heart rate variability, HRV, or the

variation in the intervals between heartbeats. If your heartbeats like a metronome with intervals

of identical length between each pulse,

you have low heart rate variability.

This is bad.

If your heartbeats follow a more fractal pattern with beat intervals of varying lengths,

you have high heart rate variability.

This is good.

This probably sounds counterintuitive.

Most people assume that a steady,

consistent pattern of heartbeats is the healthiest. I mean, doesn't the human body need a steady,

consistent flow of blood and nutrients to its cells and tissues? But recall the musicians lament

about the drum machine, that it has no soul. The perfect metronomic unfoldment of the drum

...