#236 Circadians + Ultradians

The Rhythms of Life

At this stage, we’re all familiar with the idea of “circadian” rhythms.

The word comes from the Latin circa + dies which literally means “around a day.” A ton of our biological processes are tied to 24-hour cycles.

(Of course, most of us IGNORE the natural rhythms baked into a day but we’ll save that for another discussion.)

Today’s focus: Have you ever heard of “ultradian rhythms”?

Ultra means “beyond.” “Ultradian” is a word coined in the 60’s and means “beyond the frequency of circadian rhythms”—meaning, more often than every 24 hours.

Specifically, ultradian rhythms refer to periods of about 90 minutes.

Here’s what we need to know: Research shows that our upper threshold for peak performance in any given burst is about 90 minutes.

After 90 minutes without a break, our performance begins to atrophy. Of course, we can move past this point via caffeine or sugar or by turning on our own stress hormones but we’d be much wiser to recognize the natural limit and then take a break.

We’ve gotta know that when we ignore our ultradian rhythms, we experience what researchers call “endurance stress.” Do that often enough and get ready for chronic fatigue and depression to go along with that reduced performance.


Today’s +1.

Cap your work bursts at 90 minutes. Then take a break for 15-20 minutes.

And, remember: Not all breaks are created equal. When you’re taking a break, take a real break! Get offline and go for a walk or just relax. Hopping on Facebook or surfing the web does not give you the optimal recovery you need to come back strong.

Circadians. Ultradians.

Let’s remember the rhythms of life.