Ultradian rhythms: Understanding the three phases of great mental focus

Many of us are familiar with the circadian rhythm: the internal clock that governs our sleep-wake cycle. That rhythm takes some 24 hours, which is reflected in its name: “circa” is Latin for “about”, and “dies” means “day”.

As it turns out, there are also shorter rhythms that govern our days (and nights). These are called ultradian rhythms, with “ultra” meaning “beyond”. The most important ultradian rhythms last 90 minutes and break up both our sleeping and waking time. When asleep, we go through three phases (with light sleep, deep sleep and dream sleep) in a 90-minute cycle.

When awake, ultradian rhythms are vital for our productivity, especially our ability to focus deeply. Research shows that we can maintain intense focus for up to 90 minutes at a time. And just as we can’t get into deep sleep immediately after lying down, we can’t get into deep focus right after sitting down. Instead, we go through three phases:

Phase 1: Struggling towards focus
In the beginning, focusing always feels hard. In that phase, it’s most difficult for us to suppress our instinctive urges to distract ourselves or quit. Thus, we need to struggle towards focus. This phase usually takes 10-15 minutes.

Phase 2: Getting into focus (and flow)
Given we make it through the first phase, the second phase is where the magic happens. Maintaining focus and resisting distractions feels much less effortful, and we might even get into the flow state. This phase takes 45-60 minutes.

Phase 3: Hitting the focus limit
After some 55 to 75 minutes, our ability to maintain mental focus decreases again. At this point, the top-down control we need to resist distractions and stay focused has used up the mental energy available in that ultradian rhythm. This phase takes 10-15 minutes.

In previous editions of this newsletter, I’ve recommended scheduling focused bouts when you’re most alert, and minimizing distractions from technology and co-workers during those bouts. The final step to great mental focus is transitioning well through the three phases of your ultradian rhythm. Over the following weeks, I will share several effective practices to help you do just that. Stay tuned!