Sleep Chronotypes: Optimize Your Sleep-Wake Cycle

Your Sleep Chronotype: Are You an Early Bird or Night Owl?

Walker and Huberman discuss the concept of chronotypes, which are individual variations in sleep timing preferences. Walker divides chronotypes into five categories: extreme morning type, morning type, neutral, evening type, and extreme evening type. Each chronotype has a preferred bedtime and wake time, ranging from 8 p.m. to 4:30 a.m. for extreme morning types, to 2-3 a.m. to mid-morning for extreme evening types.

To determine one’s chronotype, Walker suggests taking the Morningness-Eveningness Questionnaire (MEQ) online, which takes just a few minutes to complete. The questionnaire provides a score that categorizes individuals into one of the five chronotypes.

Huberman admits that his preferred sleep schedule would be going to bed at 8:30 p.m. and waking up at 4:30 a.m., suggesting he may be an extreme morning type.

When Is Your Natural Sleep-Wake Cycle?

Walker and Huberman discuss the importance of chronotype, which is largely genetically determined and influences an individual’s natural sleep-wake cycle. Huberman shares that he feels best when going to sleep around 90-120 minutes after sundown and waking up around 4:30-5:00 a.m.

Walker points out that society is biased towards morning types and often stigmatizes evening types as lazy or unproductive. He emphasizes that chronotype is not a choice and is determined by at least 22 different genes.

The discussion highlights the unfairness of judging someone based on their chronotype, as it is a genetically predetermined trait, much like eye color. Walker stresses the importance of understanding and respecting an individual’s natural sleep-wake cycle for their overall well-being and productivity.

Why Timing Your Sleep Matters for Your Chronotype

Huberman, a self-described morning type, often struggles to stay asleep when he goes to bed later than his natural circadian rhythm. Even if he falls asleep easily at midnight, he frequently wakes up around 3:30 or 4:00 in the morning, unable to fall back asleep.

Walker explains that this is because Huberman’s circadian rhythm is on its upswing in the early morning hours, preventing him from sleeping longer. On the other hand, evening types who are forced to go to bed earlier than their natural rhythm often experience sleep onset insomnia, struggling to fall asleep.

When people sleep out of sync with their chronotype, the quality of their sleep suffers, even if they have the same opportunity for sleep quantity. Walker emphasizes that aligning one’s sleep window with their chronotype is crucial for achieving good sleep, as fighting against biology often leads to disease and sickness.

Peak Physical Performance Times Vary by Chronotype

Walker and Huberman discuss how peak alertness and physical ability vary throughout the day based on an individual’s chronotype. Huberman mentions that his peak performance window falls between 10:00 a.m. and noon.

Walker suggests that if Huberman were to perform the same workout routine at different times of the day, there would be definitive periods when he is at his optimal performance level. He hypothesizes that the optimality of the brain is matched by the optimality of the body, meaning that Huberman’s peak jump height or muscle strength would likely coincide with the time periods that fit his circadian chronotype rhythmicity.

More From this Episode

Leave a Comment