BeFreed
    Categories>Health>The Lost Rhythm of Segmented Sleep: History of First and Second Sleep

    The Lost Rhythm of Segmented Sleep: History of First and Second Sleep

    15 分钟
    |
    |
    2026年5月23日
    HealthHistoryScience

    Explore the history of segmented sleep and the shift from first and second sleep to the modern eight-hour block. Learn how the Industrial Revolution changed our rhythm.

    The Lost Rhythm of Segmented Sleep: History of First and Second Sleep

    The Lost Rhythm of Segmented Sleep: History of First and Second Sleep最佳语录

    “

    We’ve become so obsessed with getting that 'perfect' eight-hour block of sleep that we’ve forgotten it’s actually a very recent invention; for most of human history, people slept in two distinct segments with a purposeful gap of wakefulness in the middle.

    ”

    此音频课程由 BeFreed 社区成员创建

    输入问题

    Create a lesson on the history of human sleep patterns from ancient times to today. Explain segmented sleep (‘first sleep’ and ‘second sleep’), siesta cultures, monophasic and polyphasic sleep. Include how artificial lighting and industrialization changed sleep habits, the psychological and biological benefits of each pattern, and compare which sleep style may work best for modern humans.

    主持声音
    Milesplay
    Jacksonplay
    学习风格
    深度
    知识来源
    Segmented Sleep, by A. Roger Ekirch
    link
    https://harpers.org/archive/2013/08/segmented-sleep/
    Why we used to sleep in two segments – and how the modern shift changed our sense of time
    link
    https://theconversation.com/why-we-used-to-sleep-in-two-segments-and-how-the-modern-shift-changed-our-sense-of-time-267909
    The myth of the eight-hour sleep - BBC News
    link
    https://www.bbc.com/news/magazine-16964783
    Are humans facing a sleep epidemic or enlightenment? Large-scale, industrial societies exhibit long, efficient sleep yet weak circadian function
    link
    https://pmc.ncbi.nlm.nih.gov/articles/PMC11858753/
    What is a siesta? The history of the afternoon nap and its benefits.
    link
    https://nz.news.yahoo.com/siesta-151231067.html
    From ‘pajamas and the chamber pot’ to the ‘coffee nap’: In search of the perfect siesta | Lifestyle | EL PAÍS English
    link
    https://english.elpais.com/lifestyle/2026-02-08/from-pajamas-and-the-chamber-pot-to-the-coffee-nap-in-search-of-the-perfect-siesta.html

    常见问题

    Segmented sleep, also known as biphasic sleep, was the historical norm before the Industrial Revolution. According to historian A. Roger Ekirch, people typically slept in two distinct periods known as first sleep and second sleep. Instead of one continuous eight-hour block, individuals would wake up in the middle of the night for a period of wakefulness to socialize, reflect, or perform light tasks before returning to bed for their second rest.

    A. Roger Ekirch is a historian who spent years researching old diaries and medical texts to understand human sleep habits. He discovered that for most of human history, people did not sleep in one long stretch. His research highlights that the modern obsession with a single eight-hour block is a relatively recent invention, and that our ancestors naturally followed a rhythm of segmented sleep with a purposeful gap of wakefulness in between.

    The Industrial Revolution marked a major shift in how humans perceive time and manage their biological clocks. Before this era, waking up at 2:00 a.m. was seen as a natural 'watch' rather than a medical problem. As society moved toward standardized work hours and artificial lighting, the traditional rhythm of first and second sleep was replaced by the modern expectation of a single, uninterrupted block of rest, leading many to view natural wakefulness as insomnia.

    发现更多

    Learn stable AM/PM routines for better sleep
    学习计划

    Learn stable AM/PM routines for better sleep

    Consistent sleep routines are foundational to physical health, cognitive function, and emotional wellbeing, yet many people struggle with disrupted sleep patterns. This learning plan helps anyone experiencing sleep difficulties or energy fluctuations establish science-backed daily routines that work with their body's natural rhythms.

    4 h 30 m•4 章节
    Rebuild Your Broken Sleep
    学习计划

    Rebuild Your Broken Sleep

    This plan is essential for chronic insomniacs and anyone stuck in a cycle of sleep-related anxiety. It provides a structured behavioral approach to move beyond temporary fixes and restore a natural, effortless sleep cycle.

    30 m•5 章节
    I want to learn how to fall asleep quickly
    学习计划

    I want to learn how to fall asleep quickly

    Modern stress and digital distractions have disrupted our natural ability to rest, making sleep onset a common struggle. This guide is essential for professionals and restless sleepers who want to master the science of relaxation and reclaim their nights through proven psychological and environmental shifts.

    4 h 2 m•4 章节
    Overcome insomnia
    学习计划

    Overcome insomnia

    Insomnia affects millions of people and can seriously impact mental health, productivity, and overall quality of life. This learning plan is designed for anyone struggling with difficulty falling asleep, staying asleep, or waking too early, offering evidence-based solutions that address both the psychological and practical dimensions of sleep problems. Whether you experience occasional sleep disruptions or chronic insomnia, these structured approaches can help you reclaim restful nights without relying on medication.

    5 h 25 m•4 章节
    Design Your Ideal Daily Rhythm
    学习计划

    Design Your Ideal Daily Rhythm

    In an era of constant burnout, mastering your time is essential for sustained productivity and well-being. This plan is designed for busy professionals and creatives who feel overwhelmed by their schedules and need a science-backed approach to reclaiming their day.

    1 h 36 m•4 章节
    Rhythm of Existence: Sustainable Daily Flow
    学习计划

    Rhythm of Existence: Sustainable Daily Flow

    In an era of constant burnout, mastering sustainable productivity is essential for long-term success. This plan is designed for overwhelmed professionals and creatives who need to transition from chaotic reactivity to a structured yet flexible daily rhythm.

    2 h 41 m•3 章节
    Biohack my sleep for oeak daily energy
    学习计划

    Biohack my sleep for oeak daily energy

    In an era of chronic burnout, mastering your rest is the ultimate competitive advantage. This plan is designed for high-performers and professionals who want to leverage biological science to eliminate fatigue and unlock peak daily energy.

    4 h 29 m•4 章节
    Sleep early, recover, and align rhythm.
    学习计划

    Sleep early, recover, and align rhythm.

    This learning plan is essential for high-performers and anyone struggling with burnout or irregular sleep patterns. It provides a science-backed framework to transform rest into a competitive advantage by mastering biological timing and recovery habits.

    4 h 53 m•4 章节

    由哥伦比亚大学校友在旧金山创建

    BeFreed 汇聚了全球超过 1,000,000 求知若渴的学习者
    查看更多网络上关于 BeFreed 的讨论

    "Instead of endless scrolling, I just hit play on BeFreed. It saves me so much time."

    @Moemenn
    platform
    star
    star
    star
    star
    star

    "I never knew where to start with nonfiction—BeFreed’s book lists turned into podcasts gave me a clear path."

    @Chloe, Solo founder, LA
    platform
    comments
    12
    likes
    117

    "Perfect balance between learning and entertainment. Finished ‘Thinking, Fast and Slow’ on my commute this week."

    @Raaaaaachelw
    platform
    star
    star
    star
    star
    star

    "Crazy how much I learned while walking the dog. BeFreed = small habits → big gains."

    @Matt, YC alum
    platform
    comments
    12
    likes
    108

    "Reading used to feel like a chore. Now it’s just part of my lifestyle."

    @Erin, Investment Banking Associate , NYC
    platform
    comments
    254
    likes
    17

    "Feels effortless compared to reading. I’ve finished 6 books this month already."

    @djmikemoore
    platform
    star
    star
    star
    star
    star

    "BeFreed turned my guilty doomscrolling into something that feels productive and inspiring."

    @Pitiful
    platform
    comments
    96
    likes
    4.5K

    "BeFreed turned my commute into learning time. 20-min podcasts are perfect for finishing books I never had time for."

    @SofiaP
    platform
    star
    star
    star
    star
    star

    "BeFreed replaced my podcast queue. Imagine Spotify for books — that’s it. 🙌"

    @Jaded_Falcon
    platform
    comments
    201
    thumbsUp
    16

    "It is great for me to learn something from the book without reading it."

    @OojasSalunke
    platform
    star
    star
    star
    star
    star

    "The themed book list podcasts help me connect ideas across authors—like a guided audio journey."

    @Leo, Law Student, UPenn
    platform
    comments
    37
    likes
    483

    "Makes me feel smarter every time before going to work"

    @Cashflowbubu
    platform
    star
    star
    star
    star
    star

    由哥伦比亚大学校友在旧金山创建

    BeFreed 汇聚了全球超过 1,000,000 求知若渴的学习者
    查看更多网络上关于 BeFreed 的讨论

    "Instead of endless scrolling, I just hit play on BeFreed. It saves me so much time."

    @Moemenn
    platform
    star
    star
    star
    star
    star

    "I never knew where to start with nonfiction—BeFreed’s book lists turned into podcasts gave me a clear path."

    @Chloe, Solo founder, LA
    platform
    comments
    12
    likes
    117

    "Perfect balance between learning and entertainment. Finished ‘Thinking, Fast and Slow’ on my commute this week."

    @Raaaaaachelw
    platform
    star
    star
    star
    star
    star

    "Crazy how much I learned while walking the dog. BeFreed = small habits → big gains."

    @Matt, YC alum
    platform
    comments
    12
    likes
    108

    "Reading used to feel like a chore. Now it’s just part of my lifestyle."

    @Erin, Investment Banking Associate , NYC
    platform
    comments
    254
    likes
    17

    "Feels effortless compared to reading. I’ve finished 6 books this month already."

    @djmikemoore
    platform
    star
    star
    star
    star
    star

    "BeFreed turned my guilty doomscrolling into something that feels productive and inspiring."

    @Pitiful
    platform
    comments
    96
    likes
    4.5K

    "BeFreed turned my commute into learning time. 20-min podcasts are perfect for finishing books I never had time for."

    @SofiaP
    platform
    star
    star
    star
    star
    star

    "BeFreed replaced my podcast queue. Imagine Spotify for books — that’s it. 🙌"

    @Jaded_Falcon
    platform
    comments
    201
    thumbsUp
    16

    "It is great for me to learn something from the book without reading it."

    @OojasSalunke
    platform
    star
    star
    star
    star
    star

    "The themed book list podcasts help me connect ideas across authors—like a guided audio journey."

    @Leo, Law Student, UPenn
    platform
    comments
    37
    likes
    483

    "Makes me feel smarter every time before going to work"

    @Cashflowbubu
    platform
    star
    star
    star
    star
    star

    "Instead of endless scrolling, I just hit play on BeFreed. It saves me so much time."

    @Moemenn
    platform
    star
    star
    star
    star
    star

    "I never knew where to start with nonfiction—BeFreed’s book lists turned into podcasts gave me a clear path."

    @Chloe, Solo founder, LA
    platform
    comments
    12
    likes
    117

    "Perfect balance between learning and entertainment. Finished ‘Thinking, Fast and Slow’ on my commute this week."

    @Raaaaaachelw
    platform
    star
    star
    star
    star
    star

    "Crazy how much I learned while walking the dog. BeFreed = small habits → big gains."

    @Matt, YC alum
    platform
    comments
    12
    likes
    108

    "Reading used to feel like a chore. Now it’s just part of my lifestyle."

    @Erin, Investment Banking Associate , NYC
    platform
    comments
    254
    likes
    17

    "Feels effortless compared to reading. I’ve finished 6 books this month already."

    @djmikemoore
    platform
    star
    star
    star
    star
    star

    "BeFreed turned my guilty doomscrolling into something that feels productive and inspiring."

    @Pitiful
    platform
    comments
    96
    likes
    4.5K

    "BeFreed turned my commute into learning time. 20-min podcasts are perfect for finishing books I never had time for."

    @SofiaP
    platform
    star
    star
    star
    star
    star

    "BeFreed replaced my podcast queue. Imagine Spotify for books — that’s it. 🙌"

    @Jaded_Falcon
    platform
    comments
    201
    thumbsUp
    16

    "It is great for me to learn something from the book without reading it."

    @OojasSalunke
    platform
    star
    star
    star
    star
    star

    "The themed book list podcasts help me connect ideas across authors—like a guided audio journey."

    @Leo, Law Student, UPenn
    platform
    comments
    37
    likes
    483

    "Makes me feel smarter every time before going to work"

    @Cashflowbubu
    platform
    star
    star
    star
    star
    star

    "Instead of endless scrolling, I just hit play on BeFreed. It saves me so much time."

    @Moemenn
    platform
    star
    star
    star
    star
    star

    "I never knew where to start with nonfiction—BeFreed’s book lists turned into podcasts gave me a clear path."

    @Chloe, Solo founder, LA
    platform
    comments
    12
    likes
    117

    "Perfect balance between learning and entertainment. Finished ‘Thinking, Fast and Slow’ on my commute this week."

    @Raaaaaachelw
    platform
    star
    star
    star
    star
    star

    "Crazy how much I learned while walking the dog. BeFreed = small habits → big gains."

    @Matt, YC alum
    platform
    comments
    12
    likes
    108

    "Reading used to feel like a chore. Now it’s just part of my lifestyle."

    @Erin, Investment Banking Associate , NYC
    platform
    comments
    254
    likes
    17

    "Feels effortless compared to reading. I’ve finished 6 books this month already."

    @djmikemoore
    platform
    star
    star
    star
    star
    star

    "BeFreed turned my guilty doomscrolling into something that feels productive and inspiring."

    @Pitiful
    platform
    comments
    96
    likes
    4.5K

    "BeFreed turned my commute into learning time. 20-min podcasts are perfect for finishing books I never had time for."

    @SofiaP
    platform
    star
    star
    star
    star
    star

    "BeFreed replaced my podcast queue. Imagine Spotify for books — that’s it. 🙌"

    @Jaded_Falcon
    platform
    comments
    201
    thumbsUp
    16

    "It is great for me to learn something from the book without reading it."

    @OojasSalunke
    platform
    star
    star
    star
    star
    star

    "The themed book list podcasts help me connect ideas across authors—like a guided audio journey."

    @Leo, Law Student, UPenn
    platform
    comments
    37
    likes
    483

    "Makes me feel smarter every time before going to work"

    @Cashflowbubu
    platform
    star
    star
    star
    star
    star
    1.5K Ratings4.7
    开启你的学习之旅,就是现在
    BeFreed App
    BeFreed

    个性化学习,无所不能

    DiscordLinkedIn
    精选书籍摘要
    Crucial ConversationsThe Perfect MarriageInto the WildNever Split the DifferenceAttachedGood to GreatSay Nothing
    热门分类
    Self HelpCommunication SkillRelationshipMindfulnessPhilosophyInspirationProductivity
    名人书单
    Elon MuskCharlie KirkBill GatesSteve JobsAndrew HubermanJoe RoganJordan Peterson
    获奖作品
    Pulitzer PrizeNational Book AwardGoodreads Choice AwardsNobel Prize in LiteratureNew York TimesCaldecott MedalNebula Award
    精选主题
    ManagementAmerican HistoryWarTradingStoicismAnxietySex
    年度最佳书籍
    2025 Best Non Fiction Books2024 Best Non Fiction Books2023 Best Non Fiction Books
    精选作者
    Chimamanda Ngozi AdichieGeorge OrwellO. J. SimpsonBarbara O'NeillWinston ChurchillCharlie Kirk
    BeFreed 与其他应用对比
    BeFreed vs. Other Book Summary AppsBeFreed vs. ElevenReaderBeFreed vs. ReadwiseBeFreed vs. Anki
    学习工具
    Knowledge VisualizerAI Podcast Generator
    更多信息
    关于我们arrow
    定价arrow
    常见问题arrow
    博客arrow
    招聘arrow
    合作伙伴arrow
    大使计划arrow
    目录arrow
    BeFreed
    Try now
    © 2026 BeFreed
    使用条款隐私政策
    BeFreed

    个性化学习,无所不能

    DiscordLinkedIn
    精选书籍摘要
    Crucial ConversationsThe Perfect MarriageInto the WildNever Split the DifferenceAttachedGood to GreatSay Nothing
    热门分类
    Self HelpCommunication SkillRelationshipMindfulnessPhilosophyInspirationProductivity
    名人书单
    Elon MuskCharlie KirkBill GatesSteve JobsAndrew HubermanJoe RoganJordan Peterson
    获奖作品
    Pulitzer PrizeNational Book AwardGoodreads Choice AwardsNobel Prize in LiteratureNew York TimesCaldecott MedalNebula Award
    精选主题
    ManagementAmerican HistoryWarTradingStoicismAnxietySex
    年度最佳书籍
    2025 Best Non Fiction Books2024 Best Non Fiction Books2023 Best Non Fiction Books
    学习工具
    Knowledge VisualizerAI Podcast Generator
    精选作者
    Chimamanda Ngozi AdichieGeorge OrwellO. J. SimpsonBarbara O'NeillWinston ChurchillCharlie Kirk
    BeFreed 与其他应用对比
    BeFreed vs. Other Book Summary AppsBeFreed vs. ElevenReaderBeFreed vs. ReadwiseBeFreed vs. Anki
    更多信息
    关于我们arrow
    定价arrow
    常见问题arrow
    博客arrow
    招聘arrow
    合作伙伴arrow
    大使计划arrow
    目录arrow
    BeFreed
    Try now
    © 2026 BeFreed
    使用条款隐私政策

    核心要点

    1

    The Midnight Gap and the Forgotten Rhythms of the Past

    0:00
    0:32
    1:02
    1:22
    2

    First Sleep and the Sacred Hour of Wakefulness

    2:30
    3:00
    3

    The Biological Blueprint of the Biphasic Mind

    4:37
    4

    How Artificial Light Re-Engineered the Human Night

    6:35
    6:58
    5

    The Modern Paradox of Efficiency versus Rhythm

    8:03
    6

    The Siesta and the Biology of the Afternoon Slump

    9:17
    10:09
    7

    The Dangers of Forcing the "Uberman" Schedule

    11:27
    11:49
    8

    Navigating the 3:00 a.m. Wake-up Call

    13:18
    9

    Reclaiming Your Natural Rhythm in a Modern World

    14:45
    15:18

    相似内容

    The Rhythm of Being: Beyond the Clock 书籍封面
    Trying Not to TryThe Power of WhenBrain WashThe Emotional Life of Your Brain
    17 sources
    The Rhythm of Being: Beyond the Clock
    Explore the biological tug-of-war between our need for emotional spontaneity and the internal clocks that keep us sane. Learn how to escape 'permanent jet lag' by turning rigid schedules into soulful human rituals.
    25 min
    Breaking the Sleep Struggle: Your Dawn Revolution Starts Now 书籍封面
    The 5 AM Club
    1 source
    Breaking the Sleep Struggle: Your Dawn Revolution Starts Now
    Discover how The 5 AM Club methodology can transform your insomnia and late-sleeping habits by rewiring your circadian rhythms. Learn the science-backed Victory Hour protocol that turns early rising from struggle into natural habit.
    13 min
    The Cortisol Rhythm 书籍封面
    Relaxation techniques: Try these steps to lower stress - Mayo ClinicSix relaxation techniques to reduce stress - Harvard HealthHow To Lower Cortisol and Reduce StressCortisol Management: Science-Based Stress Reduction
    5 sources
    The Cortisol Rhythm
    When chronic stress breaks your natural biological clock, sleep and health suffer. Learn to reset your relaxation response and find your calm again.
    15 min
    Break the Snooze Trap for Good 书籍封面
    Set it & Forget itSleep SmarterSleep Science Secrets for Energy, Focus, and RestNight School
    21 sources
    Break the Snooze Trap for Good
    Stop the cycle of morning grogginess by understanding the science of sleep inertia and mastering a step-by-step protocol to reclaim your energy.
    31 min
    Night Shift and the Smartphone Loop 书籍封面
    Mechanisms that link circadian preference to problematic smartphone and social media use in young adults - PMCMental Health Survival Guide for Night Shift Workers | MyNighttime3 Things to Do If You Can’t Resist Your Stupid Little Phone Before Bed | SELFBlue Light, Screen Time, and Post-Shift Sleep: What Actua...
    6 sources
    Night Shift and the Smartphone Loop
    Graveyard shifts create a unique pull toward doomscrolling. Learn why your brain craves the screen at 3 a.m. and how to protect your mental health.
    18 min
    The Science of a Sustainable Morning 书籍封面
    Atomic HabitsWhy we sleepThis is the optimal morning routine, according to science | BBC Science Focus MagazineHow to Build a Sustainable Morning Routine: Science-Based Guide
    7 sources
    The Science of a Sustainable Morning
    Exhausted by extreme hustle-culture rituals? Learn how to align your first 90 minutes with your brain's biology to boost energy without the burnout.
    20 min
    Dangerously Sleepy Overworked Americans And The Cult Of Manly Wakefulness 书籍封面
    Dangerously Sleepy Overworked Americans And The Cult Of Manly Wakefulness
    Alan Derickson
    Explores how overwork and sleep deprivation became glorified in American culture, especially among men, despite serious health consequences.
    9 min
    Waking the tiger 书籍封面
    Waking the tiger
    Peter A. Levine & Ann Frederick
    Healing trauma through instinctual body awareness and natural healing processes.
    8 min