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Internal Time: Chronotypes, Social Jet Lag, and Why You're So Tired Hardcover – April 30, 2012

ISBN-13: 978-0674065857 ISBN-10: 0674065859 Edition: Tra
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Editorial Reviews


Internal Time is an accessible, up-to-date overview of a subject that is important to all of us. With its remarkable depth and breadth of coverage, this book should be of interest to a wide and diverse audience. (Martin Zatz, Editor, Journal of Biological Rhythms)

This is a wonderful book from a gifted scientist, thinker and writer that provides the reader with the rare opportunity to discover something new about themselves and the world in which they live. (Russell G. Foster, University of Oxford)

In Internal Time, Till Roenneberg, a chronobiologist at the Ludwig-Maximilians University in Munich, Germany, takes readers on a journey through this mysterious area of science. He explores why some people are larks and others owls, why jet lag can be so debilitating to travelers, and why teenagers struggle to get out of bed in the morning...Roenneberg is a knowledgeable guide, with a talent for making difficult concepts clear and convincing...This is a fascinating introduction to an important topic, which will appeal to anyone who wishes to delve deep into the world of chronobiology, or simply wonders why they struggle to get a good night's sleep. (Richard Wiseman New Scientist 2012-04-28)

Time really is of the essence, says medical psychologist Till Roenneberg. By neglecting our body clocks--which rarely run in synchrony with the crazily cranked-up pace of modern life--we can develop "social jetlag," endangering our health and careers. Roenneberg has built his book on decades of research in everything from fungi and single-celled organisms to humans. In brilliantly minimalist terms, he explains the temporal mismatches behind teen exhaustion, early birds and night owls, and sleep phobia. (Nature 2012-04-01)

Internal Time is a cautionary tale--actually a series of 24 tales, not coincidentally. Roenneberg ranges widely from the inner workings of biological rhythms to their social implications, illuminating each scientific tutorial with an anecdote inspired by clinical research...Written with grace and good humor, Internal Time is a serious work of science incorporating the latest research in chronobiology...[A] compelling volume. (A. Roger Ekirch Wall Street Journal 2012-04-27)

Till Roenneberg's book is an engaging and informative layman's introduction to circadian science and its implications for contemporary humans...By integrating quality scientific exposition with well-rounded human vignettes, Roenneberg's book shows how sophisticated human behaviors arise partly from our embodied earthly nature. (Greg Murray Times Higher Education 2012-05-03)

Internal Time made me think deeply about what it means to be a time-bound organism: about the ways we live in time and the ways time lives in us. It is, in an unusually literal sense, a book about what makes us tick. (Kathryn Schulz New York 2012-04-29)

A brilliant book. (William Leith Telegraph 2012-05-31)

Fascinating...Other books have dealt with our biological clocks, but Roenneberg focuses on the ways in which societal pressures seem to be leading us to disregard our clocks, at considerable cost. (Rob Dunn Wilson Quarterly 2012-06-01)

About the Author

Till Roenneberg is Professor at the Institute of Medical Psychology at the Ludwig-Maximilians University, Munich.

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Product Details

  • Hardcover: 288 pages
  • Publisher: Harvard University Press; Tra edition (April 30, 2012)
  • Language: English
  • ISBN-10: 0674065859
  • ISBN-13: 978-0674065857
  • Product Dimensions: 1.2 x 5.8 x 8.5 inches
  • Shipping Weight: 1 pounds (View shipping rates and policies)
  • Average Customer Review: 4.5 out of 5 stars  See all reviews (22 customer reviews)
  • Amazon Best Sellers Rank: #410,704 in Books (See Top 100 in Books)

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Customer Reviews

4.5 out of 5 stars
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Most Helpful Customer Reviews

Format: Hardcover Verified Purchase
First off, I am not a subject matter expert in the realm of "chronobiology". But what Ronneberg describes in this short and very readable introduction to our internal body clocks was my life for the last third of my 30-year military career. As a result, while I can't recommend the book from the researcher angle, I can highly recommend the book from the subject angle. In short, I'm a fan and HIGHLY recommend this book.

Bottom line, Ronneberg's thesis is this: our body clock(s) is(are) real, performs(perform) very important calibrating functions and messing with it(them) has very serious consequences. And from personal experience, I would have to agree. I violated pretty much every "rule" in his book and I wound up paying a very heavy price. Fortunately (though it didn't seem so at the time), mandatory retirement arrived and an inability to go back to work in a second career provided an opportunity to get my clock(s) resynchronized (though not having yet read the book, I had no idea what I was doing other than following what my body was telling me I needed to do).

So what did I do wrong? Well, my work generally entailed long hours in a windowless, fluorescent-lighted, office (no connection with the natural light/dark cycle); too-often, middle-of-the-night phone calls (interrupted sleep cycles); frequent trips across up to 8-10 timezones where I was expected to be at work "bright & early" the day after travelling (unending two-way jet lag); and meetings/events at all hours of the day lasting anywhere from one hour to all day ("social jet lag").
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10 of 10 people found the following review helpful By AngliGreek on February 25, 2013
Format: Hardcover Verified Purchase
The author takes scientific studies and data, and makes them highly accessible. He transforms their results into clever postmodern parables about how we live our lives, to show why so many of us are out of sync with the itinerary of our minds and bodies. He looks at what makes some folks 'morning' people and others 'night' people; why and how we sleep; how our internal time clocks affect the degree to which we experience pain, when we feel like eating or being intimate; and why many of us are barely making it through our day jobs.

Roenneberg also tackles the unreasonable expectations of our culture, what really happens to us when we travel, and how people and animals respond to changes like Daylight Savings Time. The book was so fascinating, I couldn't put it down!
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9 of 9 people found the following review helpful By Fiona Leonard on September 20, 2013
Format: Kindle Edition Verified Purchase
There are some books that immerse you in a topic and you come away feeling wiser and inspired. Then there are other books that lead you to the edge of learning, throw you a few tasty morsels and then turn off the lights and send you away. For me, Internal Time: Chronotypes, Social Jet Lag and Why You're So Tired, sits squarely in the latter category.

This is a book about the science of sleep. According to the science, sleep is not something that is governed entirely by choice. Instead, it is something deeply rooted at our cellular level. While we have control over when we want to wake and sleep, at our core there is a mechanism that has preset when we should wake and sleep. Not only does this impact on how we feel, but also how we digest, think and function. This sleep preset is, however, not fixed, rather it follows a natural pattern over the course of our lives - varying with age. There is also a divergence between male and female sleeping patterns.

As the book clearly sets out, how we should sleep is profoundly affected by our need to conform to social expectations, whether those are preconceived notions of effectiveness ("the early bird catches the worm") or simply by the fact that we are required to be at work or school at a proscribed time.

The book is set out in 24 chapters (yes because there are 24 hours in a day) and each one begins with a case study/story and then goes on to explain the science behind it. The chapters makes for fascinating reading and there were plenty of sections that I found enlightening and highlighted to come back to. I read this book quite quickly because I was looking forward to getting to the advice section - "Here's how to manage sleep/jet lag/chronotypes etc" - except that part never comes.
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8 of 8 people found the following review helpful By Vikrum Sequeira on December 20, 2012
Format: Hardcover Verified Purchase
I saw a link to this book in a science blog and ordered it. It is a fascinating read - the author illustrates his points about different chronotypes with stories of people's sleep patterns. There is a scientific basis for morning people and night people. And not surprisingly, the factors that go into a person's chronotype are complex and range from genetics to season to stress levels to a person's age. One part I found particularly interesting was the author's examination of the fact that we live in a world of (ideally) 8 hours of continuous sleep followed by 16 hours of being continuously awake. The author shows how this crono-phenomenon is the result of industrialization, electricity, and the modern work force; this has not been the norm for most of our species' existence. I also enjoyed some of the descriptions of different sleep experiments. One of the better books out there on sleep, cronotypes, and our relationship to sleep/time.
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