“Respecting our natural bodily rhythms really, really matters. . . . This is an exemplary popular science book in many ways. It is readable. Full of surprising and useful facts. Rigorously evidence-based (there are no fewer than 921 references, all safely corralled at the back). Unlike many science books with similar subtitles, it really might ‘revolutionise’ your life.”—James McConnachie, The Times (London)

“A comprehensive manifesto for living in harmony with our body clocks, penned by someone who has devoted his career to studying them.”―Financial Times

“Life Time should certainly be mandatory reading for night-shift workers, but its messages are so universal that it would be hard not to gain some sleep smarts from its pages, whoever you are.”—Alex Wilkins, New Scientist

“Almost all of us would benefit from this revelatory guide by a world-leading expert on circadian neuroscience.”—The Bookseller, Editor’s Choice

“A superlative guide to some of the most intriguing questions of human existence.”—Bill Bryson, bestselling author of A Short History of Nearly Everything

“This book has the answers to everything you’ve ever wondered about your natural rhythms, from sleep to eating to exercise. Excellent, engaging and evidence-based, it’s a brilliant guide to an aspect of our health we don’t think about enough.”—Claudia Hammond, author of The Art of Rest

“Strongly recommended. You will sleep more deeply, be awake more fully, and live much more harmoniously with Russell Foster’s help.”—Anthony Seldon, author of The Impossible Office?: The History of the British Prime Minister

“Life Time not only communicates but also translates the science of body clocks and sleep: using the insights and advice in this book, readers may improve health, happiness and wellbeing in our 24/7 society.”—Thomas C. Erren, MD, University of Cologne