A guide to using the science of the body clock to promote better sleep, better health, and better thinking “Full of surprising and useful facts. . . . Unlike many science books with similar subtitles, it really might ‘revolutionise’ your life.”—James McConnachie, Times (UK) “A comprehensive manifesto for living in harmony with our body clocks, penned by someone who has devoted his career to studying them.”—Financial Times Biological clocks are embedded in every aspect of human biology, guiding us toward the prime times of day to sleep, eat, think, and work. Award-winning scientist Russell Foster brings decades of study to this journey through the circadian rhythms that dominate our days and nights. He shows how the realities of 24/7 life—including night-shift work, overbooked calendars, and caring for newborns—disrupt the body clock, taking a toll on sleep and on mental and physical health. By dismantling long-standing myths and citing cutting-edge science, Foster empowers readers to get back into rhythm and live healthier, sharper lives: scheduling meals to prevent obesity and diabetes; timing medications to increase their effectiveness; getting better sleep through exposure to natural light; and much more. “If you want to embrace life,” Foster writes, “then embracing biological time will help you do this.”