The Inner Clock: Living in Sync with Our Circadian Rhythms

The importance of circadian rhythms has been significantly underappreciated, according to this edifying debut examination. Science journalist Peeples explains that these rhythms are generated by the suprachiasmatic nucleus in the brain, which coordinates a cyclical system of biological processes that, among other functions, decrease body temperature and appetite at night while priming the body to digest and metabolize food during the day. Exploring the surprisingly far-reaching effects of circadian rhythms, Peeples discusses research showing that premature infants “who get daily cycles of light and dark” in the neonatal intensive care unit gain weight faster than those “kept under near constant light or dark,” and that an athlete’s performance has been found to “vary by 26 percent over the course of the day” due to circadian fluctuations in energy levels. Peeples enlivens the research discussions with original reporting, recounting the discombobulation she felt after spending 10 days in an underground bunker with no awareness of the time, as well as her sleepless nights camping out in Denali, Alaska, where the summer sun never sets. Peeples includes a few tips on practicing “circadian hygiene” (avoid screens at night and restrict food intake to late morning and early afternoon), but the focus is largely on the stimulating research showing how circadian rhythms rule people’s lives. This enlightens. Agent: Suzanne Gluck, WME. (Sept.)