Instead of Gaining an Hour of Sleep, You May Get a Week’s Worth of Woes
For the chronically sleep-deprived—50 to 70 million Americans, according to studies — the first morning of the return to standard time, the morning when clocks “fall back,” feels like a godsend. An entire extra hour to sleep with not a second lost in time! It’s almost too good to be true.
In fact, it is. The benefit of an extra hour of sleep gained on the clock’s return to Standard Time is more than negated by the effects on the body of the change in the relationship of the clock to the hours of daylight and darkness. The effects can disrupt the body’s sleep cycle for days, according to experts.
“A minority of people actually sleep an extra hour,” says George Neal, MD, director of the New England Sleep Center at Catholic Medical Center. “For most people, it’s just another hour of being awake. It’s easier to adjust to staying up later than it is to going to sleep an hour earlier.”
Daylight Saving Time, with its twice-yearly clock adjustment, is in effect in 70 countries around the world and in 48 of the 50 U.S. states (Arizona and Hawaii do not observe DST). According to a 2013 literature review conducted by Dr. Yvonne Harrison of Liverpool John Moores University in the United Kingdom and published in the journal Sleep Medicine Reviews, “Relative ease in adjustment of sleep patterns is assumed by the general population, but this review suggest that the scientific data challenge a popular understanding of the clock change periods.” The review found little evidence that people actually gain an extra hour of sleep when clocks change in the fall from DST to Standard time. Moreover, “the cumulative effect of five consecutive days of earlier rise times following the autumn change again suggests a net loss of sleep across the week.”
According to Dr. Neal, the brain operates on a 24-hour schedule of sleep and wakefulness, what’s called the circadian rhythm. “The sleep-wake cycle has a rhythm but it’s plastic and can adjust. It’s sensitive to light. The exposure of light to the eyes connects to certain pathways in the brain, which controls and adjusts to the cycle.”
He concurs with studies showing that it takes about a week to adjust fully to a time change, and notes that the people who will have the most trouble adjusting are “those who are sleep-deprived and those who tend to get up early.” Older people can also have trouble adjusting, he adds, because their sleep cycle tends to be less adaptable.
Disrupted sleep patterns can cause mood swings, drowsiness on the job, loss of focus, difficulty in concentrating, and disturbed hunger-appetite patterns. The problem can be especially dangerous for operators of heavy equipment, but everyday driving can be impacted as well. Evidence shows the rate of traffic accidents upticks at both ends of DST, when clocks “spring forward” in March and then fall back again in November.
Dr. Neal advises people to maintain their regular patterns of eating, exercise, and sleep, all of which contribute to a normal, regular circadian rhythm. Remember that adjusting to a new clock time will take a few days for the body, which operates on a 24-hour schedule and is affected by light.