Strategies can make adjustment to daylight saving time easier, mitigate health impacts
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Daylight saving time has been a source of contention and debate since its introduction in 1918.
For some, the practice of advancing clocks to allow for more use of daylight hours in the summer — which a congressional act standardized across the country in 1966 — creates a general sense of disruption and confusion.
It also has been associated with increased incidence of stroke, heart attacks, atrial fibrillation and other health problems, particularly among individuals aged older than 65 years. Data also suggest an increase in fatal car accidents following the end of daylight saving time (DST), when Americans “spring forward” and lose an hour of sleep.
Several state legislatures and federal lawmakers have considered legislation in recent years that would eliminate changing clocks to standard time between November and March, establishing DST year-round.
Until change is enacted, individuals can take steps to prepare for the annual transitions into and out of DST to mitigate its negative effects, according to Krista Kezbers, PhD, ACSM-EIM, ACSM-CPT, DipACLM, research professional/senior program manager of the Health Promotion Research Center within Stephenson Cancer Center at University of Oklahoma Health Sciences.
Kezbers gave a talk on the topic at this year’s American College of Lifestyle Medicine annual conference.
“This happens twice a year, but it still sneaks up on us every single time,” Kezbers told Healio. “We’re exploring policy change in the future, but just knowing what to expect and taking steps to ease the transition can be very helpful to people who struggle with this.”
A reasonable tradeoff?
In her talk — titled “Let There Be Light — But in the Morning or Night?” — Kezbers discussed the original goal of DST, which was to conserve energy and optimize the use of daylight hours.
Given the innovations in lighting and the increased use of electronic devices over time, the benefit of DST with regard to energy conservation is minimal, she said.
“Most of the studies that have been done in relation to energy consumption around DST show a 1% savings, which is a small benefit,” Kezbers said. “We’re not seeing these huge benefits that they saw during World War I, when this was implemented and was really needed for survival.”
This small benefit is countered by many potential health consequences of DST, Kezbers said. She discussed the effects of DST on health in relation to the pillars of lifestyle medicine — sleep, physical activity, nutrition, social connection, avoidance of risky substances and stress management.
“The most obvious one is sleep. You spring forward [and] technically lose an hour’s sleep, and that’s a nuanced thing,” she said. “People with good sleep habits try to sleep at around the same time but, with DST, their work lives or social lives shift by an hour. These people have an increase in fatigue and sleepiness, and decreased alertness.”
She discussed ecological momentary assessment (EMA) studies that track health behaviors during DST transitions. EMAs use self-reports to assess behavior patterns in real-time in a subject’s environment.
“EMAs are a quick snapshot of how someone is feeling and how they’re doing,” Kezbers said. “The person taking the assessment reports on whether they feel happy, sad or tired. [EMAs] also capture health behaviors like exercise or consuming sugar-sweetened beverages.”
One EMA study evaluated the behavior of smokers around DST. Results showed smokers’ motivation to quit decreased during this time, Kezbers said.
She also mentioned a study called EXEMPLAR, which enrolled 93 people during DST in spring 2022.
“We found things like decreased happiness, increased tiredness and enhanced feelings of pain, which was an odd finding,” she said. “They also had increases in fear, but there was no difference in physical activity — that was one that remained fairly consistent.”
Three schools of thought
The debate surrounding DST has prompted discussions about how to move forward on this matter in the modern world, Kezbers said.
These conversations focus largely on three potential strategies: eliminating DST in favor of permanent standard time; continuing to observe the established time changes in spring and fall; or switching to permanent DST.
In 2022, the Senate passed the Sunshine Protection Act, which called for the nation to switch to DST in the spring and not change back to standard time in the fall.
“We would get a little bit of a difference in terms of winter light — we would have light longer in the evening, and it wouldn’t be dark at [5 p.m.],” Kezbers said. “The tradeoff to that is that sunrise wouldn’t happen until 8 to 8:30 a.m. for some locations. We’d be sending ourselves to school and work in the dark.”
Kezbers said she favors the opposite solution — a switch to permanent standard time.
“We would be sacrificing a little bit of evening light from March to November, but we’d be doing that in order to get the morning light and keep us in line with where the sun is,” she said. “I believe the data supports this, and there have been organizations that have come out with position statements saying this. I do think we would gain some health benefits.”
Easing the transition
Although many researchers are exploring ways to address the issue of DST on a policy level, individuals can find ways to make the transition easier in the short term, Kezbers said.
Consistency of sleep pattern is the best approach, she said.
“A lot of times with the ‘fall back,’ people look forward to the extra hour they are gaining — especially people who are enjoying nightlife and social culture,” she said. “In reality, though, people end up sleeping less during that time. My biggest recommendation is to try to keep your sleep duration the same in the week leading up to DST. That should help make the adjustment a little bit easier.”
It is important to get morning sunlight exposure on the Sunday after DST transitions to help the body adjust to the time change, Kezbers said.
Kezbers also recommended continuing to sleep the same number of hours but adjusting bedtime incrementally during the week leading up to DST. For example, a person whose normal bedtime is 9:30 p.m. might go to bed at 9:25 p.m. one night, 9:20 p.m. the next night, and 9:15 p.m. the following night.
“Your body will adjust better to that than it would to going from 9:30 to 8:30,” she said.
Getting exposure to morning sunlight also helps, Kezbers said, because it helps the body adjust to what is naturally occurring outside.
For individuals who struggle with the adjustment, Kezbers advised lightening up one’s commitments on the Sunday and Monday after the time change.
“Lessen your meetings if you know you’re going to be less alert, less attentive or more stressed,” she said. “Take that off your plate if you can. That way, it’s a bit more relaxed of a day and you can get through it better.”
Reference:
- Kezbers, K. Let there be light — but in the morning or at night? The influence of daylight saving time on health behaviors. Presented at Lifestyle Medicine Conference; Oct. 27-30, 2024; Orlando.
For more information:
Krista Kezbers, PhD, ACSM-EIM, ACSM-CPT, DipACLM, can be reached at krista-kezbers@ouhsc.edu.
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