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Daylight Saving 2011: How Time Change Affects Our Health

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DAYLIGHT SAVINGS TIME
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At 2 a.m. Sunday morning, we finally recaptured that lost hour of sleep from last March as we marked the end of daylight saving time. And for the 47 million Americans who are sleep deprived, that extra hour is a chance to literally make up for lost time.

"This is one of those weekends we should really relish," said HuffPost blogger Russell Rosenberg, Ph.D., CEO of the Atlanta School of Sleep Medicine and chairman of the board of the National Sleep Foundation. "The fact that Americans are so sleep deprived, it's a nice reprieve from the busy lifestyles that we all lead."

Rosenberg said this is the "good news story" of daylight saving time -- the welcome counterpart to the hour of sleep we lose at the beginning of spring, which can take up to a week to adjust to and send those who are already sleep deprived over the threshold of "crashing and burning." In fact, some studies have found a link between the spring-forward clock change and an increase in accidents and heart attacks.

On the other hand, some of those same studies often suggest the opposite effect in the fall -- a New England Journal of Medicine report found that heart attack rates decrease the Monday after the end of daylight saving time, Harvard Health Blog reports, while a Canadian study found a decrease in car accidents after the fall change, though Harvard Health Blog does point out that another study found an increase in accidents after both changes.

These time changes play out in our body a bit like jet lag might, explained Michael Decker, Ph.D., an associate professor at Georgia State University and spokesman for the American Academy of Sleep Medicine. Springing forward is like flying from west to east -- say from California to Washington, D.C. -- while falling back is like flying from east to west. And as frequent flyers can attest, the eastbound change is much harder to acclimate to than the westbound for most. "The adjustment is much milder in the fall than it is in the springtime," Decker says. And that means we may be experiencing a collective, but mild, jet lag this Sunday, which will clear up in 24 hours or so.

Yet while the transition may be an easy one, for many falling back also signifies a shift into winter and the changing light patterns that come with it. And perhaps that's the real health story behind the end of daylight saving time, stretching into winter long after that regained hour is forgotten.

For early birds and school children, the shift will mean it's light instead of dark outside in the mornings, which is good news for our internal biological clocks. When light stimulates a certain part of the brain first thing in the morning, it can make us more vigilant throughout the day and boost moods in the long run, Decker explained. "Now that the sun is rising a little earlier, we really want to think about getting up, going outside," he said. "Getting that bright light in the morning is absolutely key to health and performance and everything that goes with it."

But getting sunlight earlier in the day also means it may already be dark by the time people are leaving work. "There's always a psychological impact of it getting dark so early -- feeling that the days are shorter, and that winter is coming," Rosenberg explained.

And over time, that increase in darkness can lead to feeling blue and even experiencing Seasonal Affective Disorder. According to the NIH, symptoms of SAD typically start in late autumn and winter and include increased appetite, increased daytime sleepiness, decreased energy in the afternoon, loss of interest in work, unhappiness and lethargy. If you're experiencing symptoms of SAD, speak to your doctor, who may start you on bright light therapy, Decker said. This technology emulates natural sunlight -- sorry, the fluorescent office lighting won't do the trick -- in order to re-sync your biological clock and sleep cycle. Check out more information on Seasonal Affective Disorder from HuffPost Mental Health Editor Lloyd Sederer, M.D., here.

Amidst the hype over daylight saving time, though, experts are also taking the opportunity to remind sleep-deprived Americans of the importance of good sleep hygiene and habits year-round.

While we may fret about gaining or losing that hour twice a year, Frisca L. Yan-Go, M.D., medical director of the UCLA Sleep Disorders Center and Laboratory, points out that abruptly staying out until 2 a.m. and sleeping until noon on the weekends can shift your body clock two and a half time zones every single weekend, which is far more significant than the one hour change that happens twice a year.

She tells her patients not to shift their sleep schedules more than two hours from weekday to weekend and to be mindful of maintaining regular sleep with a brief daytime power nap, if necessary. Studies have linked chronic sleep deprivation, beyond the situational daylight saving time changes, to increased traffic accidents and heart attacks, as well.

Rosenberg echoes that sentiment, pointing out that the end of daylight saving time kicks off with a much needed extra hour right before the busy holiday season, which is often marked by increased sleep debt and alcohol consumption, which can ruin sleep cycles in its own right. "This is a good weekend," he said, "to catch up on your sleep and start off the holiday season getting good sleep and more regular hours."

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Having trouble sleeping beyond daylight saving time? Check out this related Huffington Post slideshow on five everyday things keeping you from getting good sleep.

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