The Tribune

By Bettyjoe Cooper

Staying up and waking up an extra hour or two later on the weekend can wreak havoc on your sleep and mood. It's known as 'social jet lag' and researchers now believe it can impact your health.

The results of the research show that for each hour of social jet lag, there is an 11 per cent increase in the likelihood of heart disease. The findings are independent of sleep duration and insomnia, which are related to both social jet lag and health.

Dr Michael A Grandner, director of the Sleep and Health Research Programme, led the research team. They researched data from the community-based Sleep and Healthy Activity, Diet, Environment, and Socialisation (SHADES) study. Survey responses came from 984 adults between 22 and 60 years old.

"These results indicate that sleep regularity, beyond sleep duration alone, plays a significant role in our health," said lead author Sierra B Forbush, an undergraduate research assistant in the Sleep and Health Research Programme at the University of Arizona in Tucson. "This suggests that a regular sleep schedule may be an effective, relatively simple, and inexpensive preventative treatment for heart disease as well as many other health problems."

According to Shelby Freedman Harris, director of Behavioural Sleep Medicine at Montefiore Medical Centre in New York City, social jet lag is becoming more widespread. "It isn't necessarily a sleep disorder that we would actually diagnose someone with clinically, but it is a trend where we notice that people aren't sticking with the same sleep-wake schedule every day," Ms Harris explains.

Those late Friday and Saturday nights and long weekend sleep-ins can disrupt our body clocks. It can explain why we often feel grumpy on Monday mornings since our bodies have trouble adjusting to our 'regular' sleep time.

"All of this happens because we're messing with our circadian rhythm -- that internal body clock that governs our sleep/wake times, as well as our appetite. Think of staying up past your usual bedtime as having a similar effect on your body as jet lag after travelling. You're putting your body into a different time zone when you sleep late on Saturday and Sunday," she said.

Come Sunday night, your internal clock has a tougher time readjusting to your normal weekday schedule. Then along comes that Sunday night insomnia. "You eat on a different schedule on the weekends, exercise differently and get light exposure later -- all of this delays the circadian rhythm," said Ms Harris.

Here are some tips to overcome social jet lag so you don't have the Monday morning blues:

• Sleep well

Try to avoid having a sleep debt to make up by the weekend. Get a solid night's sleep during each of the weeknights.

• Nap

If you are planning a late night, take naps of no longer than 20 minutes before 2pm, the day before and after. This will ensure that your sleep routine is not messed with.

• Don't sleep in on the weekends

Yes, this will be hard. According to Ms Harris, sleeping late on both Saturday and Sunday after both late nights is a no-no. Doing so can make adjusting to your regular sleep schedule more difficult come Sunday evening.

• Move

Force yourself to do some exercise, at the gym or even a walk shortly after waking up. You'll be less tempted to jump back in bed after breakfast.

• Get some daylight

Open the curtains and get some sun first thing. Enjoy breakfast by a window and then go outside. "Light helps to keep your circadian rhythm in check and it helps diminish melatonin levels -- a hormone that makes you sleepy and comes out in darkness," explains Ms Harris.

• Limit drink nights

According to Ms Harris, you're better off drinking alcohol one night over the weekend, rather than both. Excessive booze can worsen the quality of sleep, worsening the social jet lag effect of sleeping in.

• No coffee after 2pm

We know coffee contains caffeine which can kick-start our day. And it's good for you. But avoid it after 2pm otherwise you risk it interfering with your sleep that night.

In conclusion: Catching an extra hour or two of rest on the weekends isn't the worst thing ever. And nobody is suggesting you don't have a social life. "But if you are someone who has sleep problems on Sunday nights or during the workweek, keeping a more consistent wake time is really key," advises Ms Harris. "The bedtime is important, but waking up at the same time is even more important."

• Bettyjoe Cooper is an author and founder of Brand New Mattress Company in Nassau. For more useful information and sleep tips, check out her blog at www.brandnewmattress.com.