Stores used to open at 6 a.m. on the Friday morning after Thanksgiving. Sure, you spent all night in a tent outside, but at least you caught SOME shut eye. Now the big chains like Target, Kohl's and Best Buy are opening at midnight. That’s six extra hours of sales time. What’s a dedicated shopper to do but stay up all night?

An estimated 152 million people are expected to shop over Black Friday weekend, according to the National Retail Federation. That’s 152 million people who could be feeling just a little bit exhausted, not to mention the thousands of employees who are working this weekend, including those on overnight shifts.

Anytime you mess with your body’s natural circadian rhythm there are going to be consequences. First to go is your mood, says CNN sleep expert Lisa Shives. You’ll be irritable and impatient, making the mall a perfect storm of stress. Next to go is your metabolism – so stay away from the food court.



“Many of the hormones that regulate how we metabolize nutrients, they have a 24-hour rhythm,” Shives says, “So they’re not working optimally if you’re eating in the middle of the night.”

Third to decline is your cognitive function. Driving is never a good idea while sleep deprived, so try to have someone who’s had a good night’s rest pick you up from the mall.

Your decision-making ability and your impulse control will also decline, Shives says, which plays nicely into retailers’ hands. You’re more likely to make large purchases unnecessarily when your brain is half asleep.

Finally, getting back on track is going to be a bit of struggle for shop-til-you-droppers.

“You’ll likely come home after shopping and sleep most of the day. Then they’re going to have trouble sleeping that night. If they have to get up and go to work [Monday], they’ll have one very bad day.”

Here are some tips to help you recuperate from your shopping expedition faster:

Avoid taking your children. Children have a harder time re-adjusting to a sleep schedule, Shives says. Leaving them at home will keep them on track.

Take a 20 minute nap. When you get home on Friday, don’t fall asleep for hours. Studies show that a 20 minute nap will leave you feeling more refreshed than a longer siesta.

Go to bed at a normal hour. After your nap, stay up as long a possible on Friday, Shives suggests. If you fall asleep too early you might wake up at 2 or 3 a.m., raring to head back to the mall.

Wake up at a normal hour. We know it’s the holidays, but don’t sleep in too late on Saturday or Sunday morning. Otherwise you’ll have quite the shock come Monday.

Happy Black Friday shopping!