bed & wake times linked to body fat
The link between sleep and health is not exactly earth-shattering news. Plenty of recent research has proven that skimping on sleep is bad for your waistline, not to mention that it's hard on that zen earth-mother thing you're going for, isn't it, cranky? Now research from Brigham Young University might put even more of a cramp on your night owl ways. It seems WHEN you sleep contributes to how lean you are.
As any parent knows, there is a period of at least 6-12 months after a baby is born where a solid night's sleep seems like some mythological event you'll hear about over and over again but never truly relate to. Somewhere, people are riding unicorns and clocking a solid 8 hours under starry skies. Not you. When those days pass (I promise, they pass), resist the temptation to return to your pre-kid late night TV binges and Saturday morning sleep-ins. Here's why...
BYU professor Bruce Bailey studied over 300 women (aged 17-26) over several weeks and found the best sleepers had the healthiest weights. Here are some of the highlights of his findings:
a consistent bedtime related to lower body fat
even more than bedtime, a consistent waking time related to lower body fat
sleeping less than 6.5 or more than 8.5 hours per night is related to higher body fat
quality of sleep overall is related to body composition
What does a "consistent" bed time and wake time really mean? Do you have to set the alarm, even on a Saturday? The bottom line is more than 90 minutes of variation --> higher body fat. So varying between a 10-11 p.m. bedtime is fine over the course of the week. Staying up some nights until 1 a.m. to catch up with your PVR and crashing other nights at 9:30 p.m. because you're sacked is a great way to gain some weight. Worse, getting up at 5:30 a.m. for the gym 3 days per week, 7:30 a.m. the other 2 work days, then sleeping in until 9 a.m. while your hubby takes the first kiddo shift on the weekend could be a recipe for a muffin top... yummy...
And when you can sleep through the night without nursing, diaper changing, chasing away monsters and changing urine-soaked sheets (theirs, not yours, I hope), the sweet spot for leanness seems to be 8-8.5 hours of sleep per night. Those in the study who slept 8-8.5 hours had the lowest body fat.
So, if you are up for the gym at 5:30 some days, shoot for a 6:00 wake up the other days and enjoy the extra half hour. Earlywake times lead to sleepiness earlier in the evening, which means you'll feel ready for bed sooner and nod off more quickly -- making a 10 p.m. - 6 a.m. sleep period possible, and possibly, your tummy just a little bit flatter.
To improve sleep quality, Bailey recommends the following:
keep the bedroom cool
sleep in a quiet room
sleep in a dark room, with windows blacked out and LED lights off/blocked
use beds only for sleeping (well, and for creating more children who will rob you of sleep yet again, of course.)
"Sleep is often a casualty of trying to do more and be better and it is often sacrificed, especially by college students, who kind of wear it as a badge of honor," Bailey said.
College students? I think maybe Bailey doesn't know any mothers.