After seemingly hours of rocking, bouncing, and nursing, your sweet sleep-fighting baby has finally gone down for her nap.
Now it’s decision time: Will you use your precious time to squeeze in a quick workout, or to lie down and try to catch up on some much-needed rest yourself?
This is a common quandary for sleep-deprived new moms. We’re naturally anxious to start dropping our postpartum pounds. But we are also soooo damn tired.
“Tough-it-out” messages about sleep deprivation and “just do it” messages about getting back our pre-baby bodies suggest that the quick workout is the way to go. They tell us to suck it up, tough it out, don’t worry about the spit up on your shirt or the fact that you haven’t washed your hair in days, it’s time to hit the gym, mama!
Here’s the problem with those guilt-inducing cultural messages: Ceding to our body’s message that it desperately needs more rest is not lazy. It is wise. And ironically, trying to tough out a lack of sleep to exercise can have the opposite effect–making it harder to shed your baby weight.
Ceding to our body’s message that it desperately needs more rest is not lazy.
It is wise.
The research on this point is clear: The more we shortchange ourselves on sleep, the more sleep debt we accumulate. And the more sleep debt we carry, the harder it is to lose weight.
Think of sleep as part of your postpartum weight loss regiment, because:
Lack of sleep lowers your energy levels.
When you push yourself to workout despite being tired, you’re likely to expend less energy in subtle ways throughout the rest of the day, by sitting more, walking more slowly, and so on. All these little things lower your overall calorie burn and can easily negate any of the extra calories you burned during a brief bout of exercise.
Dieting while tired causes you to mainly lose muscle, not fat.
In one study, researchers put a group of overweight men and women on a strict low-calorie diet. For two weeks they were maintained on this diet while under close observation at a medical center. Half of the group was allowed allowed only five and a half hours in bed (the low-sleep group); the others half was allowed eight and a half hours in bed (the high-sleep group).
In the low-sleep group, over 70% of The weight lost came from muscle.
Both groups lost weight, but in the low-sleep group, over 70% of that weight loss came from muscle. In contrast, in the high-sleep group, over 50% of the weight loss came from losing fat.
Lack of sleep makes you hungry
Lack of sleep mucks with the appetite-regulating hormones leptin and ghrelin. Compared with getting a full night of 8 to 9 hours, even just a few nights of short sleep, only 4 to 5 hours, causes a precipitous drop in how your brain responds to leptin (a satiety, “I’m full” hormone) and a simultaneous rise in ghrelin (a hunger “How about some more cookies” hormone). These hormonal changes make you feel hungry, even when you are taking in enough calories to sustain your weight.
Lack of sleep mucks with your appetite-regulating hormones
One study showed that after just a couple of nights of short sleep, people not felt hungrier, but also ate an average of 300 additional calories a day–an amount which, if maintained, translates to an extra 10 to 15 pounds of weight gain in a year.
Those are not the only harmful hormonal effects of a lack of sleep: It also causes you to become more resistant to insulin and to gain weight around your middle, increasing your risk of type 2 diabetes.
Lack of sleep makes your brain crave junk food.
Yep, you’re not imagining it, that normally unappealing day old cookie at your favorite coffee shop is suddenly calling to you.
People forced to sleep only 4 to 5 hours a night (as opposed being allowed to sleep 8 to 9 hours) not only take in extra calories without feeling more full, they preferentially get those calories from sugary, salty, high-carbohydrate “junk” food—-cookies, cake, pastries, crackers, and potato chips.
Sleep deprivation basically gives you the munchies.
Brain research using MRI shows that after sleep deprivation, areas of the brain involved in reward and addiction have enhanced reactions to these low quality, high reward foods. At the same time, areas of the brain involved in judgements and behavior control become less active, making it harder to quiet the impulse to down the whole pint of ice cream. It’s a neurological recipe for binge eating.
And yep, its gets worse: Lack of sleep also boosts a group of neurotransmitters in the brain known as endocannabinoids–whose actions are mimicked by marijuana (cannabis), hence their name (meaning endogenous, i.e., internal, cannabinoids). To translate: Sleep deprivation basically gives you the munchies.
What you can do
For new parents, and moms in particular, mountains of sleep debt are just the norm. Babies do not keep regular hours. They wake up in the middle of the night, demanding to be held, or fed, or bounced.
But we do not need to make our chronic lack of sleep worse by pretending we can just tough it out. Or by feeling lazy if we take a nap or ask our partner to take our baby first thing in the morning so we can sleep in. Or by feeling lazy for not hitting the gym or doing aerobics videos in our sole ten minutes of down time.
So let the guilt go. Paying down your inevitable sleep debt is the the right choice for your mental and physical health and your weight loss goals!