Sleep and Weight Loss

adamsr6
adamsr6 Posts: 1 Member
in Sleep, Mindfulness and Overall Wellness
Hi!

Has anyone else remember hearing "your body is still working while you sleep" after late night exercising?

Well, last night I went vigorous for 30 minutes with a combination of elliptical and stationary bike riding.

I got up around 4 am getting my hubby off to work. I weighed myself and the scale showed a loss of 2 pounds. I laid back down and woke up around 9am. I weighed myself again and had lost another pound.

Of course, I am trying to figure out why another pound. My only conclusion was because during my first sleep journey I did not sleep very well, constantly waking up. The second time, I slept like a baby.

What are your thoughts or experience?

Replies

  • AnnPT77
    AnnPT77 Posts: 34,216 Member
    It's primarily water weight. While 80% of the fat we burn leaves the body via exhaled gasses (the rest as water), fat changes just aren't that speedy.

    Whether you exercise late or don't, your body is always working while you're asleep. Just being alive burns calories, awake or asleep. While sleep burns very few calories per hour (because not much is happening, right?), most of those calories do come from stored body fat.

    After exercise, you do burn a few more calories for a while after you stop. It's called excess post-exercise oxygen consumpion, a.k.a. EPOC. Some people call it afterburn. Sure, if you go to sleep right after you exercise, that EPOC can happen during sleep. If you don't go to sleep right after exercise, it happens while you're doing . . . whatever. It's a small number of calories, estimated to top out - at an extreme - at maybe 7%-15% of the calories burned during the exercise itself. Being asleep doesn't magically multiply EPOC.

    Your fat loss comes from your all-day(s) average calorie deficit. You burn calories you all day(s) long, from being alive, plus daily life stuff like job and home chores, plus exercise. When that's more calories than you eat, you'll lose weight, and most of the weight will be body fat. It doesn't really matter when that stored fat burns - asleep, awake, exercising, watching TV, whatever - if there's a calorie deficit, it's going to be made up from stored body fat sooner or later.

    Multi-pound changes from one day to the next are mostly about fluctuations in digestive contents and fluctuations in water retention.

    Most of the weight of your food becomes waste - an apple only has maybe enough calories to account for 0.03 of a pound (0.014 of a kg), but it weighs as much in your stomach as it did in your hand (maybe up to half a pound for a big'un).

    Changes in water retention are the biggie, though. Our bodies can be up to 60%+ water, and holding/releasing pounds of it are part of how a healthy body remains healthy. Don't mistake that for fat gain/loss - that's super stressful as well as inaccurate.

    Generally, people will see a scale loss overnight. Why? There's no intake while asleep, food or fluid. Some fat is burned and the waste gasses exhaled (like I said, fat is the main fuel during sleep - tiny amounts). More importantly, while we sleep, we sweat, plus we exhale moisture (water) as well as the other gasses. It's mainly that water loss that shows up on the scale after sleep. If you urinated after you got up at 4AM, that's another water loss.

    The late exercise possibly contributed to your poor sleep early in the night: That's not a universal thing, but it's common. Loosely, the exercise gets the body hopping, and it takes time for it to settle into restfulness.

    Don't read anything meaningful about body fat loss into quick scale changes. In a healthy body, fat loss is gradual, a few ounces/grams a day, even when losing weight fast. Two pounds a week of fat loss is less than 5 ounces per day. (A kg of loss per week is around 142g daily.) The fat loss will show up in the scale-weight trend as averaged over multiple weeks. Observable muscle gain/loss is even slower, a thing of many weeks to some months.

    Reading deep meaning into trends over a number of hours - unless there's a health crisis in play - is just going to be stressful and misleading.

    I'd strongly recommend reading this article, if you haven't:

    http://physiqonomics.com/the-weird-and-highly-annoying-world-of-scale-weight-and-fluctuations/

    Other MFP-ers talk about their experiences here:

    https://community.myfitnesspal.com/en/discussion/10683010/the-weird-and-highly-annoying-world-of-scale-fluctuations/p1

    Best wishes!

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