1500 and 1950 is not a calorie count i'm familiar in EMWL

i dont know your height. in the calculator i put your stats at 166 36 yrs... i put you at 5'5 with 5/6 hours a week of strenuous exercise - at 15% reduction . you're looking at 2210 cals.

This has nothing to do with your body is used to exercise - that improves your aerobic capacity, not ability or how much energy it takes or what not. That is a huge fad phrase that is going around propagated by infomercials.

The only time you might say a body can get used to exercise, is think of something like walking (leaving out race walking format to take it up a notch).

At some point you can only walk so fast. If the same weight you burn the same calories. You put the same loads on the muscles.

But obviously at some point you aren't going to improve - but you won't lose fitness either. So basically it's no longer stressful.

So think of your classes - either teaching or taking. Which ones are like that - your move to the beat of the music, and use no or same weights as always, so no extra load.
Those workouts are not making improvements anymore. Maybe aerobic just a tad, but much slower than at start because probably not a load on muscles anymore.

Those are the types of workouts that if you lost weight doing it - now you have lost fitness - because it was a heavier load on body when you weighed more. Just like losing weight walking, you will lose fitness if you don't increase the load.

Like squatting or deadlift.
If you got up to say 200 lbs, then lost 20 lbs bodyweight, and increased bar weight to 220 - you didn't improve - you maintained.
If you stayed at 200 - you lost muscle strength and likely muscle actually.

I'd suggest if you now have chance to do your own workouts - make them activity recovery - the last thing you need is HIIT, which is stressful as lifting if you can do it right, and needs recovery - which I doubt you can give your body with that schedule.

You can easily gain upwards of 20 lbs water weight from increased cortisol.

You could likely recover while keeping the minimum workout schedule you could merely for reducing stress - but it would mean getting your mind off the scale and on the measurements and performance.
Because you would gain water weight during recovery, but that would be good water weight, and many find they drop the stress water weight at same time or in whooshes.

So be very specific in your mind about facts.

You can't gain fat fast, or lose fast for that matter - only water weight.

Of course you lose after doing exercise - I can lose 10 lbs on a long bike ride despite drinking 7 lbs of water during the 3 hrs.
Do I even imagine that is real fat weight (well, out of 2700 calories, some is fat, some carbs, and some carb attached water released)?
Not a chance.

So you gotta have some correct views of what happens.

More later.

Spin class?
If you do it like I've seen the instructors teach it - it's nothing but intervals almost. Pretty high stress.

I had a 3 week period that I did the math on after the fact, and 3 days a week, with rest day between - but bigger deficit than I knew (using old VO2max calorie burn rate too low) - I lost 3 lbs of LBM, and since doing endurance cardio, I know majority wasn't merely carbs stored with attached water - it was muscle mass.
My carb intake wasn't enough to support the high carb burn classes like that. By the last day, I figured my carb stores were depleted enough I was basically causing a bonk situation almost, where there is low enough glucose in muscles your body must resort to muscle teardown to supply more blood sugar to burn.

Though the master spin instructor in this whole city is at this gym and has all the other instructors start up base training here in a couple weeks.

Anyway, just your stats at the likely Lightly Active you are with merely your kids and increased daily activity from that, and that's all - I show a TDEE around 2000.

No exercise even account for yet.

So for sure you need to be eating at 2000 - and going up.
Your potential deficit must be big, and I'd bet around 20% of potential TDEE.

To unstress the body - Skip the HIIT if doing real weight lifting.

I'm betting the only reason for doing it is not because of some thrill with doing it - but because you know it can be a great fat burner.
But that's compared to doing the workout steady-state aerobic for equal time.
And HIIT is as close to lifting as you can get for those that don't want to lift.
But you do. So in that case it's just a big stress on your body likely. If not interfering with having a good lifting workout, and probably from repairing from a good one if you even can get one.

I'd suggest if you just love the feeling of intervals say running, do 10-15 min worth at the end of lifting where legs are included if you really have the time - that way the next day is recovery for lifting and intervals.

If you can arrange your schedule to have the next 24-36 hrs NOT be another massive load on the same muscles as you just lifted with - then you can have a good recovery actually.
If you are wasting the recovery - don't even waste time on the lifting - you aren't getting out of it what you could, except extra stress on the body.

For instance, if I missed a Thu leg day for some reason but had a chance to do it on Fri - I'd skip it if Sat was going to be big hard bike ride day, and Sun could not be that day. No use even wasting the effort to tear the body down to require building it up stronger - if I'm going to prevent that repair from being done with next day's workout.

So that's scary your body has been suppressed so low, that basically all your workouts don't account for any extra calorie burn compared to a Lightly Active day for average metabolism.

You should eat 250 more for 2 weeks.

If you feel it's believable that your real potential TDEE is around 1950 because that's where you eat with no weight change - than 250 more daily for 2 weeks should only cause a slow 1 lb weight gain.

And with lifting - won't even fat.

But I'm betting your glucose starving muscles are going to top off, and your metabolism will therefore speed right up, and your workouts will reach a level you haven't felt before if all other factors stay the same, meaning you burn more daily that way too.

Isn't increased appetite a good thing? A sign your metabolism is recovering?

Hey there I think you need to be practical and trust in other people for a bit ...Haybales, myself etc we are all banging on the same drum... 2000 cals should be the total minimum food you should be consuming. And I agree with haybales I higher number is more realistic... I personally think 2500 per day every day is a much more realistic number concidering your activity levels.

Your weight will shoot up temporarily because your body has been starved for so long its going to do all sorts of crazy things, but once your metabolism re-sets you can look at setting a realistic deficit.

it's the only way to fix your current predicament im afraid. in many ways your body is reacting in the same way someone with an eating disorders would. You are giving it food, but not enough for your activity level.

keeping this post for reference- super interesting. Thank you heybales!

Perhaps they picked better parents?

Oh wait .......

Can't pick our genetics, only our nose. Pretty sure that's not how the phrase goes, but I can't recall the other one.

So before did you slowly increase to 2200-2500 by 100-200 extra daily each week, or jumped straight up?

And from what prior eating level did you do so?

And did activity level increase, stay the same, or decrease?

You can gain 20 lbs of stress related water weight easily, perhaps more. That can mask a lot of weeks of fat loss.
Think of that, if you truly could maintain 500 cal deficit losing 1 lb weekly, for _20_ weeks you would not show it on the scale.
You are increasing weight though not trading, so easily could be body is stressed over potential deficit, slowed down enough, but stress out enough to still add the water weight.

That's why I am wondering if you are at a point you likely won't believe anything unless convinced by your own observation.

So if you think 1950 is your potential TDEE, and sounds like you might believe that, and actually right now, it is, I just think suppressed TDEE - you can test your theory very easily.

Eat 2200 for 2 weeks and see what happens. (pick a valid 2 weeks with no other expected water weight changes).

If you are correct - you will only gain 1 lb slowly. That's all you could gain eating 250 over maintenance for 2 weeks.

If I'm right - you'll gain more, or potentially none (if that's enough to lower stress). And you'll prove your daily burn is suppressed.

I suggest though you know what would happen, proving my point, not yours.

So increase calories by 100 daily for a week, or two.
Skip the HIIT, only do lifting, good strong compound full body 3 x weekly lifting. Unless you can't allow 24-36 hrs rest on those same muscles.
If you can't allow repair - you are just adding to the stress by lack of recovery. In which case only do lifting that allows that, perhaps upper body only 3 x weekly, lower body 1 x. Something like that. You could also do the lifting right before a class - the class doesn't know you might have the tension a tad lighter because you already did a hard workout.

Lack of sleep also adds to stress, confirm that is getting done.
Noticed what could be any food sensitivities? They can be worse on already stressed out body, and lowering those could be enough to help. They could be eaten again after body stress level is down.

Life - control what you can. A hard workout added on for stress relief may be decent for the mind, right then, but not likely for the body, nor the mind long term.

Since mental and emotional stress can cause physical changes to the structure of the brain (chemical balances), and even elevated blood pressure and the mechanisms behind that - sure they can.

The way I heard it described once that I liked the best, is that you can picture us all as having a genetic level to max stress and where it starts to have those effects.

So picture your your circus carnival high striker or strength tester with colored gauge going up, with red as last stretch of color.

All your stresses pile up, one on top of another, and push that gauge up the scale.
Lack of sleep and recovery from exercise (which can still happen even with enough sleep), food sensitivities or allergies can also hit harder when body is already under stress and cause more, daily life, disease or sick body, deficit eating, and others all add up.
When it hits the bell and your max stress level is passed, bad things happen.
What and how extreme and how long those things happen depend on how elevated you were already and how far over you went. Some people are at almost max level constantly, in the red, and constantly bump over you might say, so see some negatives of stress in their life constantly. Some are way below, hit a bump, bounce over, and right back down, not much bad happens even if bad at dealing with it.

I've known people that know they deal with stress terribly, so they plan their lives even better to limit as best they can any potential stresses. When they hit, it's bad, but it's brief and they are back down to normal.
And we all know people that seem to want to live a stressful chaotic life because that's what seems to surround them and their constant spur-the-moment decisions perpetuates it.

I really think that's why many will report in general forums that despite what I'd consider an extreme deficit, and not losing weight, they did something like eating all natural from a prior nutritionally poor diet. And they start to lose weight.
They dropped the level of stress just enough that the body didn't rebel against the extreme deficit as much. I'm sure it still did.

Or others will report just eating like 200 more calories daily for like 2 weeks and get a whoosh drop of weight, the lost the stress of the extreme deficit.

Constant unrecovered exercise can have same effect too. Since for vast majority of people the gauge of a workout being hard or not is totally subjective with no data, purely "feels hard" doesn't mean it still it compared to prior. So they take a week off (perhaps body got sick from suppressed immune system) exercise and actually drop some weight. Water weight.

So sometimes a careful examination of what you know to be stresses, and what could possibly be, and seeing is there anything you can control and lighten up on, can help.

But just as immune system can be suppressed, not operating at full potential, the rate your body burns calories can be suppressed too, not burning at full potential.
Sadly just like immune system - it's about impossible to compare at the time.
All you can do is compare after the fact. Really observe differences of response in the same situations.

I think biggest one that is easily seen and reported by many - they don't feel as cold when it's colder. Though you usually hear the inverse first - I'm so cold now. They usually blame it on losing fat, never mind it's wasn't that thick a layer everywhere and it's R-value isn't that great. Metabolism, ie heat produced from body processes - wasn't as high.

And you never know, the amount of stress you can take at new job could be totally influenced by the level of stress body is at already. If it was lower, might be able to take more without it feeling like it's more stress.