Large Calorie Deficit w/ Exercise
jtintx
Posts: 445 Member
This doesn't really fit neatly into a category but here goes. Let's say you eat 1500 calories a day. Normally that's enough to not put your body into "starvation mode." But let's say you also exercise a lot that evening and burn 1500 calories. And say you do that 3 times a week. I don't want to eat back those calories...for one thing I'm not hungry. But what will be the body's response to such a large caloric deficit even though you're eating a substantial amount of food? Glycogen stores will not be replaced with food that evening so what does the body do? Burn fat? Burn muscle? Can the body replace glycogen by burning excess body fat? I'm not sure if I'm hindering my weight loss (fat loss) by having days with very large calorie deficits. ???
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Replies
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First off, starvation mode as used here is not a thing.
Having too large a deficit consistently (this is the key here. you need to look at weekly averages) will cause your body to turn to muscle for fuel. Obly so much stored fat can be metabolised in a day, after that the body looks elsewhere.
I'd also be curious to know what you're doing to burn 1500 calories. It would take me more than 3 hours of strenuous cardio as a 165lb woman to burn even close to that much.15 -
There is a limit to how much fat your body can utilize for energy per day, so if you're regularly exceeding that with very large deficits, you'll be targeting your muscle for loss. If you're burning 4,500 calories a week through exercise and you aren't hungry, your hunger cues may not be a reliable guide to ensure you're eating enough. If you aren't hungry that night, how about eating some of them the next day?4
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Bad idea. Here's why.
Your body is using calories 24/7. Heart, lungs, kidneys etc. You have glycogen stores, you have fat stores.....but your body can't/won't use those energy sources exclusively. Only so much fat can be used everyday, glycogen is also being used for purposes other than exercise.
So the fuel your body has left is LEAN MUSCLE MASS. Without fueling your body appropriately you are essentially working out to burn (more) lean muscle mass.
So even though you "aren't hungry" your body is making choices......fuel heart muscle.....or fuel a full head of hair. The heart muscle wins and your hair starts falling out.
Hunger (or lack of) is not a good indicator of adequate nutrition. Eat a larger % of calorie dense foods (small portion sizes) and you can meet your calories.
Starvation mode myth - http://community.myfitnesspal.com/en/discussion/1077746/starvation-mode-adaptive-thermogenesis-and-weight-loss9 -
VintageFeline wrote: »First off, starvation mode as used here is not a thing.
Having too large a deficit consistently (this is the key here. you need to look at weekly averages) will cause your body to turn to muscle for fuel. Obly so much stored fat can be metabolised in a day, after that the body looks elsewhere.
I'd also be curious to know what you're doing to burn 1500 calories. It would take me more than 3 hours of strenuous cardio as a 165lb woman to burn even close to that much.
This was only an example but typically to burn that many calories I play 3 hours of competitive racquetball or go for bicycle rides over 50 miles.
How much stored fat can be metabolized in a day?0 -
It's a bad idea. I feel like I am posting this constantly but I will do it again.
Studies are showing that when energy availability decrease to a level below 20-30 calories per kg of lean mass (9.6-13.6 calories per lb), your system starts to adapt. Note that these adaptations begin within days of eating like this. It doesn't take weeks or months. One of the big adaptations is that your reproductive system senses that now is not a good time to reproduce and you lose your period. Estrogen levels also decrease to a level where bone regeneration is stunted, which can mean bone loss leading to increased risk of stress fractures and even osteoporosis.
Mathematic example:
Example woman:
140 lbs
27% bodyweight
102 lbs LBM
13.6 x 102 lbs = 1387 net calories would be tipping point
A few articles:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3435916/
http://www.bodyrecomposition.com/womens-physiology/body-fat-energy-availability-or-hormones-book-excerpt.html/
Video series from Brigham and Women's Hospital/Harvard Medical School: http://mdvideocenter.brighamandwomens.org/specialties/orthopedic-and-arthritis/female-athlete-triad-recognition-treatment-and-prevention/item/1
Starting around 23:00:
https://www.youtube.com/watch?v=rLcjhm4-CSg
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janejellyroll wrote: »There is a limit to how much fat your body can utilize for energy per day, so if you're regularly exceeding that with very large deficits, you'll be targeting your muscle for loss. If you're burning 4,500 calories a week through exercise and you aren't hungry, your hunger cues may not be a reliable guide to ensure you're eating enough. If you aren't hungry that night, how about eating some of them the next day?
I do eat the next day but breakfast and lunch only amount to about 800-1000 calories before my next workout.
Muscle loss is my concern. It seems that every time I gain and then have to lose weight I end up losing more and more muscle. I don't want to end up being "skinny-fat."0 -
Ummm...that's basically exercise bulimia. If you eat 1550 and burn 1500 with exercise you are providing zero energy (that's what a calorie is) for basic functions. If you're burning over 1500 calories on the regular, you are basically training like an athlete...you better learn to eat like one.
And yes...you will be destroying lean mass which includes your muscle mass...also, your heart is a muscle.23 -
The real tell will be how much weight you are losing per week. Starvation mode is not a thing in the short term - you would need to have a large deficit consistently over a long period of time, and all that would do is slow your metabolism, not stop you from losing weight.
If the info in your profile is correct, you have 35 lbs to go? You should be shooting for 1 lb per week. If you are consistently losing faster, you need to eat more. I think the healthy limit that is always mentioned is 1% of your body weight per week, but that would be the upper limit, fastest you should go. If you are prioritizing muscle-sparing, I think 1 lb would be the general advice.
Depending on how accurate your logging is, and how inflated your calorie burns are (both of which are likely, it happens all the time!), your deficit might not be as big as it seems.1 -
It's a bad idea. I feel like I am posting this constantly but I will do it again.
Studies are showing that when energy availability decrease to a level below 20-30 calories per kg of lean mass (9.6-13.6 calories per lb), your system starts to adapt. Note that these adaptations begin within days of eating like this. It doesn't take weeks or months. One of the big adaptations is that your reproductive system senses that now is not a good time to reproduce and you lose your period. Estrogen levels also decrease to a level where bone regeneration is stunted, which can mean bone loss leading to increased risk of stress fractures and even osteoporosis.
Mathematic example:
Example woman:
140 lbs
27% bodyweight
102 lbs LBM
13.6 x 102 lbs = 1387 net calories would be tipping point
I understand that but my question is that if I'm eating 1400-1700 calories a day does it matter that I have three days a week where exercise puts me at a huge calorie deficit? If just those three days are going to cause huge muscle loss then I would be willing to force myself to eat more. I am eating 20-30 calories per kg of lean mass, it's just that I have some really big calorie burn days.
An although I appreciate you taking the time to post links they are not relevant to me or my question. My question/concern is muscle loss.0 -
VintageFeline wrote: »First off, starvation mode as used here is not a thing.
Having too large a deficit consistently (this is the key here. you need to look at weekly averages) will cause your body to turn to muscle for fuel. Obly so much stored fat can be metabolised in a day, after that the body looks elsewhere.
I'd also be curious to know what you're doing to burn 1500 calories. It would take me more than 3 hours of strenuous cardio as a 165lb woman to burn even close to that much.
I only used "starvation mode" because I didn't want a bunch of responses about that.
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Why would you only want to eat 1500 calories a day if you are exercising to burn off the 1500 calories? This seems like an eating disorder which would leave you with muscle wasting and a host of other metabolic problems.6
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I'd say that if you can't physically eat to support your training then you need to reduce your training.19
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VintageFeline wrote: »First off, starvation mode as used here is not a thing.
Having too large a deficit consistently (this is the key here. you need to look at weekly averages) will cause your body to turn to muscle for fuel. Obly so much stored fat can be metabolised in a day, after that the body looks elsewhere.
I'd also be curious to know what you're doing to burn 1500 calories. It would take me more than 3 hours of strenuous cardio as a 165lb woman to burn even close to that much.
This was only an example but typically to burn that many calories I play 3 hours of competitive racquetball or go for bicycle rides over 50 miles.
How much stored fat can be metabolized in a day?
It doesn't matter because after a few days you would feel awful, binge and put a halt to your progress.
There are examples of people doing extreme amounts of activity with large calorie deficits for very short periods of time (2-4 days). Have a search for ERFL. This is not really the place to discuss such protocols though.0 -
janejellyroll wrote: »There is a limit to how much fat your body can utilize for energy per day, so if you're regularly exceeding that with very large deficits, you'll be targeting your muscle for loss. If you're burning 4,500 calories a week through exercise and you aren't hungry, your hunger cues may not be a reliable guide to ensure you're eating enough. If you aren't hungry that night, how about eating some of them the next day?
I do eat the next day but breakfast and lunch only amount to about 800-1000 calories before my next workout.
Muscle loss is my concern. It seems that every time I gain and then have to lose weight I end up losing more and more muscle. I don't want to end up being "skinny-fat."
Then you need to eat enough to ensure you aren't burning through your muscle. If you aren't hungry, try adding calorie-dense foods to your meals. Or, like @cwolfman13 suggested, look at ways to reduce your training.
If you're already noticing the impacts in your body composition, you know things aren't working the way you're trying to do them.2 -
It's a bad idea. I feel like I am posting this constantly but I will do it again.
Studies are showing that when energy availability decrease to a level below 20-30 calories per kg of lean mass (9.6-13.6 calories per lb), your system starts to adapt. Note that these adaptations begin within days of eating like this. It doesn't take weeks or months. One of the big adaptations is that your reproductive system senses that now is not a good time to reproduce and you lose your period. Estrogen levels also decrease to a level where bone regeneration is stunted, which can mean bone loss leading to increased risk of stress fractures and even osteoporosis.
Mathematic example:
Example woman:
140 lbs
27% bodyweight
102 lbs LBM
13.6 x 102 lbs = 1387 net calories would be tipping point
I understand that but my question is that if I'm eating 1400-1700 calories a day does it matter that I have three days a week where exercise puts me at a huge calorie deficit? If just those three days are going to cause huge muscle loss then I would be willing to force myself to eat more. I am eating 20-30 calories per kg of lean mass, it's just that I have some really big calorie burn days.
You didn't read and absorb what I wrote. Your energy availability is below 20-30 calories per kg of lean mass when you eat 1500 and burn 1500. You are risking bone health, which is as important as muscle. But it sounds like you are determined to eat too little and exercise too much. Do what you want. Good luck with your bone fracture goals of 2016.12 -
I just did a quick calculation, supposing your only exercise is those 1500 per day for 3 days, you are netting 800 calories per day. That's a big old no. If you do other exercise on other days, that is reduced again. If you are someone who gets quite a lot of incidental steps in a day, it further reduces it.
I hope at the very least you are also doing some strength training as all that cardio is not supporting lean mass retention.
Bottom line, you need to eat more. If this has always been your approach to weight loss it isn't any wonder you keep losing muscle.
Again, you need to look at overall averages and your numbers are worrying.7 -
The real tell will be how much weight you are losing per week. Starvation mode is not a thing in the short term - you would need to have a large deficit consistently over a long period of time, and all that would do is slow your metabolism, not stop you from losing weight.
If the info in your profile is correct, you have 35 lbs to go? You should be shooting for 1 lb per week. If you are consistently losing faster, you need to eat more. I think the healthy limit that is always mentioned is 1% of your body weight per week, but that would be the upper limit, fastest you should go. If you are prioritizing muscle-sparing, I think 1 lb would be the general advice.
Depending on how accurate your logging is, and how inflated your calorie burns are (both of which are likely, it happens all the time!), your deficit might not be as big as it seems.
Profile info is correct. Calorie logging is spot on based on nutrition labels and measuring/weighing food. Exercise calories are based on MFP and usually compared to other sites to verify caloric burn. Thing is I don't seem to be losing weight (other than the initial loss the first week back)...thus the hesitancy to eat back more of those exercise calories.0 -
The real tell will be how much weight you are losing per week. Starvation mode is not a thing in the short term - you would need to have a large deficit consistently over a long period of time, and all that would do is slow your metabolism, not stop you from losing weight.
If the info in your profile is correct, you have 35 lbs to go? You should be shooting for 1 lb per week. If you are consistently losing faster, you need to eat more. I think the healthy limit that is always mentioned is 1% of your body weight per week, but that would be the upper limit, fastest you should go. If you are prioritizing muscle-sparing, I think 1 lb would be the general advice.
Depending on how accurate your logging is, and how inflated your calorie burns are (both of which are likely, it happens all the time!), your deficit might not be as big as it seems.
Profile info is correct. Calorie logging is spot on based on nutrition labels and measuring/weighing food. Exercise calories are based on MFP and usually compared to other sites to verify caloric burn. Thing is I don't seem to be losing weight (other than the initial loss the first week back)...thus the hesitancy to eat back more of those exercise calories.
If you aren't losing weight, you aren't at a deficit, so your numbers are off. Honestly, 99 times out of 100 it's logging errors, but if not, it means your TDEE is not what the calculators would guess it is.
But considering the exercise you are doing and the weight you still have to lose, it's not likely you are actually eating 1500, just my thoughts
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I understand that but my question is that if I'm eating 1400-1700 calories a day does it matter that I have three days a week where exercise puts me at a huge calorie deficit? If just those three days are going to cause huge muscle loss then I would be willing to force myself to eat more. I am eating 20-30 calories per kg of lean mass, it's just that I have some really big calorie burn days.You didn't read and absorb what I wrote. Your energy availability is below 20-30 calories per kg of lean mass when you eat 1500 and burn 1500. You are risking bone health, which is as important as muscle. But it sounds like you are determined to eat too little and exercise too much. Do what you want. Good luck with your bone fracture goals of 2016.
This only occurs 3 days a week. IF I was determined to eat too little and exercise too much I wouldn't be seeking help/information. Your sarcasm wasn't necessary or welcomed. I could also say you didn't absorb what I wrote.If just those three days are going to cause huge muscle loss then I would be willing to force myself to eat more.0 -
Everyone has told you it's a bad idea, and some even provided links. It's not the answer you wanted to hear, but it's the right answer. It's a bad combination to do for extended periods of time (even if only 3x/week)5
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The real tell will be how much weight you are losing per week. Starvation mode is not a thing in the short term - you would need to have a large deficit consistently over a long period of time, and all that would do is slow your metabolism, not stop you from losing weight.
If the info in your profile is correct, you have 35 lbs to go? You should be shooting for 1 lb per week. If you are consistently losing faster, you need to eat more. I think the healthy limit that is always mentioned is 1% of your body weight per week, but that would be the upper limit, fastest you should go. If you are prioritizing muscle-sparing, I think 1 lb would be the general advice.
Depending on how accurate your logging is, and how inflated your calorie burns are (both of which are likely, it happens all the time!), your deficit might not be as big as it seems.
Profile info is correct. Calorie logging is spot on based on nutrition labels and measuring/weighing food. Exercise calories are based on MFP and usually compared to other sites to verify caloric burn. Thing is I don't seem to be losing weight (other than the initial loss the first week back)...thus the hesitancy to eat back more of those exercise calories.
When did you last see a loss and how much was that loss? Is the exercise, particularly at the level it is, new or coming back after a break?0 -
I appreciate the replies. But what I'm really trying to find out is will doing this a couple of times a week cause excessive muscle wasting? Or is that not really a concern?0
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I don't know how many times it has to be said, how many calorie average break downs you need, the answer will be the same, yes.7
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Calorie deficits in excess of 500 calories per day are known to draw your NEAT down. That happens because it reduces your muscle mass. There will always be some muscle loss as you lose a lot of weight. High, over 500, calorie deficits daily simply lose more than necessary.0
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What you are describing could lead to Hypoglycemia. You can actually pass out or even go into a coma because of that. Besides which, you wouldn't be getting the full benefits of exercise if you don't provide your body with the building blocks it needs to repair itself.4
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Studies are showing that when energy availability decrease to a level below 20-30 calories per kg of lean mass (9.6-13.6 calories per lb), your system starts to adapt. Note that these adaptations begin within days of eating like this. It doesn't take weeks or months. One of the big adaptations is that your reproductive system senses that now is not a good time to reproduce and you lose your period. Estrogen levels also decrease to a level where bone regeneration is stunted, which can mean bone loss leading to increased risk of stress fractures and even osteoporosis.
Mathematic example:
Example woman:
140 lbs
27% bodyweight
102 lbs LBM
13.6 x 102 lbs = 1387 net calories would be tipping pointAn although I appreciate you taking the time to post links they are not relevant to me or my question. My question/concern is muscle loss.
How is this NOT relevant to your question? Do you think you're going to keep building muscle while your hair falls out and your bones get brittle?
Muscles are expensive. It takes a lot of energy (read that as calories) to build them. And to maintain them, too. Every time you work out, you damage them, and your body requires plenty of energy (again that's calories) and protein to rebuild them. Having muscle isn't a matter of wishful thinking, it's a matter of eating and exercising to support them.5 -
I think it would depend on what calorie level you were eating at .. 1500 per day times three 4500 per week .. I have about 5250 per week trying for 1.5 per week loss .. .. so if your eating at maintaince every day and using this at calore reduction ??
Good luck1 -
The answer is yes...and yes to the other comment that you're not eating enough to support your training. It just sounds like a big bunch of wrong.0
This discussion has been closed.
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