How does cardio cause muscle loss?
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yopeeps025 wrote: »
You kind of just said that, without reading the article, also interesting0 -
yopeeps025 wrote: »
Actually, in the first study summary I quoted parts of - there was no loss of LBM.
And since the weight lost was pretty close - there's not that much difference in calorie deficit. Since they were body matched too before random assignment to which group, even the deficit as a % of BMR was about the same (not the same as % of TDEE though). Over 12 weeks.
"average total weight loss of 6.2 kg in the diet-only group, 6.8 kg for the diet plus aerobic exercise group, and 7.0 kg for the diet, aerobic and resistance training group"
That would be a deficit of 570, 624, and 643 respectively, since they only lost fat, and using the 3500 cal/lb of fat. That's pretty close deficit amounts, within 11%.
I wish there was more information on the subjects involved. The fact that there was no lbm loss from any group, yet the strength training group lost the most weight, but had the smallest percentage of fat loss, is an interesting contradiction.
Also, they were eating approximately 1200 calories with 70% carbohydrates. That makes sense to me as LBM sparing for a couple reasons. The high percentage of carbs allows the body to utilize the protein ingested for lbm maintenance, rather than catabolizing it for glucose, while at the same time, the high level of carbs helps maintain glycogen levels, which would also register as lbm loss.
That second point I think is rather important in general, as people get way too hung up on LBM=MUSCLE. If you exhaust glycogen stores, and end up losing 10 pounds or so from glycogen and water, you've lost 10 pounds of LBM, but no muscle loss.0 -
jeremywm1977 wrote: »Is there a minimum of resistance/strength training that one needs per week in order to help maintain current muscle mass? I mean I know why I should do it, but I now prefer to run then lift weights. I was lifting 3 times a week months ago, but would 2 full body days be enough? Are body weight exercises enough when eating in a deficit?
I'm a big proponent of body weight exercises.......so much variety, so much more money in your pocket (money saved from not buying equipment or paying for gym memberships).
Pound for pound, nothing beats the push up or burpee, or perhaps the burpee push up. No weights needed for that beast........and you work your upper body, lower body, core, plus it's cardio. I absolutely love the Prison Cell Push Up from P90X.......look it up on YouTube (I checked, it's there) and give it a try.
Get a push up resistance band and boy that's a hard work out!0 -
tigersword wrote: »yopeeps025 wrote: »
Actually, in the first study summary I quoted parts of - there was no loss of LBM.
And since the weight lost was pretty close - there's not that much difference in calorie deficit. Since they were body matched too before random assignment to which group, even the deficit as a % of BMR was about the same (not the same as % of TDEE though). Over 12 weeks.
"average total weight loss of 6.2 kg in the diet-only group, 6.8 kg for the diet plus aerobic exercise group, and 7.0 kg for the diet, aerobic and resistance training group"
That would be a deficit of 570, 624, and 643 respectively, since they only lost fat, and using the 3500 cal/lb of fat. That's pretty close deficit amounts, within 11%.
I wish there was more information on the subjects involved. The fact that there was no lbm loss from any group, yet the strength training group lost the most weight, but had the smallest percentage of fat loss, is an interesting contradiction.
Also, they were eating approximately 1200 calories with 70% carbohydrates. That makes sense to me as LBM sparing for a couple reasons. The high percentage of carbs allows the body to utilize the protein ingested for lbm maintenance, rather than catabolizing it for glucose, while at the same time, the high level of carbs helps maintain glycogen levels, which would also register as lbm loss.
That second point I think is rather important in general, as people get way too hung up on LBM=MUSCLE. If you exhaust glycogen stores, and end up losing 10 pounds or so from glycogen and water, you've lost 10 pounds of LBM, but no muscle loss.
That is a critical distinction that gets lost/ignored far too often.
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It doesn't cause it, it just does little to prevent it, and in certain circumstances can increase it.
Being in a calorie deficit causes muscle loss (as well as fat loss) and cardio increases that deficit making the loss occur faster.
There's more to it than this, but one reason muscle is lost in a deficit is that muscle requires more energy to maintain than fat does. So when your body is in a calorie deficit it will burn muscle for energy as well as fat in order to reduce energy expenditure and therefore reduce the deficit.
Weightlifting also increases calorie expenditure and therefore the deficit, but unlike cardio it also encourages your body to hold on to the muscle (it thinks it needs it).
So a lot of people prefer weightlifting to cardio for fat loss.
A bit of both would be the ideal; weightlifting to keep the muscle, cardio to increase calorie deficit.
This is the most informative and thought out answer I've see so far. I bolded part of it because that is the part that I've always had a problem with. Why on earth would the body burn muscle instead of fat since fat's purpose is to store energy for use when we don't have fuel.
It doesn't, until there isn't much fat left to burn. The less fat there is to burn, the more preferentially it will burn lightly used muscle, but at that point there is little enough fat left that dieting may have already come to an end.
I dont' believe that is correct, (meaning its not the only time) but thank you for saying that. Because it reminds me of the instance where cardio can in fact 'eat' muscle. if you deplete glycogen stores, and your exercising at a pace where your body can't support aerobic respiration, then your body will start using protein as a fuel source, and they may take that from muscle.
also I there is definitely the possibility of your body utilizing your muscles for fuel over the course of the day when in a deficit, that's the biggest reason to weight train while in a deficit. perhaps the lower your body fat % the more likely this maybe, but its definitely a possibility regardless of your bf %0 -
tigersword wrote: »yopeeps025 wrote: »
Actually, in the first study summary I quoted parts of - there was no loss of LBM.
And since the weight lost was pretty close - there's not that much difference in calorie deficit. Since they were body matched too before random assignment to which group, even the deficit as a % of BMR was about the same (not the same as % of TDEE though). Over 12 weeks.
"average total weight loss of 6.2 kg in the diet-only group, 6.8 kg for the diet plus aerobic exercise group, and 7.0 kg for the diet, aerobic and resistance training group"
That would be a deficit of 570, 624, and 643 respectively, since they only lost fat, and using the 3500 cal/lb of fat. That's pretty close deficit amounts, within 11%.
I wish there was more information on the subjects involved. The fact that there was no lbm loss from any group, yet the strength training group lost the most weight, but had the smallest percentage of fat loss, is an interesting contradiction.
Also, they were eating approximately 1200 calories with 70% carbohydrates. That makes sense to me as LBM sparing for a couple reasons. The high percentage of carbs allows the body to utilize the protein ingested for lbm maintenance, rather than catabolizing it for glucose, while at the same time, the high level of carbs helps maintain glycogen levels, which would also register as lbm loss.
That second point I think is rather important in general, as people get way too hung up on LBM=MUSCLE. If you exhaust glycogen stores, and end up losing 10 pounds or so from glycogen and water, you've lost 10 pounds of LBM, but no muscle loss.
That is a critical distinction that gets lost/ignored far too often.
As does the distinction between wet and dry muscle!
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never heard that before... one is when you are dehydrated i suppose? lol
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No_Finish_Line wrote: »never heard that before... one is when you are dehydrated i suppose? lol
LOL, well something like that but dry muscle is muscle tissue only without water or glycogen so it can weight a lot less. I can't remember the general ratios but it can but quite a bit when the muscle is full of glycogen, creatine, sodium and other water attracting compounds.0 -
Wheelhouse15 wrote: »No_Finish_Line wrote: »never heard that before... one is when you are dehydrated i suppose? lol
LOL, well something like that but dry muscle is muscle tissue only without water or glycogen so it can weight a lot less. I can't remember the general ratios but it can but quite a bit when the muscle is full of glycogen, creatine, sodium and other water attracting compounds.
I wonder how significant that difference is for the average person in normal life.
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Wheelhouse15 wrote: »No_Finish_Line wrote: »never heard that before... one is when you are dehydrated i suppose? lol
LOL, well something like that but dry muscle is muscle tissue only without water or glycogen so it can weight a lot less. I can't remember the general ratios but it can but quite a bit when the muscle is full of glycogen, creatine, sodium and other water attracting compounds.
that's interesting. I'm wondering what the application is. i guess this is an aspect of certain studies? i guess I'm just getting hung up on the fact that your muscles probably never have zero water, so I'm wondering at what point they are technically considered 'dry'
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No_Finish_Line wrote: »Wheelhouse15 wrote: »No_Finish_Line wrote: »never heard that before... one is when you are dehydrated i suppose? lol
LOL, well something like that but dry muscle is muscle tissue only without water or glycogen so it can weight a lot less. I can't remember the general ratios but it can but quite a bit when the muscle is full of glycogen, creatine, sodium and other water attracting compounds.
that's interesting. I'm wondering what the application is. i guess this is an aspect of certain studies? i guess I'm just getting hung up on the fact that your muscles probably never have zero water, so I'm wondering at what point they are technically considered 'dry'
Agreed.
It feels to me like one of those cases where something was studied in a lab that would never/rarely happen in real life.0 -
Wheelhouse15 wrote: »No_Finish_Line wrote: »never heard that before... one is when you are dehydrated i suppose? lol
LOL, well something like that but dry muscle is muscle tissue only without water or glycogen so it can weight a lot less. I can't remember the general ratios but it can but quite a bit when the muscle is full of glycogen, creatine, sodium and other water attracting compounds.
I wonder how significant that difference is for the average person in normal life.
Well, glycogen alone attracts 4g water weight per g of glycogen weight IIRC so it can be substantive. If you can store say 1g of glycogen per g weight of muscle than you've got a 5:1 ratio right there. Unfortunately, I can't recall offhand what the actual wet dry ratio is and there are various factors since glycogen can deplete and fill dynamically through the day but I would imagine at least 4:1 would be a good guess.0 -
tigersword wrote: »yopeeps025 wrote: »
Actually, in the first study summary I quoted parts of - there was no loss of LBM.
And since the weight lost was pretty close - there's not that much difference in calorie deficit. Since they were body matched too before random assignment to which group, even the deficit as a % of BMR was about the same (not the same as % of TDEE though). Over 12 weeks.
"average total weight loss of 6.2 kg in the diet-only group, 6.8 kg for the diet plus aerobic exercise group, and 7.0 kg for the diet, aerobic and resistance training group"
That would be a deficit of 570, 624, and 643 respectively, since they only lost fat, and using the 3500 cal/lb of fat. That's pretty close deficit amounts, within 11%.
I wish there was more information on the subjects involved. The fact that there was no lbm loss from any group, yet the strength training group lost the most weight, but had the smallest percentage of fat loss, is an interesting contradiction.
Also, they were eating approximately 1200 calories with 70% carbohydrates. That makes sense to me as LBM sparing for a couple reasons. The high percentage of carbs allows the body to utilize the protein ingested for lbm maintenance, rather than catabolizing it for glucose, while at the same time, the high level of carbs helps maintain glycogen levels, which would also register as lbm loss.
That second point I think is rather important in general, as people get way too hung up on LBM=MUSCLE. If you exhaust glycogen stores, and end up losing 10 pounds or so from glycogen and water, you've lost 10 pounds of LBM, but no muscle loss.
That is a critical distinction that gets lost/ignored far too often.
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No_Finish_Line wrote: »Wheelhouse15 wrote: »No_Finish_Line wrote: »never heard that before... one is when you are dehydrated i suppose? lol
LOL, well something like that but dry muscle is muscle tissue only without water or glycogen so it can weight a lot less. I can't remember the general ratios but it can but quite a bit when the muscle is full of glycogen, creatine, sodium and other water attracting compounds.
that's interesting. I'm wondering what the application is. i guess this is an aspect of certain studies? i guess I'm just getting hung up on the fact that your muscles probably never have zero water, so I'm wondering at what point they are technically considered 'dry'
Agreed.
It feels to me like one of those cases where something was studied in a lab that would never/rarely happen in real life.
Very true, but the gaining or loss of dry muscle is what is often studied in studies of training methods, impact of diets, etc.0 -
I haven't seen anything on here about heart rate training so I'll chime in with a few things I've learned.
I'm 45 and using the heart rate zones my fat burning zone is at it's most efficient at around 117 bpm. I tried this last night actually and ran much, much slower than normal to keep it at 117. I put in some interval sprints of 2 minutes just to keep the sweat on. Once you go past that fat burning zone your body will begin using glycogen stores and muscle as well as fat. The higher the heart rate, the less fat and more muscle it will use. And the longer you run the more it will avoid fat for energy. The body holds on to the fat at that point to protect itself.
The plan you mentioned of 3 days cardio and 3 days lifting is good and also make sure you eat enough when you do a hard cardio day.
I train for triathlons and was surprised to learn how little hard running was built into the training plan vs. lower heart rate tempo running. Knowing what I know now about exercise AND nutrition, it makes more and more sense.
Good luck.0 -
No_Finish_Line wrote: »It doesn't cause it, it just does little to prevent it, and in certain circumstances can increase it.
Being in a calorie deficit causes muscle loss (as well as fat loss) and cardio increases that deficit making the loss occur faster.
There's more to it than this, but one reason muscle is lost in a deficit is that muscle requires more energy to maintain than fat does. So when your body is in a calorie deficit it will burn muscle for energy as well as fat in order to reduce energy expenditure and therefore reduce the deficit.
Weightlifting also increases calorie expenditure and therefore the deficit, but unlike cardio it also encourages your body to hold on to the muscle (it thinks it needs it).
So a lot of people prefer weightlifting to cardio for fat loss.
A bit of both would be the ideal; weightlifting to keep the muscle, cardio to increase calorie deficit.
This is the most informative and thought out answer I've see so far. I bolded part of it because that is the part that I've always had a problem with. Why on earth would the body burn muscle instead of fat since fat's purpose is to store energy for use when we don't have fuel.
It doesn't, until there isn't much fat left to burn. The less fat there is to burn, the more preferentially it will burn lightly used muscle, but at that point there is little enough fat left that dieting may have already come to an end.
I dont' believe that is correct, (meaning its not the only time) but thank you for saying that. Because it reminds me of the instance where cardio can in fact 'eat' muscle. if you deplete glycogen stores, and your exercising at a pace where your body can't support aerobic respiration, then your body will start using protein as a fuel source, and they may take that from muscle.
also I there is definitely the possibility of your body utilizing your muscles for fuel over the course of the day when in a deficit, that's the biggest reason to weight train while in a deficit. perhaps the lower your body fat % the more likely this maybe, but its definitely a possibility regardless of your bf %
I think there's a slight misconception here. Muscle loss doesn't necessarily come from the body eating muscle to fuel itself. Muscle is constantly being broken and down and rebuilt (cell death and replacement, damage from exercise, etc.) I think the area where muscle loss becomes an issue is when the muscle is broken down from normal living, but due to not enough calories consumed and/or not enough protein and/or carbs consumed the muscle is not able to be rebuilt.0 -
lchadwick2 wrote: »I haven't seen anything on here about heart rate training so I'll chime in with a few things I've learned.
I'm 45 and using the heart rate zones my fat burning zone is at it's most efficient at around 117 bpm. I tried this last night actually and ran much, much slower than normal to keep it at 117. I put in some interval sprints of 2 minutes just to keep the sweat on. Once you go past that fat burning zone your body will begin using glycogen stores and muscle as well as fat. The higher the heart rate, the less fat and more muscle it will use. And the longer you run the more it will avoid fat for energy. The body holds on to the fat at that point to protect itself.
The plan you mentioned of 3 days cardio and 3 days lifting is good and also make sure you eat enough when you do a hard cardio day.
I train for triathlons and was surprised to learn how little hard running was built into the training plan vs. lower heart rate tempo running. Knowing what I know now about exercise AND nutrition, it makes more and more sense.
Good luck.
You maximize your aerobic system gains around 65 to 75% of your 5k speed. I just read a good article on the benefits of slow running with the reasons behind this but I can't seem to find it right now. I'll link it if I can find it soon.0 -
tigersword wrote: »No_Finish_Line wrote: »It doesn't cause it, it just does little to prevent it, and in certain circumstances can increase it.
Being in a calorie deficit causes muscle loss (as well as fat loss) and cardio increases that deficit making the loss occur faster.
There's more to it than this, but one reason muscle is lost in a deficit is that muscle requires more energy to maintain than fat does. So when your body is in a calorie deficit it will burn muscle for energy as well as fat in order to reduce energy expenditure and therefore reduce the deficit.
Weightlifting also increases calorie expenditure and therefore the deficit, but unlike cardio it also encourages your body to hold on to the muscle (it thinks it needs it).
So a lot of people prefer weightlifting to cardio for fat loss.
A bit of both would be the ideal; weightlifting to keep the muscle, cardio to increase calorie deficit.
This is the most informative and thought out answer I've see so far. I bolded part of it because that is the part that I've always had a problem with. Why on earth would the body burn muscle instead of fat since fat's purpose is to store energy for use when we don't have fuel.
It doesn't, until there isn't much fat left to burn. The less fat there is to burn, the more preferentially it will burn lightly used muscle, but at that point there is little enough fat left that dieting may have already come to an end.
I dont' believe that is correct, (meaning its not the only time) but thank you for saying that. Because it reminds me of the instance where cardio can in fact 'eat' muscle. if you deplete glycogen stores, and your exercising at a pace where your body can't support aerobic respiration, then your body will start using protein as a fuel source, and they may take that from muscle.
also I there is definitely the possibility of your body utilizing your muscles for fuel over the course of the day when in a deficit, that's the biggest reason to weight train while in a deficit. perhaps the lower your body fat % the more likely this maybe, but its definitely a possibility regardless of your bf %
I think there's a slight misconception here. Muscle loss doesn't necessarily come from the body eating muscle to fuel itself. Muscle is constantly being broken and down and rebuilt (cell death and replacement, damage from exercise, etc.) I think the area where muscle loss becomes an issue is when the muscle is broken down from normal living, but due to not enough calories consumed and/or not enough protein and/or carbs consumed the muscle is not able to be rebuilt.
Correct. And if one truly does become glycogen depleted--something that rarely happens and few people on this site have ever experienced--the body will use some protein to supply those parts of the body that only derive energy via glycolysis. However the bulk of energy production is derived via beta oxidation from fat stores. Because of the limits in rate of energy production via beta oxidation, the body can only work at a max of 50-60% of VO2.max. It's called "hitting the wall" and it's not something you want to sustain for very long.
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lchadwick2 wrote: »I haven't seen anything on here about heart rate training so I'll chime in with a few things I've learned.
I'm 45 and using the heart rate zones my fat burning zone is at it's most efficient at around 117 bpm. I tried this last night actually and ran much, much slower than normal to keep it at 117. I put in some interval sprints of 2 minutes just to keep the sweat on. Once you go past that fat burning zone your body will begin using glycogen stores and muscle as well as fat. The higher the heart rate, the less fat and more muscle it will use. And the longer you run the more it will avoid fat for energy. The body holds on to the fat at that point to protect itself.
The plan you mentioned of 3 days cardio and 3 days lifting is good and also make sure you eat enough when you do a hard cardio day.
I train for triathlons and was surprised to learn how little hard running was built into the training plan vs. lower heart rate tempo running. Knowing what I know now about exercise AND nutrition, it makes more and more sense.
Good luck.
The whole "fat burning zone" is a very seductive concept with only one small, but significant, problem: it's wrong.
The substrate mix used during exercise has no significant long-term effect--neither stored body fat nor muscle. The total amount used is just not large enough, and the body sorts everything out in the rest of the day following the workout anyhow.
Now using a "fat burning" or endurance zone as part of a training plan can be very effective. The plan you describe can be a good one. It just doesn't have any effect on body fat outside of the calories burned.
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I think this thread got way too complicated and pointless. Too much science will totally ruin a perfectly good plan to eat well and train hard with great results. No one really really cares about wet muscles, dry muscles, blah blah blah. Go outside and run hard. Go to the gym and lift hard. Go home and eat right. (And yeah, you know what that means...it's common sense). Losing weight and getting in shape is not complicated. People make it hard because they want shortcuts and do not want to exercise self-discipline. 25 years ago I competed in some natural bodybuilding contests. My trainer and I just pounded the crap out of the weights, worked in some cardio and cut the crap out of my diet.... and it actually worked. In a relatively short period of time. And without measuring my food, without macros, without HRMs, or any of this other techie nonsense. We just worked hard, had fun and didn't over-think it.0
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