How does cardio cause muscle loss?
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The cardio didnt burn off all his muscle but lets not pretend that it built it all either.
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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.
There's a couple of studies out there looking at retaining muscle mass in dieting pre-obese and obese individuals that seem to disagree unless you take diet into consideration.
The studies were primarily looking at the effect of protein intake. Basically, if you eat enough protein test subjects did not lose a statistically significant amount of muscle. Those who ate low protein did lose a statistically significant amount of muscle mass even with plenty of fat left to lose.
*disclaimer - I didn't spend much time going over the studies, so perhaps they were poorly run or have been contradicted ...0 -
Right, because he doesn't spend just as many hours in the weight room. You're delusional if you think he doesn't.0 -
Unfortunately that's not true. Anyone that loses weight WILL lose some muscle along with fat (unless you're using PED's and even then there's still some muscle loss). Just like adding muscle will involve adding fat, it works in reverse.prdavies1949 wrote: »Its a load of rubbish promulgated by those who like to pick things up and put them down again. I have lost over 100lbs and believe me that was all fat. I now have more muscle than I have ever had and I haven't lifted anything. (Stands back and waits for flaming)
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Pretty much this. It also is going to depend on whether or not one focuses on not losing muscle. Lots of leg endurance athletes don't do upper body work because they don't need the extra mass/weight and because they use little of their upper body strength to compete or do their preferred sport.tigersword wrote: »It's basic physiology. The human body actually prefers to save fat and lose muscle in a starvation situation (yes, dieting is technically starvation.) This is because the body can live much longer with fat stores than without them.
Average weight loss is about 75 % fat and 25% lean mass (muscle, water, bone, etc.) The larger the deficit, the more that ratio swings toward lean mass. Without proper fuel, cardio can lead to massive deficits that can lead to serious muscle loss.
As mentioned before, if the muscle isn't used and if deficits are high enough, then lean muscle gets reduced.
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Oh trust that there are many people in the gym who DON'T do leg work.jeremywm1977 wrote: »It doesn't cause it, it just does little to prevent it, and in certain circumstances can increase it.
This probably sums it up best.
If you want to do only cardio like treadmill, elliptical, or running, and you enjoy it and can maintain such a routine, and such a routine has caused you to lose weight..........then great, you're already doing more than the next person doing nothing.
As far as the physiology behind your question. If, for instance, all you are doing is running, then over time you are going to become a more efficient runner. Unfortunately, your body is going to work to strengthen those muscles needed to run to create an improved economy of motion, but those muscles not used in your selected workout are going to atrophy.......you body will adapt to improve your selected method of exercise by burning the muscle no longer needed.
Yes, if you maintain a calorie deficit, you are going to appear more muscular-ish, but that is because the fat that previously covered those muscles is burning too.......it's kind of a lose/win.......you're burning fat, but you're also burning muscle which is probably a greater component in burning fat than that 30 minute run you just did.
In the end, do what you want, do what you can maintain and consistently do, and anybody who wishes to tell you you're doing wrong can just go away.
This was helpful too. I think what you're saying is that running strengthens leg muscles, but doens't really do anything for the muscles that aren't really used much in running. That makes sense to me, but wouldn't the same apply to strength training? Calves and quads come immediately to mind. I'm guessing that legs kind of get the short end of the stick in strength training.
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This is correct. BodyPump is a good example of endurance lifting.20yearsyounger wrote: »You can also target slow twitch muscles when lifting. It depends on how heavy you lift, your reps, etc. When lifting, you can consider whether or not you want to increase/maintain power, endurance, or strength. You don't always have to progressively overload.
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Just about every cardio exercise involves resistance. Whether it's running, biking, swimming,etc. The "degree" of resistance will help to dictate if it's more aerobic or anaerobic.Need2Exerc1se wrote: »Cardio is such a broad term. There are many exercises that are called cardio that also provide resistance.
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Strength is built on progressive overload and involves fast twitch muscle fibers. Lifting a light weight 100 is muscular endurance training and involves slow twitch muscle fibers."Need2Exerc1se wrote:
I do disagree that lifting a light weight 100 times could not build strength though.
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Depends on what you're comparing it to. Flexibility isn't as important in the 100 meter dash as it is to a ballet dancer. And vice versa when it comes to speed.concordancia wrote: »SteveJWatson wrote: »There are three main aspects too fitness - Strength, speed and endurance.
People seem to train the last two a lot and miss the first one.
Flexibility. Even more important than speed.
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Imbalance in quad vs hamstring training. Most people pull hamstrings because they aren't trained as hard as quads.JeffseekingV wrote: »SteveJWatson wrote: »There are three main aspects too fitness - Strength, speed and endurance.
People seem to train the last two a lot and miss the first one.
I pulled my hamstring try to do HITT sprinting to improve 1)
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I would say that good form on any exercise will lead to better flexibility. There are lots of female dancers who are extremely flexible, yet still squat incorrectly.tigersword wrote: »concordancia wrote: »SteveJWatson wrote: »There are three main aspects too fitness - Strength, speed and endurance.
People seem to train the last two a lot and miss the first one.
Flexibility. Even more important than speed.
I would actually venture to say flexibility is the most important (though also the most ignored) part of fitness. Most of the injuries I've read about (and experienced myself) were caused mainly by lack of flexibility leading to bad form and other mechanical issues that resulted in injury.
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Keep the deficit reasonable enough, and you may need not have to worry about it at all.
http://fampra.oxfordjournals.org/content/16/2/196.full
"All three intervention groups had a significant decline in body mass at 6 weeks, and again at 12 weeks for an 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 (standard deviations only presented graphically). By 12 weeks there were also significant decreases in percentage body fat: 5.8, 8.0 and 4.3%, respectively. However, there were no significant differences between groups. There were no significant changes in fat-free mass in any of the groups at any time period. There were also no significant changes in resting metabolic rate (measured in absolute terms or relative to body mass) within groups over time or between groups over time. "
"The findings regarding no loss of fat-free mass in the diet-only group are surprising, as some degree of obligatory loss of fat-free mass is expected with significant weight loss."
"Much of the work regarding changes in fat-free mass and resting metabolic rate in response to hypocaloric diets have implemented diets containing 800–1200 kilocalories per day. Such low calorie diets result in a severe calorie deficit and the need to oxidize protein. Information regarding the participants' dietary intake in this study is scant. Only mean intakes per group for the entire 12-week period are presented. These intakes are approximately 250– 380 kilocalories less than mean baseline resting metabolic rates. In addition, dietary information is based on self-report, and there is a strong likelihood of underreporting of food intake in obese people.3 Systematic errors in this direction would lessen the actual calorie deficit. These relatively small calorie deficits may have enabled subjects to spare protein from oxidation."0 -
That's crazy. Thanks for sharing. Looks like the diet + aerobic group lost the most body fat % wise, interesting.0
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Jebuz.... this thread is still going???
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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%.0 -
Just about every cardio exercise involves resistance. Whether it's running, biking, swimming,etc. The "degree" of resistance will help to dictate if it's more aerobic or anaerobic.
Anecdotally, I do notice strength increases from time in the pool. Three months ago, it wasn't too easy to lift a 5 gallon water bottle and manipulate it onto the water cooler. Now, I'm throwing it around like it's nothing.
Perhaps it is nothing compared to strength increases I would see pumping iron, but they exist.
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I think just because your deficit can get too high and you end up burning both fat and muscle mass. I'm sure it builds muscle in legs mostly but if you aren't eating back calories I can see how you could lose muscle too.0
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As I mentioned degree of resistance makes a difference. There's obviously more resistance in swimming vs running with nothing in your hands. The body adapts to resistance quite quickly which is why people stop getting DOMS if they lift the same resistance time in and time out consistently.NoelFigart1 wrote: »Just about every cardio exercise involves resistance. Whether it's running, biking, swimming,etc. The "degree" of resistance will help to dictate if it's more aerobic or anaerobic.
Anecdotally, I do notice strength increases from time in the pool. Three months ago, it wasn't too easy to lift a 5 gallon water bottle and manipulate it onto the water cooler. Now, I'm throwing it around like it's nothing.
Perhaps it is nothing compared to strength increases I would see pumping iron, but they exist.
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