You will lose your lean mass if you just do cardio

kirstyg1980

I noticed more body changes as I decreased cardio to focus on more strength training. I don't have flab around my belly and hips anymore like some women who weigh a lot less. I'm happier with my body than I ever thought I would be without reaching my goal weight yet and I think that is mostly because of strength training

Exactly how I feel, in just 4 weeks of lifting heavy

LaMujerMasBonitaDelMundo

I noticed more body changes as I decreased cardio to focus on more strength training. I don't have flab around my belly and hips anymore like some women who weigh a lot less. I'm happier with my body than I ever thought I would be without reaching my goal weight yet and I think that is mostly because of strength training

Me too.

See we need to do both cardio & strength training for our overall health. A lot especially women have confused strength training to only mean heavy weight lifting. Strength training comes in different types such as weight lifting, yoga, pilates, resistance band & body weight exercises. And when you say heavy weight lifting, it doesn't automatically mean those muscle heads lifting barbells or dumbbells 3x of their body weight. It only means that the weight should be challenging enough for your muscles that you can complete in good form up to 6-8 reps & that you should feel the fatigue after the last rep. Cardio can only become catabolic when it is overdone.

carld256

And what was the protein intake, if I may ask?

No idea. I haven't been able to find any real information on the study itself, just lots of references to it.

crisanderson27

And what was the protein intake, if I may ask?

No idea. I haven't been able to find any real information on the study itself, just lots of references to it.

Well, that would be THE critical factor in my opinion. If you're exercising hard, and not getting your protein intake in...it doesn't matter WHAT you're doing, you're going to lose muscle mass.

I can guarantee (or would rather) if they had adequate protein intake, the results wouldn't be the same.

Glucocorticoid

Does anyone have a link to the original Penn State study that's been mentioned? Because this site seems to claim the opposite of what people are saying.

STUDY #1: In this study, conducted at Penn State University, a group of women took part in a 12-week program of diet and exercise [2]. The women were assigned to one of four groups:

• The first group served as a control group, and did nothing.

• Group two followed a low-fat, high-carbohydrate diet.

• Group three combined the same diet with regular aerobic exercise.

• The fourth group also followed the same diet, but added aerobic and resistance exercise (weight training).

As you might imagine, all three groups lost weight.

• The diet-only group lost 13.6 pounds.

• The diet plus aerobic exercise group lost 15 pounds.

• The women combining diet with resistance and aerobic exercise lost 15.4 pounds.

However, the loss of fat was greatest in the women who combined a low-calorie diet with aerobic exercise.

In fact, the women who trained with weights actually lost 3.7 pounds of muscle.

http://www.thefactsaboutfitness.com/news/combo.htm

Did you actually read the study? If you did, you'd see how wrong that interpretation is.

Glucocorticoid

And what was the protein intake, if I may ask?

No idea. I haven't been able to find any real information on the study itself, just lots of references to it.

Well, that would be THE critical factor in my opinion. If you're exercising hard, and not getting your protein intake in...it doesn't matter WHAT you're doing, you're going to lose muscle mass.

I can guarantee (or would rather) if they had adequate protein intake, the results wouldn't be the same.

There's nothing wrong with the study. Here's a quote from the conclusion:

Surprisingly, all dietary groups experienced similar reductions in body mass (−6.2, −6.8, and −7.0 kg for D, DE, and DES groups, respectively) and body composition (−5.8, −8.0, and −4.3% in D, DE, and DES groups, respectively), whereas fat-free mass remained relatively constant (−0.1, +1.4, and −1.7 kg in D, DE, and DES groups, respectively) over the 12-wk period. Our findings of no difference in the magnitude of loss in total body mass, percent fat, and fat mass among dietary groups is in agreement with the results of Ballor and Poehlman (2), who reported in a meta-analysis of 46 studies that exercise training does not influence the loss in body mass, percent fat, or fat mass compared with dietary restriction without exercise. However, the data from the meta-analysis did show that exercise training reduces the percentage of body mass lost as fat-free mass during weight-loss regimens (2). In contrast, our data showed no loss in fat-free mass and no difference among groups. In support of our findings on fat-free mass, a number of studies using various methods of body composition such as magnetic resonance imaging (42, 43), hydrostatic weighing (3, 34), and bioelectric impedance (38) have also reported that the loss in fat-free mass is not only attenuated but maintained or increased when exercise is added to dietary restriction.

Well I take that back, there's plenty of things we need to be aware of with the study - one important point being that caloric/macronutrient intake was NOT controlled.
Nevertheless, the results aren't groundbreaking - they're actually what one would expect.We need to keep in mind the subjects of the study - overweight women with significantly high BF%. It is well documented that you can retain most, if not all, of your LBM in a deficit when you are significantly overfat, despite protein intake not being adequate and despite the lack of an adequate resistance program. As you get leaner, adequate protein intake/resistance program become more and more important. This is something the authors didn't seem to emphasize.

mfpcopine

Adding on muscle does increase metabolic rate - just not to any significant degree. The study below shows that adding on one pound of muscle means you burn an additional 6 calories per day. Gaining 10 pounds of muscle (which is not something that will happen overnight) means you burn an additional 60 calories per day.

http://www.ncbi.nlm.nih.gov/pubmed/11224660

What you've said is what I've read as well.

LadyIntrepid

Personally, I don't want to be a big muscled body builder, but I greatly prefer my higher muscle mass (and higher body fat) look to that of a lower muscle mass that many runners seem to have.



I'm the one in yellow. I prefer my arms and legs over the arms and legs of the two girls ahead of me. I'd love to be as fast as they are, because they cream my *kitten* in races. :embarassed: We're all in the same age group (35-39). They're not skinny fat. They have low body fat, but also a lower muscle mass.

And I'm not all that muscular, as you can see when relaxed in normal clothes. But I'm not anywhere near a "runner's build."

You look terrific!

Glucocorticoid

And what was the protein intake, if I may ask?

No idea. I haven't been able to find any real information on the study itself, just lots of references to it.

Read the actual study - it's free. http://jap.physiology.org/content/83/1/270.full

bcattoes

The reason you see that so many posts on MFP telling us that we will lose muscle if we do cardio only is because there is a large MFP population that comes to these forums from bodybuilding.com and/or other body building sites. You can even see the same catch phrases in many of their posts.

Of course you can keep muscle with cardio only. Muscles that are being worked regularly do not whither away, no matter how you work them.

fatboypup

cardio is KING

crisanderson27

And what was the protein intake, if I may ask?

No idea. I haven't been able to find any real information on the study itself, just lots of references to it.

Well, that would be THE critical factor in my opinion. If you're exercising hard, and not getting your protein intake in...it doesn't matter WHAT you're doing, you're going to lose muscle mass.

I can guarantee (or would rather) if they had adequate protein intake, the results wouldn't be the same.

There's nothing wrong with the study. Here's a quote from the conclusion:

Surprisingly, all dietary groups experienced similar reductions in body mass (−6.2, −6.8, and −7.0 kg for D, DE, and DES groups, respectively) and body composition (−5.8, −8.0, and −4.3% in D, DE, and DES groups, respectively), whereas fat-free mass remained relatively constant (−0.1, +1.4, and −1.7 kg in D, DE, and DES groups, respectively) over the 12-wk period. Our findings of no difference in the magnitude of loss in total body mass, percent fat, and fat mass among dietary groups is in agreement with the results of Ballor and Poehlman (2), who reported in a meta-analysis of 46 studies that exercise training does not influence the loss in body mass, percent fat, or fat mass compared with dietary restriction without exercise. However, the data from the meta-analysis did show that exercise training reduces the percentage of body mass lost as fat-free mass during weight-loss regimens (2). In contrast, our data showed no loss in fat-free mass and no difference among groups. In support of our findings on fat-free mass, a number of studies using various methods of body composition such as magnetic resonance imaging (42, 43), hydrostatic weighing (3, 34), and bioelectric impedance (38) have also reported that the loss in fat-free mass is not only attenuated but maintained or increased when exercise is added to dietary restriction.

Well I take that back, there's plenty of things we need to be aware of with the study - one important point being that caloric/macronutrient intake was NOT controlled.
Nevertheless, the results aren't groundbreaking - they're actually what one would expect.We need to keep in mind the subjects of the study - overweight women with significantly high BF%. It is well documented that you can retain most, if not all, of your LBM in a deficit when you are significantly overfat, despite protein intake not being adequate and despite the lack of an adequate resistance program. As you get leaner, adequate protein intake/resistance program become more and more important. This is something the authors didn't seem to emphasize.

Thanks Kenny...and I agree that makes much more sense. The claims being made (particularly the one in bold) didn't seem realistic to me.

AnninStPaul

I would like to see some scientific proof that you'll lose lean mass or become "skinny fat" by just doing cardio. Honestly, I haven't lifted weights since my early 20's. I've run, done yoga, done martial arts for years... I had a DEXA scan done in 2004 at 29 years of age that showed I have 120 lbs of lean mass and I had one done a few weeks ago that showed the same 120 lbs of lean mass. I haven't lifted a single weight in that time and my diet has been all over the board, two pregnancies... not to mention 8 years have passed.

So... why is it that people are told not to do cardio only? If you already have a decent muscle base, why not just burn off the fat? I don't understand. It seems pretty hard to lose muscle... there was a time I wanted to.

two pregnancies - does that mean you have had small children around the house? that's weightlifting.

nszocinski

Bump

secretlobster

Here's my N=1 example.

Went from 210lbs to 154lbs in 9 months. Calorie controlled diet with approximately 150g protein averaged for day. Exercise choices was jogging, boxing & some bodyweight resistance exercise.

I went from fat to skinny fat. I know I lost a LOT of LBM. (no dexa scans or anything but by the end I could only bench 110lbs 1rm, which I previously did sets of 10 of) If I had my choice again, I would have done it slower and included resistance training from the start.

So for me, cardio only (even though I did do some other resistance training) definitely resulted in a large loss of LBM. I really wish I had a pic of me when I was twig skinny fat but unsurprisingly, not many photos taken in that time period

Boxing is resistance training which is great for muscle retention, so it sounds like it may not have been the absence of weight training that caused you to lose LBM, but more likely, overworking yourself in your cardio sessions combined with a calorie deficit.

sthrnspirit

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magerum

I would like to see some scientific proof that you'll lose lean mass or become "skinny fat" by just doing cardio. Honestly, I haven't lifted weights since my early 20's. I've run, done yoga, done martial arts for years... I had a DEXA scan done in 2004 at 29 years of age that showed I have 120 lbs of lean mass and I had one done a few weeks ago that showed the same 120 lbs of lean mass. I haven't lifted a single weight in that time and my diet has been all over the board, two pregnancies... not to mention 8 years have passed.

So... why is it that people are told not to do cardio only? If you already have a decent muscle base, why not just burn off the fat? I don't understand. It seems pretty hard to lose muscle... there was a time I wanted to.

I dont have time to provide links and such but I can tell you this. I lost 160 lbs over the last year with just diet and cardio. My bench max went from 315lbs to 170lbs. Tell me that's not loosing lean body mass.

lastchance2010

This has been very informative and I just learned something...AWESOME!!! :drinker:

Sidesteal

Boxing is resistance training which is great for muscle retention, so it sounds like it may not have been the absence of weight training that caused you to lose LBM, but more likely, overworking yourself in your cardio sessions combined with a calorie deficit.

How is boxing resistance training?

Jacwhite22

I dont have time to provide links and such but I can tell you this. I lost 160 lbs over the last year with just diet and cardio. My bench max went from 315lbs to 170lbs. Tell me that's not loosing lean body mass.

What were you eating? How much protein? Taking a year long break from lifting(regardless of diet) will cause strength loss.......

howeclectic

Its hard to know anything for sure... but one thing I notice... Every study seems to me to be fundamentally flawed. Especially for HIGHLY motivated individuals. Yes losing weight likely will lead to lean body mass loss. However, I don't see too many reliable studies around individuals who do INTENSE cardio (Interval training, sprinting, Hockey, Etc). A lot of the studies i see cited refer to low effort, low intensity cardio.

I recall a lot of studies that centered around swimming not being an effective means of weight loss. They would do these studies taking untrained swimmers and throw them in a pool and have them swim laps. (these people likely thought they were burning crazy calories). None of them would lose weight. However, where were the studies on trained swimmers. I was a competitive for 13 years (starting at age 5). I can tell you... swimming at an Athletes level... Varsity highschool... 3 hours a day.... you lost weight and added muscle.... The studies just proved that meandering exercises dont do much....

crisanderson27

Here's my N=1 example.

Went from 210lbs to 154lbs in 9 months. Calorie controlled diet with approximately 150g protein averaged for day. Exercise choices was jogging, boxing & some bodyweight resistance exercise.

I went from fat to skinny fat. I know I lost a LOT of LBM. (no dexa scans or anything but by the end I could only bench 110lbs 1rm, which I previously did sets of 10 of) If I had my choice again, I would have done it slower and included resistance training from the start.

So for me, cardio only (even though I did do some other resistance training) definitely resulted in a large loss of LBM. I really wish I had a pic of me when I was twig skinny fat but unsurprisingly, not many photos taken in that time period

Boxing is resistance training which is great for muscle retention, so it sounds like it may not have been the absence of weight training that caused you to lose LBM, but more likely, overworking yourself in your cardio sessions combined with a calorie deficit.

I use boxing (100lb heavy bag) as my ONLY form of cardio (except the 4 minute tabata rowing session for warmup before lifting) lol.

Glucocorticoid

The reason you see that so many posts on MFP telling us that we will lose muscle if we do cardio only is because there is a large MFP population that comes to these forums from bodybuilding.com and/or other body building sites. You can even see the same catch phrases in many of their posts.

Of course you can keep muscle with cardio only. Muscles that are being worked regularly do not whither away, no matter how you work them.

Do you honestly think it's this simplistic? So people just lift weights for fun while in a deficit?

An hour of low intensity cardio won't usually cause problems, but let's take it to another extreme - three hours of high intensity cardio, done multiple times a week. As you go to a higher and higher states of intensities, you tend to recruit more type 2 muscle fibers while sending an "endurance signal" - this means the fibers need to adapt to the signal, which means becoming smaller. Combine that with a caloric deficit, and low protein intake, and this is bad news. Vaguely speaking, in that situation there is a higher likelihood of muscle loss, but even that will depend on various factors - to name some:
1. How overfat the individual is
2. Around workout nutrition and total daily caloric/macro intake
3. The rest of the training program (looking at frequency, volume, and intensity).
4. Genetics/gender
5. Other factors I'm overlooking at the moment

Of course, things get further complicated with the newbie effect. And when people are actually losing weight, even in the cases of muscle loss, the muscles hiding behind the fat become more apparent due to the accompanied fat loss, giving a more "toned" look, which adds on to the confusion. But none of this changes what I described above.

secretlobster

How is boxing resistance training?

Okay, my phrasing is wrong. Boxing is not resistance training in the way that weight training is, but it would be false to count it as a pure cardio workout that does nothing for your muscle conditioning. I built muscle JUST through boxing.

The problem with a lot of arguments here is that people who are claiming to have lost muscle mass doing cardio have lost SIGNIFICANT amounts of weight on a calorie deficit. You're not going to be able to maintain your current musculature if you're consuming fuel for a smaller person, no matter how much fat you lose in the process.

belgerian

Agreed to many variables to make a generalized statement. If you have low body fat to begin with like less than 6 percent than yes if you have a deficit you wil. Now if you were like me about 100 lbs overweight or morbidly obese or close to it than no I did just primarly cardio running consumed between 1600 and 2000 cal and the weight just melted off my runs were 1 hour to 1.5 hours today I still run 8 miles 5-6X a week. I am now gearing towards some form of resistance training. My legs are very toned now my upper boddy well still some work to do. Oh yea and I just ate whole foods mainly oatmeal for breakfeast, fruits and veggies and yogurt for lunch and something light for dinner. Few light snacks here and there apple,yougurt, almonds, veggies cheese sticks. And now I run outside fairly hilly area I might add so the 8 mile run if you were to level it out might be closer to a 10 mile on a level elevation. I also keep my arms up and my abs tightned while running. Dont get me wrong I think strenght training is important and it is something I need to add to my overall fitness plans I just have not yet.

Abells

I would like to see some scientific proof that you'll lose lean mass or become "skinny fat" by just doing cardio. Honestly, I haven't lifted weights since my early 20's. I've run, done yoga, done martial arts for years... I had a DEXA scan done in 2004 at 29 years of age that showed I have 120 lbs of lean mass and I had one done a few weeks ago that showed the same 120 lbs of lean mass. I haven't lifted a single weight in that time and my diet has been all over the board, two pregnancies... not to mention 8 years have passed.

So... why is it that people are told not to do cardio only? If you already have a decent muscle base, why not just burn off the fat? I don't understand. It seems pretty hard to lose muscle... there was a time I wanted to.

You've just stated that you do yoga (static strength resistance training), martial arts (involves explosive strikes and kicks which is anaerobic and considered resistance training). So you JUST haven't been doing cardio only.
And lean mass doesn't ALWAYS mean muscle. You can get higher density in your bones, organs can gain mass etc.

But there have been studies done that show if protein balance is insufficient, muscle breakdown occurs.

Not much of a problem for the average runner of course - a jog around the block or even a 5k is not the same as a distance runner in training who does a half-marathon every day, and sprinters probably come under the strength training header since they're doing brief spurts of anaerobic activity.

Cyclists however can easily wind up with elevated protein breakdown - good thing you guys tend to drink lots of sugar water (sports drink). Insulin inhibits the breakdown of muscle protein...

And you do want to replace the glycogen stores pretty much immediately for optimal sports performance(Sports Med; 21(1), 7-17, 1996.) - it does make a difference for both us lifters and you endurance guys.

Plus, if glycogen stores remain remain low, muscle protein breakdown can result and lead to loss of muscle mass (Journal of Applied Physiology; 48, 624-629, 1980) - again not neccesarily a concern for the once-around-the-block amateur, but for the long distance/long duration crowd who spend hours on the elliptical, definitely.


A.C.E. Certified Personal Trainer/Group Fitness Instructor
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 28+ years and have studied kinesiology and nutrition

^ this guy

Klem4

Interesting, will read more later!

pennybelle

bump

magerum

I dont have time to provide links and such but I can tell you this. I lost 160 lbs over the last year with just diet and cardio. My bench max went from 315lbs to 170lbs. Tell me that's not loosing lean body mass.

What were you eating? How much protein? Taking a year long break from lifting(regardless of diet) will cause strength loss.......

I was in heavy deficit for the year. For the first 7 months it was a regular 3000 calorie a day deficit. I was only eating about 70 - 80 g of protein daily. It was all in the name of rapid weight loss, which worked. I'm currently bulking to try and regain some strength. My only regret is not hitting the bench at all over the last year. I've seen some nice newbie gains the last 3 weeks though, kinda' starting all over. Just this time my body fat % is optimal! It's a marathon, not a sprint right?

I do miss the strength though

-M

bcattoes

The reason you see that so many posts on MFP telling us that we will lose muscle if we do cardio only is because there is a large MFP population that comes to these forums from bodybuilding.com and/or other body building sites. You can even see the same catch phrases in many of their posts.

Of course you can keep muscle with cardio only. Muscles that are being worked regularly do not whither away, no matter how you work them.

Do you honestly think it's this simplistic? So people just lift weights for fun while in a deficit?

An hour of low intensity cardio won't usually cause problems, but let's take it to another extreme - three hours of high intensity cardio, done multiple times a week. As you go to a higher and higher states of intensities, you tend to recruit more type 2 muscle fibers while sending an "endurance signal" - this means the fibers need to adapt to the signal, which means becoming smaller. Combine that with a caloric deficit, and low protein intake, and this is bad news. Vaguely speaking, in that situation there is a higher likelihood of muscle loss, but even that will depend on various factors - to name some:
1. How overfat the individual is
2. Around workout nutrition and total daily caloric/macro intake
3. The rest of the training program (looking at frequency, volume, and intensity).
4. Genetics/gender
5. Other factors I'm overlooking at the moment

Of course, things get further complicated with the newbie effect. And when people are actually losing weight, even in the cases of muscle loss, the muscles hiding behind the fat become more apparent due to the accompanied fat loss, giving a more "toned" look, which adds on to the confusion. But none of this changes what I described above.

Yes, you can overdo cardio and eat a bad diet. You can also keep LBM with cardio only IF done properly and while eating a proper diet? Does that make it all better?