Why am I burning muscle and not fat?

jtintx
jtintx Posts: 445 Member
edited September 2024 in Health and Weight Loss
I’ve got a problem that I hope someone can help me with. I had a body fat% analysis done awhile back using the Bod Pod and had another one done yesterday. It shows that I’ve lost 7 lbs but it was all muscle! I still have the same number of pounds of fat as I did previously! I’m obviously doing something wrong.

I’m training for a triathlon so I swim, bike and run. I work out 6 or 7 days a week, usually once in the morning and again in the evening. I take a rest day when I feel like I’m getting fatigued. My bike rides are pretty intense but my running is usually at an easy pace (heart rate between 75-85% MHR). I just recently started to do some weight lifting because I noticed my arms seem to be getting “soft”.

I looked back at my food diary and noticed that in the last 90 days 68 days my NET calories were 1500 or above and 22 days were 500 or below.

What am I doing wrong? Why am I burning muscle and not fat?

Replies

  • schnarfo
    schnarfo Posts: 764 Member
    im not an expert but I think that you possibly need more food. when our bodies dont have enough food for fuel it starts to break down muscle to get the energy it needs. Cardio will just continue to burn the muscle away unless your trying to stop the effects by strength training. Then you will need to make sure you have enough protein in your diet to ensure you are repairing those muscles and helping them grow.
  • jrich1
    jrich1 Posts: 2,408 Member
    I agree more food... 22 days at 500 calories are below net.
  • ltf304
    ltf304 Posts: 132 Member
    I'm not an expert either but if you're doing a lot of cardio and just started strength training then thats the reason. Cardio doesn't necessarily build muscle but strength training does. I would try to add more strength training in your workouts and see if that helps. Also, strength training is VERY important to prevent injury, especially since you're running and biking.
  • yanicka
    yanicka Posts: 1,004 Member
    You really need to eat more. Since you are training so intensly, I would suggest stopping with the caliric defficit. You are hurting your metabolism. Eat more....you will probably notice a weight gain at first until your body stop freaking out. I hope someone more knowlegable will answer your questions
  • diembroadhurst
    diembroadhurst Posts: 62
    I would guess that your metabolism has slowed down and your body is burning up muscle for energy. I would increase your calorie intake to boost metabolism by eating 5-6 meals through the day - make sure you eat protein in each meal. Increase by 100-200 every couple fo days until you are at the best level for your body and the exercise you are doing.
  • Mateo1985
    Mateo1985 Posts: 153
    Our bodies are survival machines. Because of your intense workout and low calorie intake it's trying to preserve fat and decrease the muscle mass that burning the stored fat. If you're exercising as much as you do your calorie intake should be around 2000 cal a day at the minimum. That way you'll still be lossing fat and maintaining the muscle mass. So either stop working out at least to an extend or inscrease your calorie intake. I'd go with the second one.

    Hope it helps.
  • beerbomber
    beerbomber Posts: 184 Member
    Well it is actually not simple to explainbut can try. It makes sense that your losing muscle if your working out very hard because your body needs protein it breaks it down into amino acids which rebuild all your muscle and such, if your body is not getting enough protein then it has to take it from your body which will be your muscle. Kind of a very simple way to explain it and little more goes into it than that but simple solution add more protein to your diet and make sure your eating enough complex carbs
  • Mike523
    Mike523 Posts: 393 Member
    I think you partially diagnosed your problem already, when you said your arms were getting soft and you added weight lifting. Too much cardio and no heavy weight lifting can cause your body to feed on muscle. Especially if you're not getting enough food. Keep your net calories up where they need to be EVERY DAY, weight train 3 days per week with heavy weights (you need to USE your muscles if you want to keep them), and do less cardio (3-4 days per week).
  • RCKT82
    RCKT82 Posts: 409 Member
    If your calorie deficit is too high your body will go into muscle atrophy to try to preserve the fat because it thinks you're headed for a famine, so it's trying to protect itself. Also if your heart rate is too high during your workout outs, you'll burn too many calories in such a short time and your body cannot burn enough fat to sustain that lost, so you'll start burning muscle also. I would try to lower your workout intensity, do more strength training, and keep a careful eye on your calorie deficit. This is all in my opinion... and is only based on what I found to work for me.
  • Kimber1012001
    Kimber1012001 Posts: 30 Member
    hey there!

    performing only cardio exercises will make you lose muscle for sure. After about 35 mins most of your glucose stores are expended and the body looks to the muscles to generate fuel to sustain the workout., hence the muscle loss. You need to build up the muscles with weight both to improve the efficiency of the cardio routine (stronger muscles = able to work out longer and harder) as well as to slow down the breaking-down process.

    I'd personally aim for some smaller more intense cardio workouts (HITT) like 2x wk to improve strength/speed of ure cardio capacity and add some circuit training 3x a week, this is when u constantly mix up the routine w/ very little breaks between sets (just Google 'circuit training' and you'll find loads of info about making a program) and then that slower swimming day to round it all out.

    Start slow though, don't expect to do all this at once intervals are a lot harder than long term endurance because you're body is constantly changing motion and pattern within the routine! I hope it helps..!
  • shuvhead
    shuvhead Posts: 1
    I have been working with a trainer for months now and the first thing he explained was nutrition. This one is simple, when you are working out your body needs vitamins, minerals and nutrients...what has more of that? Muscle or fat? Muscle of course so your body will burn muscle and store fat. Try to eat more lean protein and complex carbs and also make sure to take a good multi vitamin. I dropped alot of weight but gained about 27lbs of lean muscle mass and it was amazing how lean my body got. I take a multi vitamin fish oil and calcium everyday and I eat a ton of veggies fruits and nuts...the greener the vegetables the better. I hope this helps, the trainer I have has really helped me so I hope to pass it on. Lots of good info on this site
  • EA1604
    EA1604 Posts: 61 Member
    Eat more protein! That is what helps your muscle develop.
  • Jxnsmma
    Jxnsmma Posts: 919 Member
    I think you need to add some more protein to your diet. Easiest way is to start drinking a protein shake right after your workout. A good one I use is 1/3 cup of low fat greek yogurt, 1/2 a banana, 1/2 cup skim milk, 1tbsp ground flax seed and 1 serving of protein powder. Look for one that is low in sugars. This shake will add over 300 calories, most of which is lean protien, to your diet. If you dont eat enough protein, your body burns it instead of fat. Silly bodies... :) Good luck!
  • dlaplume2
    dlaplume2 Posts: 1,658 Member
    You really need to eat more. Since you are training so intensly, I would suggest stopping with the caliric defficit. You are hurting your metabolism. Eat more....you will probably notice a weight gain at first until your body stop freaking out. I hope someone more knowlegable will answer your questions
    I agree. I would stop with the calorie deficit, make sure you are increasing protien. You do need extra protien to build muscle.
  • MrsWibbly
    MrsWibbly Posts: 415 Member
    My understanding is on days when you don't eat enough your body will burn muscle and fat, but on days when you eat too much your body will add fat. So I think the trick is to keep the net calories steady. MFP recommends always eating your exercise calories (I assume to prevent muscle being burnt) and I tend to agree with others that eating protein and strength training will help build muscles.

    Hope this helps
  • hroush
    hroush Posts: 2,073 Member
    Another thing that I don't think was really touched is that you don't have much fat left, judging by only having 13 more pounds to lose in your ticker. This will also make it harder to finish off those last fat deposits. But as the others said, long, intense cardio will burn muscle (I discovered the same thing). You need to increase your food intake and especially your protein. If you want that muscle back and burn off the last of the fat, you need to start strength training. Heavy weights are the way to go here.
  • natskedat
    natskedat Posts: 570 Member
    I agree with everything that everybody said. I trained for a triathlon through April. Take a look at my diary in April. I didn't lose any weight (I wasn't trying) and I gained muscle. I ate a LOT. Tri training takes a lot of energy, and the recovery is more intense too. Even on off days I was eating upwards of 2700-3000 calories. Your metabolism is going to be off the charts! I actually don't recommend a huge calorie deficit when you're trianing as intensely as you are. Lots of lean protein and complex carbs are the keys to muscle building and strength.
  • Mommawarrior
    Mommawarrior Posts: 897 Member
    Strength train and cardio both need to be done. 1 without the other is counterproductive. Also, exercising without eating enough is too.

    On a side note...
    RCKT82, everytime I see your before and after picture I just want to go run 40 miles and lift 600 lbs several times!
  • DaddyMantz
    DaddyMantz Posts: 145 Member
    There are some good sites that help you with your diet to lose fat and retain muscle. Tom Venuto is one expert. I recommend that you read his blog and possibly buy one of his books. I personally lost 40 lbs of fat and muscle between sept 2010 and Jan 2011. Then I got Tom's book, followed it, and lost 6% bodyfat while gaining back 90% of my lost muscle in about 2 months.

    It's probably extra difficult with the extreme levels of cardio but it just means you have to eat a LOT.
  • wewon
    wewon Posts: 838 Member
    Man this is a good question.

    When I first came to MFP I was training for a half marathon, primarily as a motivation to stay in shape and I noticed some of the same things. Working out 6 days/week, mostly cardio, but very light weight lifting.

    My weight was staying the same although I was losing inches.

    Since the half I have started more moderate runs and have amped up the weights. I started seeing the scale go down this week.
  • RCKT82
    RCKT82 Posts: 409 Member
    Strength train and cardio both need to be done. 1 without the other is counterproductive. Also, exercising without eating enough is too.

    On a side note...
    RCKT82, everytime I see your before and after picture I just want to go run 40 miles and lift 600 lbs several times!

    Thanks Momma!! Everytime someone comments on my transformation I want to go run some more and lift more! Thanks for the motivation!!!
  • jtintx
    jtintx Posts: 445 Member
    Ok, the consensus is that I need to eat more and especially more protein. But I still don't understand why I didn't lose a single pound of fat when I've been doing so much long, slow running. How can that NOT burn fat? I'm in the "fat burning zone". I admit that I rarely reach my protein goal for the day...but I'm almost always over on the carb goal. I know I need the carbs to fuel my workouts. Why isn't my body using excess fat for fuel instead of muscle? Geez, I'm really bummed about losing so much muscle (for me).

    BTW, RCKT82 your progress is phenomenal!!!

    Edited to add a another question.
  • jtintx
    jtintx Posts: 445 Member
    If your calorie deficit is too high your body will go into muscle atrophy to try to preserve the fat because it thinks you're headed for a famine, so it's trying to protect itself. Also if your heart rate is too high during your workout outs, you'll burn too many calories in such a short time and your body cannot burn enough fat to sustain that lost, so you'll start burning muscle also. I would try to lower your workout intensity, do more strength training, and keep a careful eye on your calorie deficit. This is all in my opinion... and is only based on what I found to work for me.
    Oops...guess I missed this or didn't absorb it at first. I think this answers my question about why muscle instead of fat. But I still can't see why I lost absolutely NO fat at all.
  • RCKT82
    RCKT82 Posts: 409 Member
    You are probably burning fat too... but the rate at which you're losing muscle compared to fat is much higher. So if you take %BF reading, it's going to be based on how much fat your body has stored compared to your overall weight. It won't be based on how much fat you have stored compared to your muscle mass. You're %BF won't change much in this case even if you are burning a massive amount of calories and losing weight because of the way %BF is measured against overall weight.
  • RCKT82
    RCKT82 Posts: 409 Member
    In addition... Your volume of fat will be lower than what it was before, but like I mentioned in my last comment. your reading is based on your current overall weight.
  • RCKT82
    RCKT82 Posts: 409 Member
    sorry... double post
  • jtintx
    jtintx Posts: 445 Member
    You are probably burning fat too... but the rate at which you're losing muscle compared to fat is much higher. So if you take %BF reading, it's going to be based on how much fat your body has stored compared to your overall weight. It won't be based on how much fat you have stored compared to your muscle mass. You're %BF won't change much in this case even if you are burning a massive amount of calories and losing weight because of the way %BF is measured against overall weight.
    I wish this were true but it doens't appear to be. Might as well give the numbers.

    Previous test: Weight: 148.3 lbs. Lean weight: 105.3 lbs (71%) Fat: 43.0 lbs (29%)
    Current test: Weight: 141.7 lbs. Lean weight: 98.7 lbs (69.6%) Fat: 43.0 lbs (30.4%)
    My actual body fat % has increased just a bit. But after all this cardio I still have 43 lbs of fat that just won't seem to go away. My body is burning muscle instead and I have plenty of body fat for it to use. I'd like to get to 20% body fat. That would put me in the "Lean" catagory. (That would be about the equiv. of 10% for men).
  • Mateo1985
    Mateo1985 Posts: 153
    RCKT82

    Awesome job man!!!! Unbelievable progress!!!
  • RCKT82
    RCKT82 Posts: 409 Member
    I wish this were true but it doens't appear to be. Might as well give the numbers.

    Previous test: Weight: 148.3 lbs. Lean weight: 105.3 lbs (71%) Fat: 43.0 lbs (29%)
    Current test: Weight: 141.7 lbs. Lean weight: 98.7 lbs (69.6%) Fat: 43.0 lbs (30.4%)
    My actual body fat % has increased just a bit. But after all this cardio I still have 43 lbs of fat that just won't seem to go away. My body is burning muscle instead and I have plenty of body fat for it to use. I'd like to get to 20% body fat. That would put me in the "Lean" catagory. (That would be about the equiv. of 10% for men).

    With the little amount of weight loss and with all the cardio you've been doing, I would lean towards questioning the accuracy of the bodpod. I do know that it's harder to get a %BF reading off of weight lifters and athletes. Granted most bodpod readings are pretty accurate; there's always room for discrepancies and precision depending on each test. But your dilemna is way beyond my knowledge for determining what could possibly the actual cause. It could be the bod pod or could be completely something else. Sorry, wish I could have helped answer your question. But unfortunately I don't have any credentials or expertise on this, just the run of the mill info that I've read up online and on basic health books. Good luck, keep us informed if you find out what's going on.
  • MrsWibbly
    MrsWibbly Posts: 415 Member

    I wish this were true but it doens't appear to be. Might as well give the numbers.

    Previous test: Weight: 148.3 lbs. Lean weight: 105.3 lbs (71%) Fat: 43.0 lbs (29%)
    Current test: Weight: 141.7 lbs. Lean weight: 98.7 lbs (69.6%) Fat: 43.0 lbs (30.4%)
    My actual body fat % has increased just a bit. But after all this cardio I still have 43 lbs of fat that just won't seem to go away. My body is burning muscle instead and I have plenty of body fat for it to use. I'd like to get to 20% body fat. That would put me in the "Lean" catagory. (That would be about the equiv. of 10% for men).

    I saw something in another topic that might explain this... (I will try and summarise what I understood)

    Starvation mode: when you starve your body it triggers something that means that next time you eat instead of using this as current fuel your body will store a higher proportion as fat. So basically if you don't keep your net calories consistent from one day to the next then you will actually increase your body fat %.

    Also I remember reading a theory on long term and short term fat stores. Short term fat stores are inside the muscle tissue and are easy for your body to access and burn. Long term fat stores (the wobbly bits and the internal stuff) need to be moved to the muscles to be able to use them. In order to redistribute fat from long term stores to the muscles (this is where my memory gets fuzzy) I think you need to do strength training to work the muscles hard and rest in between. I will try and look this up.
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