skeletal muscle increasing but muscle mass decreasing?

GirlWithCookies
GirlWithCookies Posts: 138 Member
in Health and Weight Loss
Hi, all. Wasn't sure where exactly to post this. I've been using the Renpho body composition scale since June. I really like it, but I'm confused about one thing: My skeletal muscle is increasing while my muscle mass and fat-free body weight are decreasing. This make me think that I'm losing muscle instead of just fat.

Basically, should I be concerned about this? I'm not looking to get ripped or anything, but I don't want to lose muscle. What should I do to prevent this?

Skeletal muscle has gone from 35.6 to 37.2, muscle mass has gone from 96.6 to 95.2, and fat-free body weight has gone from 102.6 to 101.4.

Sorry if this is a questions already answered in the forums. I couldn't find one about this specifically, but if there is, feel free to point me to it.

Replies

  • Lietchi
    Lietchi Posts: 6,787 Member
    What are the units of these measurements, are they all in lbs or is the skeletal muscle a percentage?

    Aside from that, body composition scales are not reliable. Different levels of hydration for example can give you different numbers.
  • GirlWithCookies
    GirlWithCookies Posts: 138 Member
    @Lietchi Whoops, units would have helped. Skeletal muscle is percent, muscle mass and fat-free body weight are pounds.

    @janejellyroll So a couple pounds of muscle mass "loss" in three months is negligible overall? I know body comp scales aren't necessarily reliable or accurate, I just really have no idea if I should even pay attention to muscle mass.
  • heybales
    heybales Posts: 18,842 Member
    edited September 2020
    Considering if you could present the exactly same hydrated body to the scale (which you likely won't), and it was actually a well tested scale for accuracy or at least consistency (which not all are), the best you could hope for would be 5% accuracy.

    So looking at your figures, is there really enough change to show strangeness - or still within the bounds of expected error rate?

    And that's just BF%, the other calculations are even less accurate.
    All the values start as % too, math is merely done for display.
  • janejellyroll
    janejellyroll Posts: 25,763 Member
    GirlWithCookies wrote: »
    @Lietchi Whoops, units would have helped. Skeletal muscle is percent, muscle mass and fat-free body weight are pounds.

    @janejellyroll So a couple pounds of muscle mass "loss" in three months is negligible overall? I know body comp scales aren't necessarily reliable or accurate, I just really have no idea if I should even pay attention to muscle mass.

    Instead of focusing on the potentially unreliable results from your scale, I would instead focus on the known things you can do to reduce the amount of muscle lost when losing weight. As mentioned above: resistance training, sufficient protein, and a reasonable rate of loss are what help preserve muscle during weight loss.
  • GirlWithCookies
    GirlWithCookies Posts: 138 Member
    Got it — resistance training and sufficient protein. Thanks, everyone. Good thing I posted before I let unfounded worry take over!
  • heybales
    heybales Posts: 18,842 Member
    Forgot reasonable rate of loss.

    Interesting you left that off.

    Do you know what that might be in your case?
  • GirlWithCookies
    GirlWithCookies Posts: 138 Member
    @heybales Sorry if you thought that was rude. I wasn't ignoring it, it's just something I already knew and have been doing.
  • heybales
    heybales Posts: 18,842 Member
    Didn't think it was rude at all - just interesting it wasn't mentioned.

    Usually most see reasonable or slow rate and don't want to do that, or have no idea what that means but think 2lb weekly must be slow compared to Biggest Loser rate, but it's really not in most cases.

    So just wanted to confirm you got the 3 legs to stand on for retaining muscle mass.
  • gewel321
    gewel321 Posts: 718 Member
    How are you liking your scale? I ordered mine a few weeks ago and find it highly unreliable. My daily weights (done the same time and dress and all that stuff) have fluctuated sometimes more than 5lbs a day. My old scale has been steady and moving down or up at a reasonable rate. The first day I got on it my old scale said 203 the new one said 195. I am still using my old one for my tracking but it is interesting to see all the information the Renpho one gives.
  • GirlWithCookies
    GirlWithCookies Posts: 138 Member
    @gewel321 I like it. I bought it mostly to see BMI vs. body fat percentage. I know a lot of people say these types of scales are unreliable, but I can't afford to go a specialty clinic that will take body comp measurements. As for weight, I only weigh myself once a week, so I can't comment on daily fluctuations. For this week's weigh-in I'll try both the Renpho and my old basic scale and see how different they are.
  • rjleskovec
    rjleskovec Posts: 1 Member
    edited March 2021
    I have a Renpho scale as well and see the same thing. Weighing the same time every day when I wake up. Skeletal muscle increasing while muscle mass decreasing. Then randomly with maintaining the same eating regimen and water intake I'll get a day where I'm up 3 lbs and had the same calories, activity and water as days before. THen the next day It's back down 4 lbs. Weird. overall i like the scale, but I think it's a little screwy and the body fat % is marginal.
  • tiffanyleegross
    tiffanyleegross Posts: 1 Member
    I have a similar situation if anyone wants to chime in

    Renpho scale

    Started orange theory fitness in oct of 2020

    Skeletal muscle percent trending up
    Oct 35.9%
    Today 37.6%

    Muscle mass trending down
    Oct 109.4 lbs
    Today 108 lbs

    Fat free body weight
    October 116.4
    Today 114.6

    Is this normal? I’m down about 10 pounds since starting exercising.

    I did get the chance to compare to the in body scan and the results were very similar.
  • PAV8888
    PAV8888 Posts: 14,223 Member
    edited March 2021
    tiffanyleegross wrote: »
    I have a similar situation if anyone wants to chime in

    Renpho scale

    Started orange theory fitness in oct of 2020

    Skeletal muscle percent trending up
    Oct 35.9%
    Today 37.6%

    Muscle mass trending down
    Oct 109.4 lbs
    Today 108 lbs

    Fat free body weight
    October 116.4
    Today 114.6

    Is this normal? I’m down about 10 pounds since starting exercising.

    I did get the chance to compare to the in body scan and the results were very similar.

    So you're 10lbs down of which, roughly, 8lbs were everything that is NOT fat free (i.e. 8lbs were fat) and 2lbs were non fat (i.e. fat free body weight)

    So your fat to lean mass loss ratio is 4:1....

    I'd call that pretty good.

    I would call anything below 2:1 a let's be a bit cautious and consider what we're doing here zone.

    But in spite of my personal concerns fat to lean mass loss ratios of 2:1, 1.5:1 and even 1:1 are results that are seen in weight loss studies and would be absolutely acceptable under the appropriate circumstances.

    Renpho (or any bioimpedence) margin of error remains quite vast. Vaster than the rest of the marginsyou mentioned

    I note that skeletal muscle increasing as a percentage of total remaining weight would also normally be interpreted as a good result... And would be an expected result since you're purported to be currently losing four times as much fat as anything else
  • westrich20940
    westrich20940 Posts: 913 Member
    gewel321 wrote: »
    How are you liking your scale? I ordered mine a few weeks ago and find it highly unreliable. My daily weights (done the same time and dress and all that stuff) have fluctuated sometimes more than 5lbs a day. My old scale has been steady and moving down or up at a reasonable rate. The first day I got on it my old scale said 203 the new one said 195. I am still using my old one for my tracking but it is interesting to see all the information the Renpho one gives.


    I use the Renphro one bc my roommate got it and told me I could use it. I've used it to track my weight and when I go over to visit with my parents, when I think about it, I also weigh myself on their scale (a regular digital one)...and they seem to be fairly equal for weight.

    I know that the additional stats it gives may be inaccurate but I don't use them for anything other than maybe looking at my body fat % -- and in general I just wanted to see the trends and it lets you look at a visual graph - which is nice to see if you feel like the numbers aren't going down at least you can SEE the line going down.

    So...it's also possible that your 'old' scale isn't valid too. I will have to think about it if I'm at some other location where I can check my weight on a 3rd scale and see if it's more/less the same.

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