How to identify muscle loss

[SuppKnight]

If you have BF% and your weight you can determine your lean mass weight and your fat weight. If you lose 10 lbs, for example, and calculate your BF%, you can know how much lean mass you lost as well, if any.

However, lean mass does not equal muscle on a 1:1 ratio. In that case, how can you calculate if there is muscle loss?

Example:

200 lbs at 20% BF = 40 lbs of fat, 160 lbs of LM

Loses 10 lbs and 2% BF

Becomes

190 lbs at 18% BF = 34 lbs of fat, 156 lbs of LM


Here, the subject los 6 lbs of fat and 4lbs of LM, but since LM is not equal to muscle on a 1:1 ratio, did he lose any muscle? If so, how much and what formula should be used?

 

[t-bone2]

Is this what you mean by "LM is not equal to muscle on a 1:1 ratio?"

Since Lean Body Mass is made up of the skeleton, skin, visceral organs, plasma proteins and skeletal muscle, you could assume that these have little variation during body recomposition, with the exception of muscle.

Thus in you example, he lost 4 lbs of LBM (or muscle) calculated as:

Starting LBM - Ending LBM

 

[SuppKnight]

Is this what you mean by "LM is not equal to muscle on a 1:1 ratio?"

Since Lean Body Mass is made up of the skeleton, skin, visceral organs, plasma proteins and skeletal muscle, you could assume that these have little variation during body recomposition, with the exception of muscle.

Thus in you example, he lost 4 lbs of LBM (or muscle) calculated as:

Starting LBM - Ending LBM

Well, if it was that easy, where would water go? Water is not fat, and it is not muscle, but it gets calculated into LBM, meaning the 4 lbs lost could be ALL water weight, or all muscle weight, depending on hydration levels, etc.

 

[t-bone2]

Ok, I see what you are asking. Protein makes up ~20% of muscle while the other ~80% is made up of glycogen, water, minerals, etc. You are asking what percent of the ~20% muscle is lost vs. what percent of the ~80% remainder of LBM is lost.

 

[SuppKnight]

Ok, I see what you are asking. Protein makes up ~20% of muscle while the other ~80% is made up of glycogen, water, minerals, etc. You are asking what percent of the ~20% muscle is lost vs. what percent of the ~80% remainder of LBM is lost.

Yes, I think. Is there any way to know this? I'm guessing most of the loss will be water and others, then, since it is 80%, but is there anyway to know for sure?

 

[t-bone2]

I'm not aware of a noninvasive way to quantify the components of lean body mass.

There have been studies performed that have attempted to characterize gross tissue weights. One study estimated that skeletal muscle mass is ~25% of total body weight.

There are also studies that have looked at post-exercise muscle glycogen synthesis rates based on ingestion of various amounts of carbs.

I think that the best you could do is very generalized assumptions.

 

[SuppKnight]

I'm not aware of a noninvasive way to quantify the components of lean body mass.

There have been studies performed that have attempted to characterize gross tissue weights. One study estimated that skeletal muscle mass is ~25% of total body weight.

There are also studies that have looked at post-exercise muscle glycogen synthesis rates based on ingestion of various amounts of carbs.

I think that the best you could do is very generalized assumptions.

Ok, thanks for the input. So I guess I should just go by how I look (taking pics frequently and comparing them) to determine what amount of muscle, if any, is lost, and go from there.

 

[t-bone2]

A genericrule-of-thumb in the BB community has been that, if your lifts are dimishing (in intensity, not volume) you're overall strength is going down, thus you are losing muscle mass. This needs to be taken with a grain of salt, but it may be a useful starting point for what you are attempting to measure.

 

[SuppKnight]

A genericrule-of-thumb in the BB community has been that, if your lifts are dimishing (in intensity, not volume) you're overall strength is going down, thus you are losing muscle mass. This needs to be taken with a grain of salt, but it may be a useful starting point for what you are attempting to measure.

I always confuse intensity and volume.

Intensity = Maintaning the same level of power on every Rep; Volume = Amount of Reps; Am I right?

In that case, being on a CKD (like I am now), can cause losses in intensity as well, not because you're losing muscle, but because your energy level is down. If that's the case, it would be a bad measuring stick as well, no? Correct me if I'm wrong, and thanks for the input once again.

 

[t-bone2]

You are correct on both counts. When cutting, you are eating below normal maintenance levels so energy is reduced. The goal during that time is to maintain (as best possible) muscle while oxidizing fat. Reduce volume (reps), but attempt to maintain intensity in an effort to maintain strength. It is a fine line and, depending on how much fat mass you are attempting to lose, it is probable that strength will be impacted.

 

[SuppKnight]

You are correct on both counts. When cutting, you are eating below normal maintenance levels so energy is reduced. The goal during that time is to maintain (as best possible) muscle while oxidizing fat. Reduce volume (reps), but attempt to maintain intensity in an effort to maintain strength. It is a fine line and, depending on how much fat mass you are attempting to lose, it is probable that strength will be impacted.

Ok, I got it. Thanks. You've been truly helpful.