Is 100 lbs. 'lean body mass' normal?
 

If there are any fitness geeks in this forum, I've got a question for you.

I have one of those Tanita scales that estimates your body fat percentage as well as telling your weight. As I consider the body fat issue, I wonder what the normal range of 'lean mass' (non-fat weight) is for me.

My calculations suggest that I've got roughly 100 lbs. of non-fat weight (and more fat weight than I'd like on top of that of course). For a woman of medium build, about 5'4", is that 100 lbs. in the ballpark of normal, or am I light on lean mass?

(One reason I ask this is that probably like a lot of people here, I've done a lot of dieting in the past and heard plenty about how that can catabolize lean tissue too.)

Going for a protein shake now... :)

cbcb, it is true that a history of yo-yo dieting, particularly low fat dieting, can result in lean mass being lost. If this is the case for you, then 100 lbs of lean mass could be realistic. Keep in mind that those scales can be off by a few % points, and that factors such as hydration and time of day will influence the reading you get (try stepping on the scale before and aftere a litre of water to test this).

Eating LC, specifically eating sufficient calories and adequate protein, will go a long way to sparing muscle loss. Lifting weights will take that even further. If you're new to lifting you can expect to gain some lean mass rather quickly, as well.

Adding just 10 lbs of lean mass can increase your resting metabolism by close to 500 calories a day - something not unheard of over the course of a year.

HTH
Nat

You must understand that hose scales or even calipers, can not really measure correctly the % body fat...
What these scales can do is measure progress over time, and even that is kinda iffy.. These scales use electrical resistance of the body and the theory goes that the more fat you have, the more water you store in it, the lower the electrical resistance of your body... It is not accurate.. measuring before or after exercising, or before or after a shower can skew the results significantly..


The only accurate absolute measurement of of % body fat, is done by immersion in water, and comparing the amount of water displaced with you weight.. (think Archimedes)..

So, I would not get too excited about the numbers this scales show.. You could use it to measure progress, but even for that it is not that great...

Thanks. What is a normal range of actual lean body mass for a medium-frame female about 5'4"?

cbcb, LBM will vary from individual to individual, just as the right weight for each person of the same height will. A general rule of thumb that is used is 100 lbs of weight for 5 feet, and 5 lbs for every inch added to that. This is body weight, not lean mass, however.

If you assume a standard BF% of 25 (which is considered average) then the LBM of a 5'4" woman, using the guideline above (body weight of 120 lbs) would be roughly 90 lbs. with 30 lbs of fat.

Increasing LBM and consequently decreasing BF would mean you could weigh more and occupy less space (i.e. wear a smaller size) as muscle has roughly 1/3 less the volume of fat per pound.

To give you an example - when I weigh 155 lbs I can wear a size 6, all thanks to 138 lbs of LBM.

HTH
Nat

Thanks very much - quite helpful! :)

hydrostatic
 

Hydrostatic (immersion in water) is not at all fun.

Calipers are a cheaper, convenient, and more "user friendly" option ...

Why is it "not fun"? I've been thinking about getting it done (if I could find a place, that is).

Wanda

I'll wager it's more fun than the one, truly accurate method of measuing lean mass ;)




Autopsy :lol:

Nat

Hyrdostatic isn't fun because while you are being dunked, you have to get as much air out of your lungs as possible, all the air out of your bathing suit, and all ofthe air bubbles out of your body hair for it to be an accurate measure ...

And they usually do it 3 times ...

I am satisfied using calipers.

Nat ... Too funny.

Trainerday, I wondered if that was what you were talking about. I'm a bit clausterphobic so I'll have to think about this.

Nat, :lol: Kinda useless to know at that point, huh?

Wanda

I recently saw a review of scales on TV.They said the ones that estimate fat% are inaccurate.

www.mybodycomp.com can do a body fat estimate from your weight and several body measurements. Some day when I get a tape measure I am going to do this.

cbcb-- this is just my 2cents worth.... There is a formula in the Protein Power book (by Dr.'s Dan and Mary Eades). This tells you your BF% (obviously not as accurate as the dunk method, but a good close estimate). You can also find out your LBMass as well and they take it to the next level of calculating your protein requirements to maintain that LBM. There is also a chart in their book on HEALTHY bodyfat% for all different age groups (men and women). If you don't have the book and would like me to figure it out for you, let me know.
Incidentally, the last time I figured out my own LBM (I am 5'3.5"), it was 109.

Carol