BMI..and why it should not be mentioned on ST

Triathlon Forum
1

Dearest fellow athletes , friends and loved ones.

Can we please refrain from using BMI on ST.

BMI is a “general” measurement for the “masses” to have a common denominator to determine body fat.

As 220-age gives us “general” heart rate parameters for the “masses” to have a “general” idea as to what ranges to train in.

Not , by any means trying to sound elitist , but considering that the majority of us ,are dedicated to not only our sport , but the knowledge and wisdom behind it , I think those of you that use it should read a “touch” further.

Human beings are categorized into three body types , or a combination of those.

ECTOMORPH… Definitive “Hard Gainer” Delicate Built Body Flat Chest Fragile Lean Lightly Muscled Small Shouldered Takes Longer to Gain Muscle Thin

MESOMORPH… Athletic Hard Body Hourglass Shaped (Female) Rectangular Shaped (Male) Mature Muscle Mass Muscular Body Excellent Posture Gains Muscle Easily Gains Fat More Easily Than Ectomorphs Thick Skin

ENDOMORPH…
Soft Body Underdeveloped Muscles Round Physique Weight Loss is Difficult Gains Muscle Easily Like the Mesomorph

Having said that , BMI does not take into body types. Additionally , muscle weighs more than fat.

For example:
Jim-Bob …stands 5"9 and weighs 185. He is a Mesomorph and has a history of lifting weights and doing a lot of cardio. Coincidentally, he maintains low -body fat and is very muscular.

Bartholemew…stands 5"9 and weighs 185. He is an Ectomorph. He has a history of alcoholism and does not exercise. Coincidentally , he is overweight and has little muscle mass.

They both have a body mass index ( BMI ) of 27.3.

**BMI Categories: ** Underweight = <18.5 Normal weight = 18.5-24.9 Overweight = 25-29.9 Obesity = BMI of 30 or greater
Is Jim-Bob with his 27.3 BMI Overweight ?

Jim-Bob is not overweight , he is a Mesomorph.

Let’s try and keep this forum full of useful information and improve our knowledge base. Oh , and for the record I am a Mesomorph and my BMI is 23 :slight_smile:

Thank you.

Disclaimer: Being Canadian we use Metric , but for diplomatic reasons and this forum being based in the USA I will use the Imperial system.

2

“BMI is a “general” measurement for the “masses” to have a common denominator to determine body fat.”

I certainly agree that BMI does not provide an accurate measure of body fat, but this is not the intended used for BMI today. A few years back, definetly, but today BMI is used as a predictor for risk of cardiovascular disease. BMI has a much higher correlation with cardiovascular problems than body fat percentage.

So having a BMI of 29, 30, or 32, might not necessarily mean that the person is overweight, more than likely that person has higher risk for cardiovascular disease them somebody with a BMI of 23, 34. The problem is not with the measure itself but the use of the measure. The only measure that has been proven better then BMI for prediction of cardiovascular disease is waist/height, but this measure creates a large number of problems.

Having said that, if you want to really talk about body fat percentage measurement you need to talk about hydrostatic weighing or DEXA and really forget about everything else.

Tiago Barreira

3

I’ll agree with the other poster, BMI was created by the insurance industry to assess risk. not as a measure of body fat at all.

Also the 220-age for maximum heart rate has a standard deviation of about 8-10 beats I believe.

4

Oh come awwwwn… if we get rid of BMI discussions, whats next? People will stop discussing the benefits of Carbon vs. Aluminum… or DA vs. Ultegra… or …

Lets be honest… some masochist created BMI as a way to force everyone on athletic internet forums into rabid debates.

5

Its in use b/c its very easy to calculate, and like someone else said, can be a good predictor for CV risk, etc.

With BMI, there are exceptions- it just so happens that we’re sitting right in the middle of a community of exceptions, so it seems awful. For the masses its generally OK.

6

I think that’s the most words I’ve ever seen to not discuss something.

7

In week 1 of medical school we are trained to look at both BMI and waist diameter. Docs aren’t especially worried about a high BMI and a small waist (think Governator). They are worried about a high BMI and a >36inch waistline. I don’t remember the exact numbers (taking a few years off for basic science research), but that’s the gist of it. The scale is needed because overweight, obese, etc are codable diagnoses used for billing. I’m sure someone on this forum who is actually done with their med training can add more.

8

i think i am a mesomorph but i can’t tell for sure as it is covered in a thick rounded layer of fat! :slight_smile:

–

for me BMI is a bug i must bear… i pay extra health insurance on my mortgage because of in part my BMI score.
am i fat?.. hell yeah!,… but i am very fit and have lots of other factors that reduce my risk, but my argument with the assessor over the inadequacies of BMI fell on deaf ears.
it bugs me that i pay more than an ECTOMORPH who sits on his arse all day eating mcdonalds.

but… even though i am more endo than meso i can’t hide the fact that the fat is there because i ate too much… maybe others can eat more and still score well on the BMI but i can’t.

i am currently successfully reducing my BMI score, and when i get it low enough i am gonna shove my bluddy BMI score up the assessor’s ar$e

BMI might be a good marker for risk in general, but anything ‘in general’ has winners and losers. i am on the losing end, but i am determined now to turn around that ‘losing’ factor and get it to work for me in my weight loss goals.
the money i will save on my health insurance as a result will go towards the ‘milkywaye carbon bling fund’

9

I guess you haven’t seen the Governator lately. It appears he’s trying to balance out Skeletor, er, his wife.

Nonetheless, he does get credit for probably the best fat measurement method available to the common man: stand in a mirror and jump up and down. If it jiggles, it’s fat.

10

I recommend that we Modify the Body Mass Index and add a factor of waistline to the equation.
This will dramatically change the BMI results as I too am technically “Overweight” according to BMI, which is laughable.

11

I use BMI every single day of my life and will continue to use it. As a clinical dietitian, it is one of the easiest ways to classify risk as someone else has mentioned. Medicare/Medicaid use the BMIs found within our notes to either reimburse or not (these are folks with a BMI of <18.5 or >30).

Of course, as athletes and whatever-morphs one might be, BMI is still a good tool and something that everyone should at least be aware of. If you know that you have a BMI of 28 and are pure muscle then fine, good for you.

However, most Americans are are overweight or obese and are kids are following suit. They are obviously not athletes. And dare I say that even some on Slowtwitch are not necessary athletes in the physical sense.

And I don’t care how muscular you think that you are, if you have a BMI of 30 or more, you are obese.

12

I think BMI should be stricken from our vernacular…According to BMI, at 5’10, 205 I am obese, but I guess it is normal for obese folks to run 1:31 1/2 marathons and 3:30 marathons.

Even as a generalization it is grossly out of whack with the state and nature of an individual.

Bob

13

I use BMI every single day of my life and will continue to use it. As a clinical dietitian, it is one of the easiest ways to classify risk as someone else has mentioned. Medicare/Medicaid use the BMIs found within our notes to either reimburse or not (these are folks with a BMI of <18.5 or >30).

Of course, as athletes and whatever-morphs one might be, BMI is still a good tool and something that everyone should at least be aware of. If you know that you have a BMI of 28 and are pure muscle then fine, good for you.

However, most Americans are are overweight or obese and are kids are following suit. They are obviously not athletes. And dare I say that even some on Slowtwitch are not necessary athletes in the physical sense.

And I don’t care how muscular you think that you are, if you have a BMI of 30 or more, you are obese.
I completely disagree BMI is a horrible tool when dealing with any sort of athletic population. It was never intended to be used on that group. It is also very shaky when dealing with the elderly.

It is meant to be used on “Average” build people.

Being over 30 doesn’t make you obese, i have seen many Football players, male gymnasts, and weight lifters over 30, who were no where near obese. Are Donovan McNabb, Steve McNair, Daunte Culpepper, and Corey Dillon obese they’re all over 30.

It’s a good tool when dealing with your average person, if you’re dealing with people outside that body comp is the only way to go.

14

Imagine how quick you’d be if you got down to your recommended weight :wink:
.

15

My recommended weight is 178 or so…If I were that thin I think I might be a bag of bones.

Bob

16

“Professional football players are now more than twice as likely as Major League Baseball players to die before their 50th birthday, and medical experts say the culprit is probably differing body bulk.”

http://sports.espn.go.com/nfl/news/story?id=2313520

Call it bulk, call it muscle, call it whatever you want. If its affecting your lifespan, it can’t be all that great for you now can it?

17

Arnold had a BMI of 34 during contests…and he had what, 1-2% body fat or something?

But this all hinges on your definition of “obese”. Medterm.com defines it as:

Well above ones normal weight. A person has traditionally been considered to be obese if they are more than 20 percent over their ideal weight. That ideal weight must take into account the person’s height, age, sex, and build.

If you factor in Arnold’s build, I doubt we’d call him obese even though he is far heavier than his “ideal weight” (whatever that may be!).

18

I’m not a big fan of BMI, but you kinda picked a bad example. First off out of the entire population in the world, you picked the one person who has essentially won a contest for being a BMI outlier. Second BMI isn’t really supposed to be used to identify obese individuals, its supposed to be used to identify individuals prone to heart and other health problems. As I recall the Governator had open heart surgury fairly recently.

Styrrell

19

Getting back on topic…why BMI shouldn’t be mentioned on ST, I think it’s because fat people are really sensitive about things like BMI.

20

“First off out of the entire population in the world, you picked the one person who has essentially won a contest for being a BMI outlier”

I realize that, that’s why I picked the example, to show that it doesn’t work for outliers (and FWIW, he isn’t the “one person who has essentially won a contest for being a BMI outlier”, there are thousands of athletes around the world who are outliers and win because of it). Well that, and one poster said anyone over a BMI of 30 is obese…I stated that it depended on the definition of obese and that if looking at the true definition, he IS obese.

“Second BMI isn’t really supposed to be used to identify obese individuals, its supposed to be used to identify individuals prone to heart and other health problems. As I recall the Governator had open heart surgury fairly recently”

I believe he did. Now, was that surgery because he had a high BMI or because of decades of steroid use? To imply the surgery should have been something akin to writing on the wall because he had a high BMI may or may not be true, but to say open heart surgery was coming because of all of the steroids he was using will most likely be accurate.