Should I be concerned about my Body Mass Index?

I, like many others, want to have ripped muscles with defined abs like those people in TV commercials. The question is: how important is the BMI when one wishes to attain such look?

I'm talking about this kind of look: http://i96.photobucket.com/albums/l182/coconutgt/model1.jpg

Not this: http://i96.photobucket.com/albums/l182/coconutgt/bulk1.jpg

Another question is for those with experiences on this topic. What is the weight range/body fat % for someone such as myself (5'8") to have that kind of body? I know it varies from people to people, but I want to have an ideal number to aim for to adjust my lifestyle accordingly.

Also, if anyone has more information in regards to this topic for me to read up on, please don't hesitate to do so.

BMI is notoriously useless for athletes, weight-training individuals, and pretty much everyone except the average sedentary assclown.

BMI is pretty useless. Even shotting for a bf% can be misleading, as some people have abs at double digit bf%'s while some have to get very lean to see abs (not to mention things like water retention, skin thickness, carb depletion, blah blah blah).

You may wish to look to the tape measure if you want a reliable yardstick for progress. Try to get your belly down to a certain number, or your arms/chest/legs UP to a certain number while keeping the belly measurelment fairly stable, as a means of establishing a goal. Bsides, getting an accurate bf measurement repeatedly is a real chore.

+1
BMI is wizzaaaaaaaaaack. I know, because it says I'm in good shape.

BMI is horseshit. That about sums it up.

Perp

BMI is a load of shit. Totally useless for anybody who lifts weights, and even for the average sedentary asswipe who has a bigger than average frame.

BMI says Im borderline underweight, and I have always been very active! I got a small frame. Makes my muscles look bigger I say

Nice gyno in that second pic there.

Barry Sanders had a BMI of 30.4 in his prime. He was pretty quick for an obese guy.

as everyone above has stated BMI is useless.

at your height to look anything like the model you'd probably have to be anywhere between 170-180lbs with a decently low bf% though as one of the other posters mentioned an exact bf% is difficult because of the difference in the way each person stores body fat. realise your own limitations and live with them as long as you're convinced you've done everything you possibly could.

BMI and having visible abs are utterly unrelated. Neither has any bearing on the other.

BMI is nothing more than a consideration of your how your weight relates to your height. It doesn't bring any aspect of body composition to the equation.

The classic example is that Arnie was obese according to his BMI when he last won the Olympia. After performing the BMI calculation, the result is cross-referenced against a list of words which common parlance uses to refer to levels of fatness/skinniness. BMI and fat levels are unrelated, although often correlated in your average Joe Couchspud.