PLEASE! I'm well past 40 and I wear what I want. I wear tight, low cut, logo t shirts all the time and I constantly am propositioned by 20 somethings. Age is a state of mind! Work out, stay in shape...and wear what you want. (If your pictures are any indication of your current condition, I say wear it!)
i disagree, actually. a woman can have a perfect body but at some point the 40 year old woman wearing little nothing surf shorts and a tube top looks kinda ridiculous at the pta easter egg hunt. part of it for me is that i don't find that fashion to be all that attractive anyway-- i'm more into elegant, sophisticated, and professional and was when i was younger too. in some ways, it's kind of nice being almost 30 where that kind of fashion is more required. there's also an aspect of professionality to it-- most women as they approach 30 and 40 have some sort of career and even if they aren't at work, they should dress in a way that, if they ran into customers, clients, or co-workers, would still make them look professional and put together. it may suck to have to dress to people's expectations, but it's how people are. i just figured this out myself in the last 2 years, and am trying to move beyond the early-20s me who was in art school to the 30s me who is a business professional. i try to keep my arty edge, but in a way that is more subtle.
the other thing is that women in their 30s and up aren't built like teenagers even if they are in excellent shape physically. proportions are a bit different, and since fit is so important in making someone look attractive and put together, clothing that is tailored for a mature woman over a 16 year old will probably look better off the rack.
the other issue for me is that when you're older and you've started to make a little money and find your place in the world, why wear clothing that looks like it cost $5 at Rave (even if it cost $300).
don't get me wrong, i think all women look great in jeans and t-shirts, sexy clothing, a good fitting swimsuit, etc., but they don't work if they aren't flattering, well-made, sophisticated and fit a woman's personal style which should include where she is in her life cycle.