*Ahem*
I did my first BB show when I turned 35. I was in better shape than ever before. Had some rebound due to some stuff, but now, I will be *39* in 7 months and I suspect I will look better than I did on contest day at age 35.
There is a degree of muscle maturity as you get older, but you also are dealing the results of reduced hGH production, estrogen, etc. You have to work hard. The hormone changes alone are hard to anticipate. For me, the biggest change I've seen has been in my skin -- no more acne! When you look at someone like Madonna, you have to remember that yes, she's over 40, but she's also a perfectionist and has been training her body intensely for several years. She's also starting to lose a certain degree of elasticity in her skin and as a result, as long as she doesn't start getting fat, she's going to have a more sinewy look. I also have several years of heavy training behind me to build on so I have one up on the younger crowd as well w/ the muscle maturity, but I'm still not as blessed w/ the metabolism as I could be w/ more work & discipline. (We'll prove that in the coming months....)