Officially mid-way into my 50's now and my love for KI, coasters and amusement parks in general has not faded one bit since I was a young kid. But my tolerance level sure has!
Multiple rides on The Beast, Mystic, Diamondback, and Orion don't really bother me too much...but I pace myself now and try to hit the bumper cars or some other kind to the head and stomach rides in between. Even though I am in good shape for my age, coasters with inversions such as Banshee, I am one and done for awhile depending how long I plan staying at a park any one day. My equilibrium just isn't what it used to be unfortunately. Loops didn't used to bother me, but in the last few years, even with trying anti-nausea pills, I just cannot ride coasters with loops near as much as I want. But, saying that, I love to ride RMC's and the inversions in them don't affect me as bad. Strange!
Of course, when I was a kid, the Rotor about killed me as far as that goes. I was so sick after riding that! I was so embarrassed! I never could really handle any ride that spins. Even as a kid. Build a 500ft rollercoaster though, and I'd be first in line.