I am so in agreement with everyone else. I'm 51 now, and over the past few years I just don't like pushing myself to the limit any more. It's not so much that it fatigues me more or is that much more difficult, but mentally I just feel like "Why???? Why am I trying to lift heavier and heavier, and do more and more intense intervals?" I just feel like, I'm plenty strong lifting light-to-moderately heavy weights, I'm in good aerobic shape, my heart and bones are strong, I"m flexible, my lab tests are good, I'm happy, I sleep well, and I've accepted that my body will not undergo dramatic changes as a result of the way I work out. (If I adopted a totally clean eating style, I probably would get dramatic changes, but it's not worth it to me to do that.) So I'm doing less Cathe and more Firms, Kelly Coffee-Mayer, Jari Love, Dove workouts, etc., lots of Kundalini yoga, more walking than jogging. I finally feel like I'm "good enough" and don't really want to challenge myself as much as when I was younger. A few years ago I did P90-X and was very proud of myself, although my body didn't change much. I have no desire to do the X or STS or anything like that again! I wish Cathe would make more intermediate workouts, because I adore her and her teaching style, but I think she will continue to play to her "base" (sorry, the election is on my mind LOL) of people who love very high aerobic intensity and very tough weight workouts. I still have a lot of intermediate instructors to explore, I've Netflixed some Denise Austin (stop that snickering~!) workouts that were surprisingly challenging, and I may jump on the Leslie bandwagon. For me one of the pleasures of middle age is cutting back a bit on the high intensity and relaxing a bit more, in all areas of my life.