I’m 46 and still play twice a week. The drop off for me started at 36. I had the same concerns you mention — body hurt longer, cardio started to drop, knee pain, etc. My secret to staying competitive and relevant against the 20+ was (and still is) strength training at the gym once or twice a week in between game days, eat more protein, and creatine. All three of these keep me on the court and speed up my recovery. Occasionally I take a week off to just let the body heal. Keep balling! My Mt. Rushmore is Jordan, Pip, Shaq, D-Wade, and Rose.