I didn't really notice much decline in my 30s versus 20s. I was at my peak fitness around 41 (not as powerful or fast as my 20s, but way more endurance and stre

I didn't really notice much decline in my 30s versus 20s. I was at my peak fitness around 41 (not as powerful or fast as my 20s, but way more endurance and strength). But my early 40s were a pretty rapid decline as I had a bad knee injury that involved a long recovery and we had two kids which meant sleep deprivation. At 43 now I'm on an upward trajectory again in energy/fitness but time is total dumpster fire - getting good at very efficient workouts and mental health breaks!