I know what you mean about stiff wrists. I am a beginner and had to start with 5 minute practice sessions. Then my wrists, neck, and shoulders would be sore for the rest of the day. I even had to take days off in between to recover! I’m only 45! Its been 3 months now and I can practice daily for 20-30 minutes. My wrists still get a little sore though. I do think as adults, we enjoy the process more and are more patient.