Is it normal for a healthy, active 36 yr old to get extremely stiff & achy in the morning & after sitting 1 hr? legs feel they will crack. i stretch.

Not normal: Suggest physical examination and perhaps additional studies looking for causes of arthritis like early rheumatoid arthritis.

Probably not: Your symptoms are interesting and they could indicate early arthritis, many arthritis patients complain of morning stiffness, i advise you to discuss these symptoms with your doctor.

Well: Not really normal but it happens. It might be your mattress. I bet it works out after you get going. Lots of people get stiff after sitting in one place for a long time . You need more exercise than stretching.

No, it's: Not normal but not unusual. If persistent or associated with fever then get seen but you may have a bad mattress or something simple. Good luck.