[QUOTE=Yogabecs;86270]Mostly Hatha Yoga but some power yoga/vinyasa too which are faster paced.[/QUOTE]
In my case, I also have experienced insomnia doing hatha yoga in yoga classes. In the same period of my life, doing asana and pranayama yoga in my room, just by myself, I slept well. Then I stopped to follow the class.
The reason for this, I think, is that hatha yoga is powerful in circulating the energy, and doing it for one hour with the “master” that pushes you to stretch more and more to your limit, was exactly what I did NOT need. I remember that I sweat a lot too, during the exercises. This, I believe was due to the internal release of heat. And, I suppose, it is a clear sign if you (or someone more expert) can read it.
Probably, as others have said, it was not the hatha yoga the reason for the sleep disorder, but rather my lifestyle. But it is also true that, if you open some hidden boxes by the yoga, the content will have various results.
I continue to do hatha yoga by myself, less intense in time and stetching, and I have not experienced any problem. The moral is: find your way!
Al the best.