Seeking endorphins!

[InfectedWithBB]

I find that a heavy workout makes more endorphins release in my body and the pain level decreases (from my fibromyalgia). Could you advise the most optimal workout for endorphin release? Obviously I cannot be overworking and need to follow a sane BB routine, but I think cardio releases more than weight lifting, but cardio done right after 30 minute heavy lifting is even better than cardio by itself.