I’m also a newbie in the midst of a 30 day challenge (today was day 24) and am experiencing the same stiffness in my lower back. Half-moon and camel hurt quite a bit, as do the forward bends and even the sit-up. I’m thinking it could be due to my jumping in too quickly with improper form? On the first few days, I was feeling SO good and probably went too far back into the back bends. Dom, your core theory is interesting! I’ll have to pay more attention to that in class tomorrow. Does anyone else have an idea on how to relieve this soreness?