I do hot Bikram yoga in London, and 30 day challenges are fairly common. you can skip one day a week only if you do a double on another day. I get the numbness and tingling in my left thumb forefinger and middle finger. Today it has not gone away after class as it did the last two days. I am going to do a double tonight and take tomorrow off. Do you think I should skip bow pose? bow pose is definately what sets it off, the tingling goes into my and and wrist. I was also considering seeing a chirporactor because maybe some misalignment in my spine is pressing on a nerve. I have your book, and I am doing the bow propertly, although I cannot yet do standing bow properly as my leg seems to splay out a lot in it.