I know this is completely irrelevant to trading. But when you trade long hours, you may face a health problem. I heard one time that a floor trader's heart beats faster when he trades from his own judgement than that of a rancher who is accidentally kicked by a cow. Mental health is very important. But here in this message, I would like to write about a back problem. We, traders, researchers, whatever you name it, may end up having a back problem. The reason why I decided to talk bout slipped disks is my teammate is going to see a doctor today. She has a backache. I hope she will be fine. I also hope everyone in this forum is OK. There must be millions of millions of discussions of how to avoid slipped disks. So what I am going to say must be redundant or even meaningless, but from my experience when I stretch a little bit after I do something, say every one hour so, I do not have a back problem. Let's have good trading with good health!