Well, beyond just health, it actually makes sense to take breaks from a raiding perspective. The human mind need to refresh. After a little over an hour, a break actually helps you stay more focused and productive.
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I didn't say that. I said that if the guild isn't taking any breaks over a for hour period, then if that's something that's becoming an issue (I'm assuming he's spoken to them about it since the discussion about g kicking had occurred) then it sounds like he needs a better fit with a guild that runs raids in a way that makes sense.