Drummers have terrible backs, and lots of repetitive hand and wrist type injuries from percussion injuries.
Sitting on that little seat while whacking away at things just sets them up for years of later pain. Most people don’t realize that true musicians are like atheletes.
Even singers put a lot of physical effort into singing. Just look at a clip of Ella Fitzgerald singing. Lots of muscle control in the abdomen. Every performance is like a yoga session. That’s one of the reasons older singers can lose their voice - they physically don’t have the strength anymore.
Perhaps it's all those "drams"(American translation - tots of whisky) sent up to the stage every night!