So I'm talking about specific Star Treks, mainly the Original series and Discovery. It seems like they would at least have ergonomic chairs like most offices have. At least TNG basically has super deluxe car seats. The Original series I understand the low budget set build int the 60's but Discovery should have the technology to have chairs that look like they're meant for people to sit in them for long shifts.
There are weight and oxygen factors but a ship filled with water would help absorb energy impacts and those pesky hull breaches as the water would freeze around it. Just a thought as you could float and be super comfy.