Exploring Eorzea is a thrilling experience.

During you time here, you will be able to talk, join, and
adventure with many other individuals in an experience
that is unique to online games. That being said, we have
no desire to see your real life suffer as a consequence.

Please do not forget your family, your friends, your school, or your work.

Do you wish to continue?

~FFXIV Start Screen Message


What I take from this - play healthy without neglecting your social life and you should never have to worry about the fatigue system in the first place.