Yeah,like they could stop it.
The first useful things you learn in the army are what I call "The Three Golden Rules of Soldiering"
1: If there is no good reason to remain standing,sit.
2: If there is no good reason to remain sitting,lay down.
3:If there is no good reason to remain awake,sleep.
The army will provide you with all the discomfort you need. There is no good reason to make it easy on them.
I have actually fallen asleep while standing at attention in formation. You take rest when and where you can find it because you never know when you will have another opportunity.
Don't believe me,ask anybody who ever served in a line outfit.