Can an NCO make me come in every Saturday for weeks to do PT, rucking, etc. (not being corrective training)?

We need you to change your fake name (John Doe). We don't allow members to post using fake names. I've suppressed this question until you make the change.

http://support.rallypoint.com/customer/en/portal/articles/1311927-how-do-i-change-my-name-?b_id=4766

If his intent is to correct a deficiency he see's in you, yes. Yes he can. Be happy you have an NCO that cares that much about you. Its their Saturday too after all..