Male Anatomy Practice Sheet

I know that I'm gonna be drawing males mostly so I need to study some male anatomy. Here's a quick sketch dump of males doing poses. Two of these poses are from an anime. The rest I made up. I feel awkward posting this!
  
I will accept constructive comments, so feel free to leave some! 
My fave pose is the middle one TBH 
Also the right corner sketch I did very quickly so there aren't really details on that one so you guys can ignore it. Anyway bye!