Script to Screen: Story Re-Write

After some feedback I decided to re-write my initial story, taking on the feedback I have been given while also making some choices. Firstly, rather I thought rather than the conflict being between two guards, it could be between a guard and a prisoner who's running the prison, making the external conflict more extended than just the guard wanting to fit in. 

But, I don't think the story is quite there yet and feedback would be appreciated. For a start I don't know if the guard / prisoner conflict works in relation to the method he takes to pursue becoming a bodybuilder (like is the conflict too dramatic to justify what he does or is it too un-realistic ?) . Also I still have some problems with my ending, as I was torn between having this ending, that I'm worried could be seen as a cheap ending, because the first scene plays out with a clear goal, and it never gets resolved in the end, or whether I should, of have had a happy ending, where the guards hard work pays off and he beats the prisoner, but with this I felt the story would be either too predictable or veer back off into being a super hero origin story. 

Also I would like some feedback on the structure, especially if the second act is too long, or of the guard overdosing on the medication should be the resolution to scene two, rather than the opening to scene three as well as if it looks too long / complicated for a two minute sequence ?