First time doing a fitness shoot

I am going to be doing my first fitness themes shoot in the next couple weeks and I am really interested in some tips for lighting techniques and so on. The look I am going for is an intense workout style shoot and we wil be shooting on location at his personal gym. My subject is a physique competitor and fitness intsructor locally in Milwaukee. I have 2 speedlights 580exII and 430ex (if they arent in my sig). Any helpful hints or suggested lighting setups are much appreciated.