if you work for a commercial, run of the mill gyms filled with soccer moms trying to lose weight than you can be a skinny nancy-boy. However in a gym that is a cut above the norm and there are a lot of ppl that lift for sports and that lift heavy, you better be a strong MF'er. It's so pathetic going to the local 24 hr fitness here and seeing all these losers weighting 140lbs, and don't give me that "Oh I am a runner" BS. You're not just a runner- you are a trainer. You should practice what you preach and have some semblance of muscle. Anyone can be a runner- this is very easy to do , much easier than being explosive, powerful, strong, agile and FIT. Sure you can help with rehab, and help the 50yr old soccer mom lose weight, but what about the varsity athlete who wants to be more explosive for next season? Or the actor who has to bulk up big time for an upcoming role? How about training MMA fighters? No perspective client that has some what of an athletic background will come to you if you are skinny. The bar is so low for trainers, since all it takes it for you to pass some run of the mill training course and do your paper work. Fortunately, at my university gym, lots of the dudes are jacked and we have varsity athletes and the skinny fitness world trainers have no place in such an environment. Fuck, I've even seen fat trainers at the local 24hr fitness. *barf