I don't feel ashamed. I am working out. I find this kind of message haughty and gross. I'd rather people be motivated through positive reinforcement and the idea that they can feel and look great. Not this "look at me, what's your problem anyway" garbage. It's pure ego and not about others.
Thats the thing though, to some people this is positive reinforcement. Not everyone views reinforcers the same way. I can give one money for good grades, while another wouldn't care.