Most bodybuilding message boards are more a form of entertainment than a source of information. People post supportive accolades with little substance and argumentative insults with the sole purpose of having a presence and becoming popular in the community.
Once the message board is driven by a community, they develop a store to create a profit center. The real purpose behind the message board is just to have a loyal community to drive customers to.
The fact that this site is not like the others is what drew my interest. Putting time and effort into well thought out answers to real questions just to have them pushed to the bottom of the page by people promoting their websites, products, services, and themselves is disappointing.
Message boards that are comprised primarily of people from the bodybuilding community have a unique problem. Some examples...
Bodybuilding is very competitive, and there is a mental game involved as well. People tend to only tell half truths about their training methods. Imagine a girl who looks fantastic after losing 30 pounds. She may post that all she did is cut out soft drinks and start running 3 times a week. Now imagine if you were preparing for the same competition she was and you've struggled to lose 10 pounds so far. That could be a discouraging thing to read of one of your potential competitors. These people contribute incorrect and misleading information.
There are judges who train competitors which is complete conflict of interest, but it is commonplace in the bodybuilding world. People will try to have a strong presence on a site just to talk themselves up and inflict an opinion of themselves on judges and those who run bodybuilding publications. These people only contribute shallow exclamations on forums.
One other dilemma with bodybuilding sites is that many competitors take drugs that are illegal, therefore very controversial. That automatically leads to misinformation, because even if someone is thorough with diet and exercise plans that they are using, they will not offer information about the drug regimen they are on. If they are upfront about drug use, they will face criticism from others. This conflict develops into a lot of arguments and muddies the site up.
My point is that I don't think it will serve this sites purpose to focus too much energy toward drawing users from bodybuilding sites. I would expect a slow growth if you want to attract good contributing members.