Appropriate networking with other health related professionals.

If a personal trainer has a network for referrals (massage therapist, physician, chiropractor etc.), should he or she avoid doing business with those same professionals? (ex. If the PT has a massage therapist they see for their own needs, is it wrong to refer a client to the same one, or to the give the MT business cards or flyers to advertise their personal training business?) I think I know the answer to this, but I just want to see what you all think. IF…………the answer is YES, then how can you know you’re referring the client to a good professional if you haven’t used their services? Would it be just based on the reputation of the other professional?