Is TNA fake?
Just like any other Professional Wrestling organization on television, TNA is predetermined for television purposes. The moves that the wrestlers perform are predetermined, that doesn't mean they don't take a beating. Speaking from having in-ring experience, I can tell you first hand that unless you are one of those people who have never been in the ring before, you'll really will never know what it is like.
I trained under an independent company, which quite frankly, "Indy Companies" take the aspect of the actual sport seriously. As to where you see the "Big Time" companies such as, the WWE, most of the time have to be choreographed due to television time. I watch ROH Wrestling myself, for one, they actually take the sport more seriously than the TNA or the WWE because those two companies have mostly forgotten about the sport aspect.