I don’t think this would affect personal, live fitness instructors. Although it looks the same on the surface, the value proposition is very different (as is the cost).

You don’t make the same kind of human connection when the communication is one-way.

Put it this way: if internet streaming was going to kill off fitness instructors, it would have happened already. Apple isn’t doing something new here, they’re just putting their own spin on it and vertically integrating it.

Companies doing similar services might have more to worry about, though I think there is a lot of room to grow in this market, and i think it’s “niche-y” by nature, so I think there’s probably plenty of room for competitors.