It looks like this from what I can see: http://andersontrussnc.com/floor-trusses/
So - obviously I can't be drilling an eye bolt into anything I see here. I've heard people talk about sistering together trusses by laying a doubled up board or 4x4 between them and screwing the eye bolt to that. But ... that wouldn't be safe to do from the BOTTOM of the truss in the open triangle, right? Wouldn't it have to be attached to the top?
Kind of frustrating - for a home gym looking at a pull up bar, punching bag etc...and I just don't see how it's possible without tearing down a lot of sheetrock?