In reply to Lurking Dave:
I think you'll need to design for at least 200 kg load. You might weigh 70 kg but you'll exert more than 1g when you swing, pull-up or drop down. So make that 70x1.5g = 105 kg. And you'd want a margin for safety, say a factor of 2, so 105 becomes 210 kg.
If you drill horizontal fixings for your (mostly) vertical load, small bolts should be strong enough (say two M5 bolts).
However, if you drill vertically, your load will try and pull the bolts out, so the only thing stopping that is friction. You'll exert much more load on the bolts (and the surrounding structure) in order to achieve that level of friction. Horizontal fixings is the way to go.