Is it do boxing or go boxing?

It could be any of the three :

1. The verb would be most usual if the person was a professional or really serious about it : Henry is a boxer. He's been boxing since he was ten. And if I had to put a bet on the most common in any context, it would be the verb.

2. Karen is a policewoman and has to keep fit. She goes running, does weight-training, and does a bit of boxing too. Here, the use of the quantifier is important. I can't imagine saying does boxing but does a bit of boxing sounds fine to me in this context.

3. David loves contact sports. He does judo, karate, and goes boxing once a week too. This sounds the least likely to me, but possible in the situation where it's just a hobby, the person attends an organised club, etc.

Thanks a lot susan!