[user104658]

Originally Posted by jet

Even boxing?
I personally couldn't bear the thought of my son being repeatedly punched and maybe ending up brain damaged or worse...

To be fair, though, that risk only arises at the middlweight-and-above professional level and so, again, anyone getting involved at that level would be an adult. Not WANTING your adult children to engage in risky activity is one thing, but really, when they are adults it's up to them. Of course, not encouraging them to take it up as a hobby when they're younger would be totally valid.

In my own opinion... I would only do that if they were interested in other physical hobbies. Martial arts and boxing are amazing in terms of exercise and, frankly, their health would be FAR more at risk in real terms having NO physical hobbies, than having boxing as a physical hobby. Especially as - again - there is no real health risk at the hobby level.