Seriously, I'm not trying to put your hobby down, but we Amercians - due to our economic success - have very sedintary work lives. We are also taking up quite sedintary hobbies, and the combination of the two is bad news for everyone's health.
If it helps sell the idea, explain to your kids that real-world sports is like an ATI X800XT videocard, but with real blood!
Sports suck.
How about foil fencing? Who says we don't do sports? My older boy just got his black belt. The difference is I am a grandfather and I am always with my kids. If fact I outran the little one on a Barbie jeep two hours ago.
Do that too. Hey, I have an idea. How about doing both!!!??? Then you can claim you're well rounded.
Honestly, sports aren't all they're cracked up to be. Wait... maybe that's cause I'm remembering the time I "cracked" open my chin big-time on some cheap 4x4 goal post that ran up and smashed me in the face when I wasn't looking. Lots of real blood for sure. I guess in retrospect I prefer cyber-blood 8^).