Also want to stress that pets and children and trainers don't mix well. I hope (pray) no one here is as stupid as some of the folks on ******, but there are some very unhappy posts there about tails, paws, etc.
It's not realistic to ask a cat to avoid it generally, but if you can't close off your training space, you may wish to think of a solution for that inevitable moment where Mittens, after months of stalking, carefully crouches down out of your sight, and then springs forward to attack! ... and becomes Mitten.