Even when you're inside, it's important to keep in shape by simulating flying-snake attack scenarios. For example: oh, what's that creeping across the floor?
Like most creatures capable of flight, flying snakes are not always airborne. It's important to stay very still, as if you don't even see the impending snake attack, and then... Beat the crap out of that flying snake!
If you do this forty or fifty times per day, you'll be in good shape when you're outside and the inevitable attack arrives.
"Not everyone needs training to kill flying snakes, however." -- Elektra