I've had an old school lesson taught to me today. I went to see the guy that bought the Asils I was interested in.
Some people may disapprove of what follows and I'm still not sure what I think of it myself.
The Asils are kept as pairs. They have their own runs and the runs are well separated.
These Asils in particular and probably many others have ancestors that were bred for fighting. Apparently it's not just a question of breeding for aggression because apparently it doesn't necessarily breed through the generations. Heart condition is vital in fighting birds. A lot of roosters die of heart attacks in prolonged fights. Those that breed fighting birds, train them for fitness just like fighting humans.
This guy does not and never has used his chickens for fighting but, he says that there is a lot of knowledge on chicken fitness in the fight circles and he wants to keep his birds as fit as there ancestors.
Anyway, I watched him training two roosters and I can't fault him for inventiveness.
He's made spur boots, they are tight fitting tubes with a small rubber tip inserted. They strap around the roosters legs. His wife made leather boxing gloves for the feet.

They work really well although for the first couple of attempts there was too much padding underneath and the roosters lost their balance a lot.
So, he puts a couple of roosters in his training run and lets them fight for a bit. Even with the boxing boots on and the spurs covered the speed and style is amazing to watch.
One rooster can do a somersault right over the back of another.

He trains the hens as well but in a different way.