There is a trainer at the barn I work at who is in her late 40s, and she has a 3 year old gelding that she's trying to break to ride. The horse only leaves his stall for a few hours at night when he's put in the indoor arena with another horse, or he leaves his stall when she is training him. She claims that she's too old to get thrown, so she ACEs him before she rides him EVERY TIME. There are times where she rides him every day for weeks. She's been doing this since October, and she hasn't gotten far with him training wise. She lunges him for a half an hour with side-reins, and then has someone walk her around while she sits on him for about 20 minutes. In the beginning, she was having another person ride him, but she was thrown 3 times. I'm pretty sure I've read some where that ACE impairs learning, so that would probably explain why they haven't gotten far in his training.
Giving this horse ACE so often can not be healthy, or am I the only one who thinks this? She even told me that she has to lie to the vet and say that she needs it for clipping ears because he won't sell it to her otherwise. Also if you think that you're too old to train horses without drugging them first, I think it's time for you to retire.