What is a Trainer?

[Veronica]

I was just reading some of the messages and noted that someone said they used a trainer. Initially I thought this was a human but saw someone else say they used a trainer when they can't ride outside. Is this a stationary bike? A software program like Wii?

Depends on context. I have a trainer (a human being who tortures me). I also ride my bike in a trainer. You can purchase videos to do while you ride your bike in a trainer.

Veronica