FastCAT is part of a larger "coursing" sport, originally for Sighthounds, such as Greyhounds. FastCAT is a straight line 100 yard dash, with the dog chasing a white plastic bag being pulled by a pully system. If your dog has prey drive, she will love this sport.
Here's a link to the AKC FastCAT information.
Challenges for the Dog
For an avid dog, this is extreme exertion for less than a minute. Running flat out can open a dog to injury, and there's a small chance of getting caught in the pully system. Dogs that are nervous or less engaged may run off the course, frightened or even panciked. Most courses are not securely fenced, so a frightened dog can run off of the property.
Challenges for the Handler
Plan for a lot of walking, as fields are often a good distance from available parking. It can sometimes be difficult to control an excited dog when it's waiting for their turn.
If your dog loves to chase, you can get her used to chasing a bag. On the course, the dog's prey drive is likely to kick in, and it's mostly on instinct.