To access your workouts on your Apple TV, you will need to download the "Body FX Home Fitness" app from the app store.
Once this is downloaded, you can login with your username or password or you can activate your login at app.bodyfx.com/activate. A code will appear on the login page of your Apple TV.
Once you are successfully logged in, click on "Start Watching" and then click on the "Library" tab at the top of the screen. Here you will see your available workouts under "Purchased". Click on the your desired workout section and then scroll to the workout video you would like to watch click on it and then press the "Watch Now" button.