Please vote for the Offline mode implementation on Xbox Fitness
https://xbox.uservoice.com/forums/251646-apps/suggestions/6443433-xbox-fitness-download-offline-mode
Xbox Fitness : download/offline mode
Let the user download favorite programs locally so that it won't suffer from server issues (which happened a lot lately).
Keep the online requirement at startup if necessary, but at least let the program end without buffering or interruption, which can ruin a training.