If you want a custom workout, you have to use workout buddy which the watch cannot use without your phone. I bought this watch to run marathons with intervals of walking and running plus listen to music without my phone. Can't set up intervals without workout buddy, hence the problem. Plus you're limited to 99 intervals and I need more for a marathon Also, downloading music from my phone library is ridiculously slow. Have to select individual songs, albums or playlists and if too big, doesn't download. Should be able to download entire library with one selection. Also disappointing is the accuracy of the watch for distance. Ran the Fargo Marathon and my 10 year old Garmin forerunner was more accurate. The apple watch was off by over a half mile. Supposed to be state of the art tracking so very disappointing. Waste of $800, will be using my old Garmin for intervals and accurate distant measurement.