Mine did Oct 8 this year and my fitness nosed dived for two weeks before I realized it wasn't my training, but their program. I initially had my max HR set up and let the zones fall where they may, but then I decided to set it up to use my zones and that is where the program failed. Got a service ticket on it and the guy at Strava told me to go back to max HR setting. I did, but adjusted it form 183 to 172 to get my zones to line up better. Worked like a charm, but not perfect by any stretch. But, I'm a noob so what do I know...