Hi ,
I have a question about the endurance workout of TR. I just used 2-hour endurance ride with TR Boarstone (my first time) that different style from I trained in the past , I always train my Zone2 like 1st W-up + steady 56-75% FTP by my feeling in that day and training duration + Cool down . So the program seem alternate the power all the way ( every 10-15min) in Zone2 . Could you explain me about for this style? Is it better and Why to train like this?
Thank you 
It is not better. It’s just for variety. When it comes to endurance and active recovery workouts, TR repeatedly says you are welcome to do whatever fits your mood/schedule/etc as long as it is mostly in the correct zone and accumulates roughly the target amount of TSS. In fact, many people do these outside. On the other hand the other more “interval-ed” workout types (sweet spot, threshold, VO2MAX, etc.) have the intervals designed a specific way and are usually part of a training block progression and therefore should be done as accurately as possible.