FTP builder, FTP

Was wondering if program like FTP builder was more effective, than say just doing races, or interval rides. I’ve gotten stronger through riding/racing, but for some reason zwift doesn’t give me an FTP boost…3.7w/k results in events. Not that it matters that much but would like to see if I can boost that closer to 4.0. Which route is best? Have also noticed that significant leg strength work in the gym has made a real difference for me. At 57years strength matters more I think.

I am following the 6 week FTP builder program at zwift and near the end of the program now, I am not that enthusiastic. To start with, the program does not mix well with the weekends where I have more time to ride (also outside). The problem is that the program has its toughest workout on Friday and also the workout on Monday is not the easiest. For me, a recovery day on Monday and Friday would be best. Also, in week 5 there is a sudden increase in intensity which is weird. Also, some intensive workouts have a cool down and others don’t. On top of this, some workouts seem like a random collection of intensities combined and this makes them just hard to grasp mentally. Now, I am in doubt whether to finish the last week or simply skip it alltogether or skip some workouts. It sometimes feels like I am near injury. Going to continue with workouts following the time crunched cyclist. I will simply create my own workouts in the future in zwift.