Heya,
I had a scheduled 5x 30/30s bike session today that was 37 mins long. I loaded it into Zwift and it said I should shoot for 325W on the intervals, ~120% FTP. I felt the first interval didn’t give me much stimulus so I thought I would turn off the ERG mode and do it by feel. I averaged the next 4 intervals at 375W and I still felt like I had plenty left in me for more. Also, my HR only peaked at 159bpm by the last of the 5 intervals. For context, I get my HR up to 170 at the end of a 20-min FTP test.
I think the power I produced was likely anaerobic range. I do think my FTP is accurate, but I just don’t think that if I targeted that 325W power there would be enough intervals to produce a VO2max stimulus. The AI did reduce my training load from the original workout, I wonder if it cut it far too short to even allow for a VO2max stimulus? This workout was on the same day as a swim 30/30s and is on the next day after a fairly high load aerobic day so maybe it wanted the load to be lighter.