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.
Yes - we recommend that you do these without ERG mode so that you appropriately hit the target you are capable of. With Zone 6 you have a range there and on ERG mode it picks the center. By switching off ERG mode you can let your mind dictate the pace or power that is within you. Woul recommend you consider joining us on Thursday mornings on Velocity with @Marjaana and me if it ever fits with your schedule where we do this session and teach the nuances of proper 30/30 HIIT sessions. Correct on your assumptions I would guess also for why the lower assigned load.