I leave ERG mode on, but I pretty much live on the 3rd or 4th largest gear in the back (largest gear in the front). That seems to be the sweet spot for me to keep both the low and high cadences in a tolerable range.
This was a change when I first started since when I was out on the road I was usually on the two smallest gears in the back unless I was going up a really steep hill. lol
Is it just the low cadence that’s the problem? If so, I had similar issues. I naturally ride at 90-95rpm and so those portions of the early workouts were fine, but I found it a real struggle to ride at 60-70rpm. I decided to treat the power targets as my primary aim (as they get you the stars) and then try and vary my cadence as the plan wanted, but not to such a radical extent. So, instead of doing 60rpm I might target 75rpm. Part of my thinking was that I was getting knee pain at very low cadence and wanted to avoid injury whilst still progressing with the plan. However, as I went through the programme I found that the low cadence work got a bit easier as I trained more at it. Also, with hindsight, I think it’s a really helpful aspect as it develops the muscles and trains you to put more “force” into the pedals. It also teaches you that a slightly lower cadence (say 85rpm) will often result in a lower HR than 95rpm at the same power.
Saying all that, I think it’s really important that your FTP is accurate before you start - I don’t think the early workouts should be that hard (the really difficult workouts come towards the end).
Hi @David_Dickens !
How’s it going now? I ended up having to do the FTP test again to get an accurate result, which in turn made a huge difference in my ability to do the BMU workouts. After getting artificially high numbers doing the Ramp Test Lite, it was suggested that I do the FTP Shorter test, which is about 45 minutes total with a 20 minute test block in the middle that you do while not in ERG mode. Hope this helps!
Ride On!
Beth
I gave up 
The weather is starting to get better so I’m not going to have the 12 weeks to do it because I’ll be out on the road.
I have only got ftp increases when I’ve been doing the 4 week ftp booster.
When doing the booster you have these 60 minute free rides. Every time I did these I got an increase and then again at the end of the booster I did the 45 min ftp test and got a result of 231 watts.
I’m going back to do the booster again because I can fit it in over the 4 weeks.
The “Cucumber” workout was pretty rough tonight. Maybe because yesterday I did “Kirizuma,” which was another 1:30 workout. Or maybe I just didn’t get enough calories today. Either way, it was the first time I considered just not trying for the goal cadence toward the end, but I didn’t give in! 
Next week has a 2 hour workout. My backside hurts just thinking about it. I hope there’s some slower cadences in there to give me a better chance to stand up!
I did Cucumber yesterday too. Toughest so far, I think. I just about managed it, but 20 sec from the end of the final sprint bits, my legs just wouldn’t go round any more. Might miss out the “pedalling drills” in favour of recovery.
I have just completed week 4 and enjoying the plan so far but I have been finding it a bit easy. I’m new to Zwift and structured training. I’m 36, 74kg and my FTP is currently set at 218.
I only had Zwift a couple of weeks before starting the plan so not sure if my FTP is entirely accurate. I did the 20min FTP test a week before starting the plan and got 217 (although I don’t think I paced it very well). Anyway, I bumped it up to 218 before starting the plan.
I had read on this thread that the BMU difficulty ramps up a fair bit as it goes on, so I wasn’t too worried about cruising through the first few weeks. I was looking forward to the challenge of the Purple Unicorn session earlier this evening but midway through it I was again finding it easier than expected, so I decided to increase the bias to 106% for the 3rd interval and then 110% for the last. I didn’t find it too bad with those increases so I’m considering bumping up my FTP a bit.
My next BMU session is available Monday (week 4 only has 3 sessions), so I might try the ramp FTP test on Fri or Sat to see if that gives me a vastly different result from my 20mins FTP test.
Or should I just sit tight and wait for the tougher sessions to arrive in the coming weeks?