Just thought I’d give an update on this a few months on. I continued my initial approach of [relatively] large volume Z2 riding approx 200miles/week with CTL averaging 90. I’ve ridden 4 ‘ultra’ events in the past 4 months (an ‘Everest’, the Pendle600, The Yorkshire Beast and the Pan Celtic) and exceeded my expectations on all of them.
4 weeks on from the Pan Celtic I’m fully recovered and my Garmin calculated VO2 max is now 63: up from 55 average in January (which was after 12 months of more ‘traditional structured’ training).
I’ve not tested my FTP recently BUT I would say that I feel good and that on group rides I’m comparatively faster up the hills of N Wales than I used to be and I’m recovering faster from ‘efforts’ than I did before my 6 month block of ‘base only’ training.
I’m not suggesting this approach is necessarily right but it’s worked for me this year…so far.