I think I finally understand 80:20 training, and the benefits that you get. For the past 3 years, I have been reading about it, here, on Training Peaks and IMJ, and I have roughly based my training on this strategy, especially this year… but I didn’t quite get it, suddenly I had an epiphany, and it all makes sense:
After my recent event in St Polten, I have been training, but maintaining a relatively low intensity, however on the bike I have been feeling really good.
On Wednesday, I did a 34km commute PB, then went even fast on the (normally slower) return leg, but my HR was only 153, slightly above Z2.
On Saturday, I cycled my regular 80km club ride, and took 13 minutes off my PB, average speed was faster than St Polten, despite being on road bike, with 1200m climbing, again my HR was only 149 BPM, which is zone 2.
On Sunday, I cycled round the Zugersee lake, this is a 40km ride, with around 300m elevation, no significant hills, just rolling, it took me 59mins at an average speed of 40.6kph, once again my HR was only 155 BPM.
Finally, today I cycled up our local mountain, Rigi, this is a 12km, 1400m climb, I wasn’t chasing, or even watching my pace, so I was stunned when I got home to see that it took me 1h10m, over 4 minutes faster than my previous PB, My HR was 153 bpm
These rides were all at 260-275W, yet my HR was around top Z2 bottom Z3. None of these rides felt hard and my legs don’t appear to show any sign of fatigue. Compare this with a Hill climbing TT I did 3 weeks ago, 5.4km with 560m climbing, my AP was 311W and HR was 173bpm - which is above my LTR, and left me completely shattered after 24mins
What I think that 80:20 training has given me the ability to ride at a high power (265W) at a relatively low level of intensity, however, as soon as I go above that level, the intensity increases massively, for relatively little incremental benefit in speed