Originally Posted by
Morimorimori
So, you can say that my fitness is rather unremarkable atm. I can't even reach a guaranteed 30kph on 100km distance on a not-so-hilly route, something that should be easily achievable on a roadbike by a fit person. And though there was an undeniable progress over these years, I'm starting to feel like I'm stagnating. I'm at about 250W of FTP with a body weight of 82kilos - and any further increase seem to require that much effort I'm just can't keep up with it. I'm starting to fear that reaching even 300W for me is close to impossible, at such rate.
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30 kph average moving speed in Rando terrain is damned fast. There have been a couple randonneurs on uprights in RUSA who have averaged that on 400k brevets and nobody has done it on 600k on an upright (under 20 hours on a 600K has been done in a velomobile for sure). 30kph is rare even on 200k and usually that is with riders working together. I searched the data and asked those who would know. 8-9 hours for a hilly 200K is pretty fast. I usually do 9-10 hours because I am not racing, I am training and in hilly terrain that is what works for me and does not kill me.
In 2015 at PBP, I weighed 83 kg and FTP was 271 or 272 watts. I did all 4 SR brevets in under 60% of the allowed time and did PBP in 54 hours. I share that to demonstrate, our W/Kg are not very different. But, here is the difference. I never considered FTP at all in my training. It was not what I was trying to improve. My key metric was constantly increasing wattage output at 1.5 mmol lactate. In other words, increasing my all day power. And, my qualifying brevets, my weight was 86 kg. So, you and I have not so dissimilar W/Kg. I am 26 years older than you. I do not want to go find the data but here is the point. You want to be able to ride for a really long time like a 13-16 hour 400K at the upper end of zone 2, say 70-75% of FTP, and you want to have a stable heart response at that effort (not a lot of "decoupling"). HIIT is not the right focus to achieve that. If you have trained properly, you will finish that 400K and feel totally fine. Sort of like you did a long hike and not a bunch of HIIT work.
I will try to find some material that might be helpful.