Aunty meldy speaks sense.......
The aim is to hit Feb/March all guns blazing... The weather gets better and out you go for your long rides.
In my first year, I did the Vit, had a week off, then cracked on with training for my first IM.... My mentor suggested that I calm down ablt.... (perhaps brick sessions in October before work were a bit over the top, and 20 hr weeks in Nov were not maintainable). Gom was right....
The long runs trucked on over the winter with no issues
I struggled to get out for more than 2-3 hours over winter on the bike. My feet just froze.
Things then picked up in March onwards..... built up to some 6 hr rides...
Even so I felt CBA by May - did the Swashbuckler,a couple of sportives, but apart from that did not hit anything massive in June, ie a big taper.
So the moral of the story is building endurance up for the first time, (and subsequent times) is hard, and takes comitment. You need all your *oomph* from March onwards,
don't use it all up know...
However I like my junk miles on the bike....I commute by bike as it saves me money. People say they are junk miles, but on the otherhand something has made me a strong biker......
(now I've got the endurance my coach is pushing me out for long rides now, but then I'll be tapering from the end of April, and will miss / cut short rides in Jan/Feb)