The traditional approach to cycling training, and endurance training more broadly, is periodisation, that is where the load is gradually built up over a period of time until nearer the target event the load is reduced and a period of 'peak form' occurs. This is then followed by a rest/transition period.

And, this approach is still highly adopted at the top levels, think of a Tour de France rider, who builds their whole season around the Tour - they use the racing beforehand to build their form and fitness (with those races often picked based on how they fit into a periodised training plan) and after the Tour you see them stop racing, or racing at a lot lower level (of fitness/form).

There is great article on Mat Hayman's training here. Interestingly, he makes the comment "“The season is now periodized for almost every rider on every team. Gone are the days when a rider would just go from one race to the next all year… the only training pretty much being recovery!” -M.H." This is true, but also belies the fact that periodisation is not a new concept, stemming from Arthur Lydiard in the 1950/60's.

The article (and a previous article) include the following two PMC Charts:

These charts show us Mat's fitness and form for the all of 2015 and into 2016. Importantly, whilst it is a periodised approach to training, it doesn't present as what you may think of as 'typical', in fact the only big variation is the end-of-season break. During the year the load is relatively stable. What observations can you you use in your own training:

  • Finishing the season at the Vuelta, allowed Mat to start 2016 at a higher level, even after a period of non-riding, than in 2015, where he did a different program of end of season races (in 2014).
    • a good way to set yourself up for next season is to finish the current season with a hard block.
  • The December build period is very important to Mat's season. Over the years Mat has moved to exclusively no racing at all during this period.
    • during your initial build/base don't dilute your training with racing or other activities that prevent you focusing on the what's important now.
  • The Tour Down Under is the capstone on the build/base period, getting in a final period of overload before heading into the race season more generally.
    • add a stage race / training camp / big week at the end of your build/base making sure you get the most out of your plan.
    • this period of overload allows you a bit more recovery before moving into your next phase, without losing form/fitness.
  • At the end of the build/base, post Tour Down Under, the level of fitness/form remains relatively consistent. But this isn't through doing the same training week after week, rather through targeted interventions (stage racing, training camps) where particular physiological responses are developed.
    • build bigger week long blocks into your training plan to focus on particular pyshilogical responses, for example:
      • a week of Zwift racing for threshold/VO2
      • a mountain training camp for climbing/tempo
    • This approach also works well for those with jobs(!), where you can swap between a bif work week and a big riding week.
What I also see from Mat's training is that he could hold his form/fitness for relatively long periods of time, through regularly (4-5 weeks) having a period of overload and a period of rest. And this was still a very high level, with a Paris-Roubaix!

So, compare your PMC over a longer period of time (18-24 months) to Mat's, maybe there's some things in there you can try.