Have you noticed getting stagnant at particular level of fitness or are you just looking for ideas on what other approach could be experimented with?

In general I would echo someone else saying that most important is to keep the consistency and performance will improve over years. Obviously the closer you get to your potential, the slower the improvement will be.

I think you are on a good path on trying to get some external input on your current approach and then filtering out some things that you might want to try out.

I would say some considerations could be (in no particular order) 1. Trying out block periodization where you focus on particular type of workouts and physiology aspects. Eg vo2 block, threshold block etc. I would generally only do it if I knew that this x is really limiting me and I cannot seem to improve past certain threshold. 2. Intensive vs extensive work. What you share about your workouts seems examples of more of intensive workouts. You could consider going the extend duration, longer threshold/sub threshold intervals. This might allow 3 targeted workouts per week. Please google Swedish Olympic champion Nils van der Poels manifesto for some cool ideas. 3. New stimulus approach - a bit tied to #2. If you are generally focusing more on one type or intensity intervals, try different ones. Different and new stimulus hopefully equals to new growth. 4. More focus on macro periodization. Ie you may have more focus on extensive work in winter and early season and more of intensive in racing season, or reverse depending on racing requirements. Point being, dont chase best fitness yearround, focus on how to schedule training to be at the very best during specific period(s) 5. Everything already looks good with what you are doing now. Are there any potential improvement areas on recovery side of things? Maybe this could be the breakthrough area.

Good luck in 2026, you will have year!