I didn't start racing until I was 32, although I rode quite a bit before that.
I raced for about 14 years, and was a Cat 3. I always did better in very long races. In those days, over the years I finally came to the conclusion that more training is always better, and lighter weight is always better.
Then I took about 15 years off, although I did continue to exercise and ride; I just never went to any competive events. I also gained a lot of weight.
So, since I came back to "serous" training, (as serious as it ever gets for me anyway) I tried to be more "scientific" about the whole thing. Shorter, more intense, plenty of rest days, etc.....It didn't seem to work all that well.
So I just seem to be relearning the simple training dictums: More is better. Lighter is better.
If you train a ridiculous amount of miles, and starve yourself until you are constantly light-headed and look like Mahatma Gandhi after a fast, you will be able to climb like a scalded monkey!!!!
Just my opinion. I know it is a "minority opinion" in the modern era of scientific training.
Luckily, I still seem to be able to train and push just as hard as ever (perceived effort anyway). I am limited by the amount of time I am WILLING to devote to training, not because have found the optimum amount. I was doing 250-400 miles a week in the summer.