George

How many years does it take to get to peak performance, it you ride 20 to 40 miles a day, 6 days a week? I've read where some coach's have said 3 years while others have said up to 7 years. Thats taking in intervals and sprints as well.

rruff

Intervals and really challenging your limits is necessary.

I improved ~70% (1hr power output) in less than 6 months. In the next 6 years I added less than 10% to that. Endurance probably improved more... but basically you tell how good you are going to get if you train hard for a few months.