80:20

I read a paper recently by Stephen Seiler and Espen Tonnessen called "Intervals, Threshold, and Long Slow Distance:  the Role of Intensity and Duration in Endurance Training".  This was a very well researched and thorough article that helps give insight to how the best athletes in the world train.

There were some important things to take away from the article.

1. Elite cyclists train 25-30 hours a week.
2. 80% of their training consists of low-intensity cycling.  This is classified as below 2mM blood lactate (or below 73% VO2Max, or below 80% max heart rate, or power levels that can be maintained for 1-6 hours continuously).  Example workouts are continuous exercise without breaks or intervals.
   
3. 20% of their training consists of high-intensity cycling.  This is classified as above 4mM blood lactate (or 90-100% VO2Max, 90-100% max heart rate, or power levels that can be maintained for 1-8 minutes continuously).  Example workouts include multiple sets 5-40 sets of 1min-5min intervals.

 Here's a link to the article.  I'll probably write more once I've assimilated all the information in my new training plan.