That is an ineresting study. What I find that is different among todays athletes is the necessity to PLAN "tempo runs" or "LT Runs"
In my day as an athlete (I am now nearly age 50) I rarely if ever planned this type of run, but I knew that my body was progressing with the consistent running that I was doing when many of my runs became "up tempo"
When you become more fit as a result of the day to day "run as you feel" running your body will begin to beg you to change gears, work the hills & challenge yourself more. That is when you are ready for more intense work & racing. The amount of preparation is unique to each individual and cannot be had by looking at pre-arranged schedules developed by well meaning coaches.
Those schedules become important as a guide , later when the athlete is ready. That is simply what I take away from Lydiard, his influence. Though if you view my running logs on my website you would probably say I did not prepare as Lydiard outlined.
Lydiard provided all the "clues" I needed.
I believe that it is a natural progression where the athlete learns to read their body, how it is feeling.
Thanks for your contributions on this board!http://www.bunnhill.com/BobHodge/