Wet Coast and HRE, Thanks for the input. I completely understand that knowing what works far supersedes understanding the science behind it....I was just curious as I had not heard this particular strategy before. Although I did meet lydiard during my competitive years I only had very generalized knowledge of his training theory. I was trained under a Jack Danials oriented program, and although I ran sub four minutes and sub 3:40, I am beginning to realize the impact that Lydiard and on our sport, and wish I had tried his approach in my youth. Regardless, I am conducting a grand experiment and have started running 90 min a day(singles) plus a weekly long run to see what happens.........