Charlie, Coaches and all you Sprinters out there. This old football coach would appreciate your help.
First let me say, I have applied Charlie’s principles for years and I thank you Charlie for sharing your knowledge through your books and this website. You have done Canada proud.
My question: Can you time the rest intervals between Tempo Runs and Speed Work by using your Heart Rate?
(1) 50-60% of Max HR between Tempo Runs
(2) near resting levels without losing your “pop” between Top Speed Sprints