Notes
Tried some speed 4 x 1/2 mile (approx) after easy mile and with easy 1/4 mile rest periods in between. The 1/4 mile loop was ~1/3 medium incline, ~1/3 medium down, and ~1/3 flat. Then easy after. Quads tight after Burn with Kearns core killer workout. There's lots of lunges in this thing! Last I checked, quads weren't part of my "core"!?! Hope in the end it helps me get stronger and faster...