This workout is the natural extension to Zane Robertson’s fartlek session last week, with a tweak in either direction on the endurance-speed scale. WHAT The 3-Level Fartlek 5x2mins @ 10k effort (1min jogs) 5x1min @ 3k effort (1min jogs) 5x30secs fast (90secs jogs) Terrain: Undulating mixed terrain. Stable under foot. Feels: Relax and find your[…]