Katherine Camp is one of the NZ’s leading middle distance runners and the reigning 800m National Champ. This week she guides us through a fartlek workout designed to build that speed endurance and also teach the body to run fast and controlled when tired. WHAT Fartlek Progression Equal time of work-to-recovery: 2x90secs 2x60secs 2x30secs 4x15secs[…]