This fartlek session starts slow and long and finishes fast and short. It can be adapted whatever training cycle you’re in and is fun, free and also numerically pleasing! WHAT? PROGRESSION FARTLEK 16mins, 8, 4, 2, 1, 30s, 15s (getting faster as you go) w/ 2min recovery jogs Terrain: Undulating trails w/ somewhere flat for[…]