My Version of Farlek Run 5, 4, 3, 2, 1 Fartlek training is a kind of running training which involves random variations in speed and intensity, alternating between bursts of Fast and slower 'recovery' jogging. Fartlek training offers runners of all levels multiple benefits. These include: Improves fitness: Running at high intensity before dropping to a slower pace is widely accepted as providing multiple benefits to your body’s conditioning. Switching between low-intensity aerobic and high-intens