
Fartlek intervals bring variety, unpredictability and race-day realism to your rides. But what is Fartlek, and how does it fit into cycling and triathlon plans? This guide breaks down Fartlek training, showing how to use it in Fartlek cycling training sessions, indoors or outdoors, and why smartly applied Fartlek training can sharpen pacing, recovery, and resilience for every level of athlete.