Fartlek, a Swedish term for “speed play,” is a training approach with no formal rules regarding intervals of varying speeds and intensities. It combines easy running with intervals of quicker running.
Unlike rigid interval workouts, fartlek sessions let athletes select when and how long to accelerate, often using landmarks—like lamp posts or hills—to guide pace changes. This flexibility trains both aerobic and anaerobic systems, improves mental adaptability, and mimics the variable demands of races with surges and terrain changes. Fartlek benefits include enhanced speed endurance, recovery ability, and enjoyment from breaking monotony. It’s a staple in running programs but can be adapted to cycling and swim workouts for varied intensity.
