Everyone has a story about why they started running. For some, it was part of conditioning during high school soccer practice. For others, it was their first step into fitness before graduating to sweat-drenched HIIT classes or hardcore HYROX competitions that combine weights and cardio. And for plenty of guys, running has always been the cheap, no-frills way to get out of the house, breathe fresh air, and clear their head. No matter the reason, most runners eventually start thinking about how to get better, faster, and stronger on their feet.
If running isn’t just a side step from your lifting session and you actually take it seriously, chances are you’ve followed a structured plan to improve your pace and get race-ready. But if structure isn’t your thing, you’ve probably been doing fartlek—an unstructured running workout that utilizes changes in pace and intensity to boost performance—without even realizing it.
To cover everything you need to know about fartlek and how to work it into your routine, we turned to professional ultra-runner, medical personal trainer, running coach, and sports nutritionist Yana Strese.
What Is Fartlek Running?
Fartlek literally translates from Swedish to “speed play.” It’s an unstructured style of running where you mix up speed and intensity instead of locking into one steady pace. Unlike traditional interval training, which alternates between prescribed high-intensity efforts and set recovery periods, fartlek is far more flexible.
“In an interval workout, you might do 6 × 800 m at 5K pace with 2-minute rest,” Strese says. “In fartlek, you decide on the go: maybe 2 minutes hard, 1 minute easy; or sprint to a lamp post, jog to the corner. This flexibility improves your ability to change gears, handle surges, and recover on the move—key skills for races, trails, or even team sports. Physiologically, you’re still training both your aerobic and anaerobic systems, but without the rigid timing.”
Why You Should Incorporate Fartlek
Structured running is essential when you’re training for a marathon or trail race, but it doesn’t need to define every run. Constantly chasing faster splits and cleaner form can get monotonous—and sometimes even suck the joy out of why you started running in the first place.
“Traditional intervals can feel like a test you’re either ‘passing’ or ‘failing,'” Strese says. “With fartlek, the effort is self-directed and often linked to landmarks (run hard to the next tree, jog to the bridge). This reframes ‘work’ as exploration.”
For Strese, who’s been running for years, that mental shift makes fartlek more enjoyable and sustainable. Instead of always grinding toward the next benchmark, it lets her and her clients run for the fun of it while still building fitness. “Instead of dreading a set of precise splits, you finish the run feeling accomplished and refreshed,” she says.
Beginner-Friendly Fartlek Workout
1. Warm Up
Start with 10 minutes of easy jogging to loosen your muscles and get into a rhythm.
2. Pick Your Markers
Choose landmarks or time intervals to guide your effort—run hard to the next streetlight and then jog to the next. Strese says beginners can start with fewer reps or shorter efforts.
3. Play With the Pace
The core of fartlek is mixing in faster efforts with recovery jogs. Run harder than your normal pace when you’re running to a marker, then ease back down until you’re ready to go again. A simple starter workout is 6 to 8 rounds of 1-minute comfortably hard runs followed by 1 minute of easy jogging.
4. Keep It Flexible
Unlike structured intervals, there’s no stopwatch, so adjust your speed based on how you feel. Push harder if you’ve got the energy, or ease off if your legs are heavy.
5. Cool Down
Finish with 5 to 10 minutes of easy running or walking, followed by light stretching.
Related: Should You Rotate Between Two Running Shoes? Here’s What Experts Say
Who Can Do Fartlek Training?
Whether you’re an athlete training for a race who needs a break from structured intervals, someone coming back from injury, or a beginner just trying to build a habit, fartlek training works for everyone.
“Because it’s based on effort rather than distance, you can adapt it to almost any activity: cycling, rowing, elliptical, even outdoor circuits,” Strese says. “For team-sport athletes, fartlek mimics the unpredictable stop-and-go demands of play. For people focused on fitness or fat loss, the alternating intensities can boost calorie burn and cardiovascular conditioning without the intimidation of a stopwatch or treadmill program.”
