Fartlek Cardio to Improve Your Wind

If you’ve started mixing intervals into your cardio, good — that instinct is exactly right. Higher-intensity work is one of the best ways I know to build your engine. BUT most interval workouts turn cardio into rigid homework: 30 seconds on, 90 seconds off, watch the clock, repeat.

Except for the fartlek.

Yes, it’s a funny word. It’s Swedish, and it translates to “speed play.” (In the video I say it means “fun run” — wrong translation, but close enough!)

Here’s how it works: you pick a duration — say, 20 minutes — and inside that window you alternate between sprinting, jogging, and maybe just a little walking, entirely by feel. If you’ve ever been on a trail and thought “I’m going to sprint to that tree, then walk a bit, then jog awhile,” you’ve already done a fartlek. There’s no interval timer and no prescribed work-to-rest ratio. You sprint when you feel like sprinting, you back off when you need to, and the only thing you measure is the total time.

That’s what I love about it. It’s high-intensity cardio without the grim slog. It builds your wind — the ability to surge, recover, and surge again — which is what you actually use in real life, whether that’s a pickup game, a steep section of trail, or catching a bus.

A sneak preview (with apologies to Sweden)

We’re building the Stronger. Faster. Younger. app right now, and fartlek days are part of the cardio programming. This week the workout picker abbreviated “Total Body + Easy Fartlek” a little too aggressively:

We noticed. We’re… considering keeping it.

After all, our nutrition motto is beans & greens!

More previews of what we’re building coming soon. In the meantime — try a 20-minute fartlek this week. The first time you chase down a tree at a full sprint, you’ll remember why running used to be fun!