Workout of the Week: The 5 x 5 Fartlek

We’re nearing the end of cross-country season here in the U.S., and the fall road racing schedule will also be winding down over the next 3-4 weeks. One of my favorite all-purpose workouts to assign this time of year, whether you’re shredding grass, locking into a rhythm on the roads, or going back-n-forth between the two is the 5 x 5 Fartlek. Here are the details:

What: 5 x 5 minutes at 8K-10K effort/pace with 2:30 jogging recovery between reps. Note: To steal a line from one of my running heroes, former marathon world-record holder Steve Jones: “It’s the effort that matters on hard days.” That said, if you’re a number cruncher, this effort roughly equates to 5K pace + 15-20 seconds/mile—or, coming from the other end of things, it works out to around half-marathon pace minus 20-25 seconds/mile.

Warmup/Cooldown: Warm up before the workout with 15-30 minutes of easy running followed by a set of drills and 4-6 x 20-second strides (i.e., accelerate for 5 seconds, spend the next 10 seconds at near-top speed, and then gradually decelerate to a jog over the final 5 seconds. Catch your breath for 40-60 seconds and then repeat 3-5 more times). Cool down after the workout with 5-15 minutes of easy running.

Why: It’s really hard to fake your way through 25 minutes of work at this intensity. Nailing this simple-but-not-easy session will give your fitness a nice boost and also help you develop the mental toughness to keep running hard when you’d otherwise let yourself off the hook.

Where: Roads, trails, or grass are preferable for this one so you can work on adapting and adjusting your effort over different types of terrain.

When: This is a great workout to repeat a few times over the course of a training cycle as it helps build strength and confidence while also allowing you to compare efforts and track progress. It is a tough session so I wouldn’t recommend doing it within 7-10 days of a key race.