Workout of the Week: Ks For Days

If you’re training for longer races like half-marathons or marathons, it behooves you to do regular work at or around threshold intensity, which, according to renowned coach and exercise physiologist Jack Daniels, is the effort you can race at for 50-60 minutes. For simplicity’s sake, let’s say this is slower than your 10K pace but faster than you can go for a half-marathon. These workouts require a lot of focus while improving the physiological and psychological endurance you’ll need to race well at longer distances. One of my favorite threshold workouts is a bunch of 1-kilometer repeats with a short rest (30-60 seconds) in between intervals. We start at half-marathon pace if not a touch slower—better to start on the side of too slow than too fast—and get a little quicker as the workout goes on without ever going too crazy. Here are the details:

What: 8-15 x 1K (0.62 miles) with 30-60 seconds recovery between reps. Start at half-marathon pace for your first few intervals and let the pace gradually get a little faster as the workout progresses. At no point of the workout should you ever exceed 10K pace.

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: This is a great alternative to a traditional tempo run, it allows you to get in a big chunk of work at/around threshold intensity, and it’s mentally a little easier to break it up into intervals.

Where: This session is best done on a flat stretch of road or runnable trail but can also be completed on a track or treadmill.

When: This is a good go-to workout for marathoners and half-marathoners to do 3-4 times over the course of a 12-16 week training cycle. Start with 8 reps early in a training cycle and increase the number of reps and/or pace every few weeks as your fitness improves.