Every week, runners from Boulder to Budapest and everywhere in between head to the track in search of speed. Workouts consisting of repeats ranging anywhere from 200 meters to two miles are commonplace amongst elite athletes and age-group runners alike. More often than not, however, these sessions follow a predictably bland format: 10 x 400 meters at 85 seconds per lap, 6 x 800 meters at 3:00, 3 x 1 mile at 7:30, etc. You get the picture.

Don’t get me wrong, these standard track sessions are all great workouts, but they’re rather monotonous, and more often than not they’re not very race-specific, either, as many age-groupers head to the track and start hammering out intervals as hard as they can from the get-go.

One of my favorite, not-so-boring workouts is repeat kilometers, or “Ks” in runner-speak. Depending on the training focus of the athlete and where he or she is at in the training cycle, Ks can take many different forms and achieve a variety of different ends by manipulating paces, the number of repetitions and the recovery intervals in between.

Find a place for one of the following four workouts in your training program:

Cruise Ks

A close cousin of the tempo run, cruise intervals are essentially a sustained effort broken into smaller chunks with a short recovery period between repetitions. A bunch of one thousand meter reps (2-1/2 laps of the track) are a great way to get in some lactate threshold work without totally destroying yourself. Cruise intervals are an effective early-season strength workout for 5K-10K runners and an excellent alternative to the tempo run for half marathoners and marathoners. A sample cruise interval workout using Ks is 10 x 1K @ half-marathon pace (or a touch faster) with 30-60 seconds recovery between reps.

Race-Pace Ks

Exactly as the name implies, these Ks are runs at goal race-pace with 1:00 recovery between reps. This is a great workout to run about 10 days out from a goal 5K or 10K to give you the confidence that you’re ready to roll on race day. An example of a race-specific workout using Ks is 5 x 1K @ 5K race pace with 1:00 recovery between reps, or 8 x 1K at 10K race pace with 1:00 recovery between reps.

Alternating Ks

These Ks will keep you on your toes! Performing a session of 1-kilometer repeats alternating between two to to three different paces is a great (and fun!) way to stress a few systems in the same workout. For example, rather than doing a standard session of 8 x 1K @ 10K pace with 2:00 recovery between reps (still a great workout!), perform 8 x 1K, alternating between 5K pace and half marathon pace with 2 to 3 minutes recovery after the 5K-pace intervals and 1 to 2 minutes after the half-marathon-pace efforts. Or, try three to four sets of 3 x 1K with the first rep at half-marathon pace (followed by 1:00 recovery), the second at 10K pace (2:00 recovery), and the last at 5K pace, followed by 3-4 minutes recovery. For marathoners and half marathoners, 12-16  x 1K alternating between marathon pace and half-marathon pace with a short rest (30-60 seconds) between reps is a great way to improve your fatigue resistance and also develop a better sense of race rhythm.

Sit-n-Kick Ks

Perhaps my favorite variation of 1-kilometer repeats, sit-n-kick Ks are designed for 5K and 10K runners in order to help improve their finishing kick at the end of races. Take a standard set of repeat Ks, say 5 x 1K at 5K pace, and run the first 800 meters (2 laps of the track) at 5K race pace before changing gears for the final half lap and kicking home the final 200 meters. Or, for 10K runners doing 8-10 x 1K, run 600 meters at 10K pace and kick hard over the final 400. If you would normally take 2:00 rest between reps when running a workout of 1K reps at a consistent pace, add another 30 to 60 seconds if you add the gear-changing element into the mix.

Originally published on July 8, 2015. Updated on October 17, 2018.