Every week, runners from Boulder to Budapest head to the track in search of speed. Elites and age-groupers circle the oval in repeats ranging from 200 meters to two miles. More often than not, however, these sessions follow a predictably bland format: 10 x 400 meters, 6 x 800 meters, 3 x 1 mile, etc. You get the picture.

Don’t get me wrong, these standard track sessions are all great workouts, but they’re rather monotonous. One of my favorite, not-so-boring workouts is repeat kilometers, or “Ks” in runner-speak. Right out of the gun they are different as they don’t start and end at the same place: 1,000m requires 2 and half laps of a 400m track.

They’re also a nice moderately-long distance for playing with different purposes and strategies. 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.

Spice up your next speed work session by finding a place for one of the following four workouts:

woman running intervals on track
photo: 101 Degrees West

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 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 a relatively short 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 1:00–2:00 recovery between reps.

checking splits interval workout
photo: 101 Degrees West

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 way to stress a few systems in the same workout—and adds fun.

For example: Run 8 x 1K, alternating between 5K pace and half marathon pace on each repeat. Take 2–3 minutes recovery after the 5K-pace intervals and 1–2 minutes after the half-marathon-pace efforts.

Or, try descending pace sets: Run 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. Take a 3–4 minute recovery and repeat the set 3–4 times.

For marathoners and half marathoners, try 12–16 x 1K, alternating between marathon pace and half-marathon pace with a short rest (30–60 seconds) between reps. This is a great way to improve your fatigue resistance and develop a better sense of race rhythm.

young men running intervals on a track
photo: 101 Degrees West

Sit-n-Kick Ks

Perhaps my favorite variation of 1-kilometer repeats, sit-n-kick Ks are designed to help 5K and 10K runners improve their finishing kick at the end of races.

Take a standard set of repeat Ks, say 5 x 1K at 5K pace, but rather than maintaining a steady pace throughout, run the first 800 meters (2 laps of the track) at 5K race pace, then change gears and kick home for the final 200 meters.

Or 10K runners doing 8–10 x 1K can run 600 meters (1.5 laps) at 10K pace, then  kick hard over the final 400 meters.

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.

Updated from an article originally published on July 2015.