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Managing the Tempo Run with Cruise Intervals: Georgetown 400s

Managing the tempo run: One of the most essential, yet most challenging workouts for runners to do correctly is the tempo run.  Whether it be lack of long stretches of flat terrain without stoplights, high heat, or the inability of the athlete to run at or near their lactate threshold without going over it, the tempo run is often a frustrating experience for athlete and coach alike.  

Athletes tend to either run too fast or too slow, essentially losing the benefits of the workout – to build endurance and increase lactate threshold by working in or just below that specific heart rate zone.  While heart rate monitors can be helpful in learning what tempo effort should feel like, not all athletes have access to such technology and most need to take a stepping stone approach to be able to handle a standard 20 minute tempo run. 

Cruise Intervals: One means of preparing athletes for continuous tempo efforts while producing similar stimulus is breaking the tempo efforts down into shorter, more manageable cruise intervals.  Cruise intervals allow the athlete to get in the desired volume of quality running, while providing regular feedback about pace.  In fact, cruise intervals often provide opportunities to cover more ground than the athlete otherwise could at the same pace if running continuously.

Georgetown 400s: One of my favorite cruise interval workouts is known as Georgetown 400s.  Georgetown 400s get their name from the former Georgetown University middle distance program notorious for transforming athletes with shorter distance speed into mid-distance superstars.  When they started, many of the athletes could not do a 4 mile tempo run so their coach, Francis Gagliano, had them start doing short cruise intervals to help build their stamina.  They already had the speed.  They just needed to learn to extend it.  Georgetown 400s helped them blend their speed with endurance and the results were astounding.

Georgetown 400s are run in the outside lane of the track.  You begin each interval at the outside lane stagger where you would start if you were starting the 400m dash in the outside lane.  Run the entire 400m interval in the outside lane until you cross the finish line. 

Track dimensions w/ 400m stagger.  Modified image from

Recovery: Your recovery is simply the time that it takes you to walk/jog from the finish line in the outside lane until you get to the start of the outside lane stagger (roughly 30-45 seconds).  Then start again.  

Because cruise intervals are shorter than a typical tempo run, to get the same stimulus they are usually a few seconds per mile faster than threshold pace, but not as fast as traditional VO2 max interval pace.  What makes them challenging is that the rest intervals are shorter than between VO2 max intervals - usually about half the time it takes you to run the cruise interval.

While this pace will seem slow compared to what most people typically do when they run intervals on the track, the goal is to gradually fatigue the body and still run a few more intervals at threshold pace while fatigued. 

You want to finish this workout feeling like you could do at least two more at the same pace.

Start with a 15-20 minute warm up of easy running and drills, then do 6-8x400m at cruise interval pace with the walk/jog recovery from the finish line to the lane 8 stagger.  Then cool down with an easy jog for 15-20 minutes.  

Pace: To determine your cruise interval pace, use the McMillan Running Calculator.  

For example, an 18:09 5K runner training to run 17:30 for 5K, would run Georgetown 400s at approximately 1:29 to 1:31 per lap.  

Please see the paces below from the McMillan Running Calculator for further reference:

Stamina and cruise interval paces for an 18:00 5K runner based on the McMillan Running Calculator

Do this work out once every two weeks.  Add 2x400m intervals each time that you do it.  Soon, you will be doing more than 5K (12.5x400m) worth of intervals at threshold pace.  This builds stamina and your ability to run close to race pace without breaking down.

I've known runners (800m runners to ultramarathoners) who have built up to 40x Georgetown 400s by simply adding one or two intervals per week.  This workout builds stamina and helps athletes stay on pace which isn't always possible if you are trying to do a tempo run on a busy road or trail.  I've personally used them in my own training for marathons and ultramarathons and I have found them to be beneficial for the athletes with whom I work.  

Injury prevention: One of the advantages of Georgetown 400s is that by running in the outside lane you can often avoid the congestion of the inside lane while putting less stress on the inside and outside of your legs by not turning so tightly. 

Practice fueling: An additional benefit to cruise intervals is that they provide a means of practicing fueling and hydrating while on the run without having to carry a bottle or drop one off hoping to find it when you get there.  By simply placing a water bottle with water or an electrolyte drink on the outside of the track near the finish line you can take a swig or two between intervals.  This will not only make the workout more manageable in the heat, it will also help you prepare to fuel during your upcoming race

Building up: Naturally, if you are getting tired of quarters or simply want to switch things up, you can do the same thing with 800s, 1000s, 1200s, etc. Just follow the paces prescribed in the calculator for cruise interval (see example above) and give yourself approximately half the total run time in recovery before starting the next interval.  

Make it a fartlek: If a track is not available, you can do cruise intervals as a fartlek by running 6-8 x 2 minutes at tempo interval pace/effort (comfortably hard) and then jog half the time that you ran as recovery between intervals. Increase the number of fartlek intervals by 2-4 each time that you do it.  

Variations: As your training progresses and your stamina increases, you can do variations of this workout by adding some speed intervals to the end of the workout.  For example, after running 16x400m at Cruise Interval Pace, run 4x200m at speed pace (roughly mile pace) with a 200m jog recovery.  

Jacob Puzey is an IAAF & USATF certified endurance running coach who helps athletes of all ages and abilities from all over the world to reach new heights in their running performance.  If you are interested in working with Coach Jacob Puzey, please visit