When I was reaching the peak of my running abilities, I started keeping track of the total elapsed time of my speed sessions so that I could see what workouts seemed to pack the most punch regardless of the structure of the workout.

I discovered that, when looking at overall time— with recoveries included—divided by total distance, the best speed sessions tended to end up averaging close to marathon pace. Whether the speed portion consists of 200s, 400s or miles—when these are combined with the appropriate recovery—the elapsed time of the whole session is similar, and roughly equates to an appropriate 26.2-mile race pace.

These workouts, which focus as much on the recovery time as they do the speed, are often the most systematically-taxing speed sessions I’ve done or seen. Having tried to account for my own biases and other static, I’ve decided this probably isn’t a coincidence, and leads to useful lessons for all racers.

Honor The Rest Interval

Like most high-school runners of the late 20th century, much of my track work was reps of 200 to 800 meters with “a 200 jog” or some other similarly hazy rest interval. It soon became apparent, however, from reviewing the work of successful coaches that while practicing running fast is a necessary part of running faster in races, it’s also not enough on its own, and that the recovery interval should be as tightly controlled as the reps to optimize fitness gains. It was also obvious that a lot of runners avoid such workouts because they’re too difficult—more mentally than physically.

A lot of marathon-centric road racers do their best to hide from “real” speed work—anything faster than tempo pace—and pretty much anything involving pace discontinuities. Whether it’s the unique brand of discomfort, the flexible type of discipline required, or other factors, a lot of otherwise hardcore runners simply don’t like doing repetition-interval sessions.

track workout young men
photo: 101 Degrees West

Stamina and Economy

“Intervals” aim to expand what might be called your anaerobic reserve. These include repetitions lasting up to about five minutes and done at a pace you could hold for roughly 10 to 15 minutes at 100-percent effort. Learning to do these workouts right not only increases their effectiveness, but makes them less of a grim prospect.

In large part, such sessions are your primary defense against deteriorating in the last third or so of a short race. But done correctly, they allow you to run more economically over longer race distances as well. Unfortunately, most people never develop a concept of what “correctly” looks outside of hitting or bettering their target repetition paces.

Variation on a Marathon-Pace Theme

Joe Rubio, longtime coach of the HOKA Aggies and a 2:18 marathoner in the 1990s, recalls doing in/out 400s early in his training cycles in which he would alternate 5K pace with relatively aggressive “off” laps. “I’d go back and forth, no breaks, for 4 miles—think 70s and 90s [per 400m].” This works out to an average of 80 seconds/lap or 5:20/mile, which is about 2:20 marathon pace for the session as a whole.

Jack Youngren, head coach of the West Valley Track Club and a medical biochemist, also utilizes a 30-minute session of alternating “hard” (about 5K race pace) and “easy” running, with faster segments and recovery periods of varying length strung together in an unpredictable but precisely scripted manner to ensure that 5K pace can be maintained for 18 total minutes and that the overall pace for the half-hour is close to marathon pace. Because the pattern is unknown to the runners, and the transition from fast to easy running is signaled by a whistle blow, the workout has been termed “the Blind Obedience Fartlek.”

track workout fast young men
photo: 101 Degrees West

The Half-Half Repetition Workout

While these examples show it is possible to do a wide variety workouts that include three or so miles of faster running and enough slower running to yield marathon pace. But the simpler they are, the easier it is to get used to running them.

This led me to devise the half-half repetition workout. In these kinds of workouts, the total amount of running is about 3.5 miles. The rest interval is half as long as the reps, and run at half the speed—which means the recovery distance is one-fourth as long the reps.

Workout Examples

Consider a 20:50 5K runner (1:40 per 400m) aiming for a sub-3:30:00 first marathon. Her 3K pace is pegged at 1:36 per 400m. (If you don’t know your 3K pace, estimate it by multiplying your 5K pace by 0.96.) Here are two workout variations she could run:

  • The 10 × 400m @ 3K pace w/ 100 recovery @ 50% of 3K pace10 × 400 in 1:36 with 48-second 100m jogs produces a series of 500m “reps” in 2:24 each, making the average pace 7:40/mile or about 3:22:30 marathon pace.
  • The 3 × 1600m @ 5K pace w/ 400 recovery @ 50% of 5K paceThis workout is 3 × 1600m in 6:40 with 400m recoveries in 3:20. The total time per 2000m is 10:00, about 8:00/mile or 3:30 marathon pace.

You can set up rep/recovery schemes of 600m/150m (unwieldy on an outdoor track), 800m/200m, 1000m/250m or 1200m/300m. Aim for 3K pace or a little slower if doing reps up to 600m, but keep the clip at 5K race pace for anything longer.

You should warm-up and cool-down with 1 to 3 miles before and after these workouts.

track workout timing
photo: 101 Degrees West

It’s About Discipline

One can perhaps make a physiological argument for the inherent value of what amounts to a short, highly controlled fartlek session run at close to marathon pace. But the lasting value of doing sessions like these is that it instills discipline and standardizes your workouts not only session to session but from season to season, even from year to year.

If you’re primarily a marathoner and are doing a lot of interval workouts with a work-to-recovery time ratio of 1-to-1 or higher (remember, scheme here is 2:1 work/recovery ratio), you could probably stand to incorporate some of the strategies here.

Note, if you cheat by even a few seconds, you’re not going to teach your body exactly what you intend to. Don’t let the recoveries drift longer—if you have to slow down the reps to get three miles or so of fast running in, by all means do.

One of these per week, integrated into your existing plan, should see you make considerable fitness gains in a single training cycle.

Kevin Beck has written extensively for Running Times,Competitor, Triathlete, Men’s Fitness, Motiv Running, Marathon & Beyond, the New York Road Runners and elsewhere. The editor of Run Strong(2005) and the co-author of Young Runners at the Top(2017), Beck has coached high school cross country and adult athletes ranging from everyday marathoners to the occasional Olympian. The runner-up at the 2004 USATF 50K Road Championships, Beck holds personal bests of 14:58 for 5K, 51:32 for 10 miles, 1:08:29 for the half-marathon and 2:24:17 for the marathon.