Tempo Runs… Real?
Tempo runs the real vs. unreal
Tempo runs have been popularized in training logs for many years now and are often used out of context and for the wrong reasons. This article will address some of the reasons runners misuse and misunderstand the point of a tempo run. I have referenced Jack Daniels, a renowned running coach and author of The Running Formula.
The misuse of the phrase is fed by two main sources: basic ignorance and the tendency of a dispirited runner to grab for the nearest handy excuse. Anyone who labels a race in which he doesn’t stick precisely to a predetermined pace a “tempo run” is invariably offering a ramshackle justification for a sub-par performance. The term seems to be particularly applied to races in which the athlete goes out hard and crashes harder. My favorite example is that of a friend who dropped out 21 miles into a marathon and, in a mitigating gesture, called the disappointing result a “tempo run.” Twenty-one miles at 10-mile race pace? I’m not surprised he had to quit.
The popularization of the tempo run also provides opportunities for sandbagging and psychological ploys. I’ve heard competitors mumble, “I’m just doing a tempo run,” seconds before commencing to hammer out a whopping PR.
Just Over Easy
So just for review, let’s see how the experts define the term. Also known as an anaerobic threshold (AT) run or lactate-threshold run, the tempo run was popularized by Jack Daniels, Ph.D., about a decade ago. Here’s his definition, taken from Daniels’ Running Formula (Human Kinetics): “A tempo run is nothing more than 20 minutes of steady running at threshold pace.” (He goes on to say that 20 minutes is ideal, but may be varied to suit the needs of a particular course.) Without getting too technical, threshold pace is the effort level just below which the body’s ability to clear lactate, a by-product of carbohydrate metabolism, can no longer keep up with lactate production. Daniels states that this pace is, for most people, about 25 to 30 seconds per mile slower than current 5K race pace.
Exercise physiologist and coach Pete Pfitzinger adds: “For very fit runners, the pace is between 15K and half-marathon race pace.” For those fond of using heart rate monitors, Daniels notes that tempo runs are done at 90% of maximum. However, most runners seem to find it easier to use running speed as a guide.
For those who have neither HRMs nor marked courses at their disposal, Daniels stresses that the effort associated with a tempo run should be “comfortably hard”—one that could be maintained for an hour in a race.
Maintaining a specific and consistent pace is the most important aspect of a tempo run. However, this doesn’t exclude variety in other respects, depending on a runner’s individual goals. Says Pfitzinger, “The tempo runs I use for my athletes most frequently are four to six miles at 15K to half-marathon race pace.” For marathoners, Pfitzinger prescribes up to nine miles at between half-marathon and marathon race pace, or a 13-mile run followed by five miles at between half-marathon and marathon pace. He will typically have his runners perform two of these workouts every three weeks during a marathon build-up. This is a sensible guideline; as the goal race approaches (but before tapering) the runner might want to increase the frequency to one tempo effort weekly.
Pfitzinger adds that not all competitors benefit equally from tempo runs. “Athletes racing from 15K on up to the marathon receive the most benefit from tempo runs because the physiological adaptations are most specific to the demands of those races,” he notes. “An improvement in lactate threshold is only a small benefit for a 5K race because that race is run well above lactate-threshold pace. Performance in races of 15K to the marathon, however, is determined primarily by the runner’s lactate-threshold pace.” Tempo runs, therefore, provide a direct and important benefit in longer races for runners at any level, from novice to elite veteran.
Variations on the AT theme
Daniels mentions another workout, “cruise intervals,” which are tempo runs interspersed at regular (say, one-mile or 10-minute) intervals by 30- to 60-second rest periods. This pattern diminishes the psychological difficulty of the workout while preserving the aerobic benefits, allows greater volume (five miles or even more for elite marathoners) and may help guard against excessive speed. He also recommends inserting periods of AT running into long runs—say, two 20-minute tempo runs bookending an easy one-hour run—something a marathoner might do bi-weekly in the latter stages of race preparation.
Of course, any coach would strongly discourage the “accidental” tempo run that results from melting down in the middle of a race. As for another practice that has become common, deliberately planning races as tempo runs, Pfitzinger is almost as disapproving. “I don’t like the idea of my runners giving anything short of 100% effort,” he opines, “and even if the plan was to go at tempo-run pace, any motivated runner would likely go too hard once the gun fires.”
Remember, the one real requirement of tempo running is that you stick to a steady, specific, planned pace. Beyond that you have many options. Of course, if you’re still unsure, you can always resort to the tongue-in-cheek prescription set forth by the Tahoe Mountain Milers: “Tempo run: Running to the beat of your favorite song should be done at least once a week.”