What Exactly is a Tempo Run?
The T-word describes a specific, and very useful, workout
By Kevin Beck
As featured in the December 1999 issue of Running Times Magazine
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.
Simple enough. But troll the Internet for definitions and you will find statements such as the following: