In Reply To:
"Threshold is a subset of Tempo. All threshold runs are tempo runs, but not all tempo runs are threshold runs. "
I'm using Jack Daniel's terminolgy. Since he is the one who popularized it, I'll give him the benefit of the doubt:
http://64.233.169.104/...amp;client=firefox-a "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."
No offense but you are really not using Daniel's terminology. Neither is Beck. If you read Daniels' book, you'll see that he almost always speaks about threshold pace, not tempo pace. He does occasionally use the two words interchangeably but when he does strictly address the subject of "tempo" runs he clearly distinguishes them.
From Daniels Running Formula, Second Edition p. 113
"
Many coaches and runners do longer tempo runs at slower than true threshold pace, and this can yield positive results... In any case, I believe in the benefits of tempo runs that are longer than 20 minutes and have designed two tables that alter the speed of the run as dictated by duration"
As much as I respect Daniels, he did not invent the tempo run. I've heard enough elites talk about their 8 and 10 mile tempo runs to realize that the word itself has many interpretations. "Lactate Threshold" has only one meaning, however and is a much better term to use to describe the specific pace Daniels talks about. I suppose that's why he uses it.