Changes

A tempo run, sometimes called a threshold run, is a common part of many training programs as coaches believe it is an effective way of improving lactate clearance. However, the science indicates that tempo paced runs should be avoided in favor of other paces. Tempo pace represents the no man's land between [[Long Run| Long Slow Distance]] and [[High Intensity Interval Training]]. They are too fast to be long, and too slow to be intense. They can improve performance in the untrained, but not as well as other types of training and so they are the least effective form of training. In fact, for highly trained runners there is evidence that Tempo Runs may actually be counterproductive. While there are claims that Tempo Runs have benefits for [[Mental fortitude]] this is not supported by the science that has looked at race performance. Note that performing intervals at Tempo, Threshold, or other sub-maximum effort can be considered [[Medium Intensity High Volume Intervals]] rather than a tempo run, which is typically continuous.

A Tempo Run intended to be run at or near the pace corresponding to the [[Lactate Threshold]]<ref name="Lifehacker2016"/><ref name="RunnersWorldWhatIs"/>. Lactate Threshold can be thought of as the transition from mostly aerobic to mostly anaerobic metabolism. In well trained athletes, paces below the Lactate Threshold can be kept up for prolonged periods (several hours), where paces about the Lactate Threshold typically cannot be maintained for more than an hour. The specific definitions vary a little, as it's tough to measure Lactate Threshold, more properly called "Maximum Lactate Steady State" or MLSS (See [[Lactate Threshold]] for more details.) Some example definitions:* Jack Daniels defines Threshold Pace as 83-88% of [[VO2max|V̇O₂max]], or 88-92% of your pace at [[VO2max|V̇O₂max]], or 88-92% of [[Maximum Heart Rate]], which he intends to be MLSS pace<ref name="JackDaniels2015"/>.* The [[FIRST]] training plans use a pace slightly slower than 10K pace or marathon pace.* The [[Hanson| Hanson's Marathon Method]] uses marathon pace for tempo runs.

* Tempo runs can improve performance in untrained subjects<ref name="Denis-1982"/><ref name="Denis-1984"/><ref name="Londeree-1997"/>. However , these studies did not compare how effective tempo runs are over other forms of training. * A study of 9 experienced recreational masters runners showed a dramatic improvement (50%) in time to exhaustion at Lactate Threshold after interval training at Lactate Threshold pace<ref name="Billat-2004"/>. The runners had an average half marathon time of 83 minutes (+/-5), but had never performed any form of speedwork. Their average training before the study was five runs per week for an average of 65 minutes at 12.4 KPH (7:36 min/mile). The study lasted for 6 weeks, with 2 tempo paced interval sessions replacing 2 of the slower paced runs per week. One session was 3 intervals of 10 minutes each, the second 2 intervals of 15 minutes. Each week the shorter and longer intervals were lengthened by 2 and 3 minutes respectively. After training [[VO2max|V̇O₂max]] increased 3.6% and Velocity at Lactate Threshold increased 4.2% (13.8 to 15.2 KPH, or 7:00 to 6:21). More impressively, the time to exhaustion at Lactate Threshold pace increased by a massive 50% from an average of 44 minutes before to 63 minutes after training. Unfortunately , the study did not include any form of controls to know how much familiarity with the testing procedure influenced the results, nor was there any comparison with other forms of training such as [[High Intensity Interval Training]].

* A 2007 randomly assigned 12 sub-elite 5K & cross -country runners to one of two training programs<ref name="Esteve-Lanao-2007"/>. The Z1 program had 80% LSD, 10% Tempo, and 10% HIIT, whereas the Z2 program had 65% LSD, 25% Tempo, and 10% HIIT. The Z1 group that did less time at Tempo pace improved their race performance more than the Z2 group. (Their simulated 10K times improved 35 seconds more, 157 second improvement rather than 121 second improvement.)