Cross-Country Running - Tempo Speeds Should be Faster Than Traditionally Thought
Cross-Country Running - Tempo Speeds Should be Faster Than Traditionally Thought

Cross-Country Running - Tempo Speeds Should be Faster Than Traditionally Thought

Dick Moss

Tempo training has traditionally been an important component of most distance running programs. Also called "lactate threshold training" or (rather inaccurately) "anaerobic threshold training," it involves running at or slightly slower than your lactate threshold pace.

This pace is the point at which lactate in the blood begins to accumulate, causing rapid fatigue. It was thought that running for about 20 minutes at this pace was the best way to increase the speed at which lactate threshold occurred.

In practical terms, this speed it was generally considered to be 15 km race pace, or the running speed at which it starts to become difficult to talk (the "talk test"). That's because lactate threshold occurs at about the same point as your respiratory threshold.

It was thought that training at or just below this speed was the most effective way to raise the lactate threshold. And lots of good things happen when you increase the speed at lactate threshold--basically, it allows you to run at a faster pace before you start to fatigue.

However, new research has shown that running at the threshold itself is not the most effective method.

Why the Confusion?
Threshold pace running became popular based on the results of a 1982 study by Bertil Sjodin that showed significant improvement in lactate threshold after 14 weeks of once-weekly 20-minute runs at threshold pace. But in retrospect, this study exhibited problems including lack of a control group, problems in statistical interpretation, and measurement methods that we now know aren't reproducible.

New Research
New research has shown that the lactate threshold is more effectively improved by running at speeds that are faster than the threshold pace. That's because we now know that lactate threshold is most effectively improved through exposure to lactate. This exposure teaches the muscle fibres to more effectively clear lactat, and in fact to use it as a fuel. The faster we can clear lactate, the faster we can run before it starts to accumulate…and the higher our lactate threshold pace becomes.

Recommendations
In order to most effectively improve lactate threshold in a tempo-type workouts, athletes should run faster than threshold pace.

And what speeds are most effective? In fact, anywhere from two kilometer to ten kilometer race-pace (rather than the old 15km race pace). While any pace within this range is effective, 2km race pace (about 100% V02 max) is most efficient in terms of improvement-per-minute of training. This efficiency declines as the pace slows.

If your runners aren't good at estimating paces, have them use the old "talk test" as in traditional tempo training. However, as opposed to the traditional recommendation, in which they would run at slightly below the point at which they'd have difficulty talking, reverse this, and have them run at a pace that is faster than the speed at which talking becomes difficult.

Editor's Note
Are you kicking yourself because you think all those tempo runs you prescribed were wasted? Don't. In my experience, the pace most of my runners believed was at "threshold" was actually considerably faster. So those old tempo runs were probably exactly what they needed.


Reference: Owen Anderson (PhD), Lactate Liftoff, 2nd Edition, 2007. An eBook available from Running Research News. http://www.runningresearchnews.com

 

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