Interval Training Descriptors

Zach Snyder asked me to write about the descriptors you use for teaching percentages of maximum effort for use with interval training. For example, what does 80% (or 50, 60, 70, 90%) of maximum effort feel like? This question stems from page 130 of Athletic Development book.

Zach let me briefly explain the genesis of using verbal descriptors rather that actual percentages for the particular distance. Verbal descriptors are nothing more than indicators of perceived exertion that have been validated by Gunnar Borg, a Swedish researcher. It seemed to make sense, especially when I was working with team sport athletes who had no sense of pace even if I would have given them an exact number. They should know what 100% is, I tell them it is all out. How hard would all out effort be for 30 seconds? Then ask them to run what they think is 80% of that with the understanding that they have run 12, 16 or eighteen repetitions with a 30 second walk. Then I coach it, I do not just hold a stopwatch and blow a whistle. Closely observe how they a handle it. Probably in the first few sessions they will undershoot and run more within themselves than you would like. As they get into the swing of things then they come to understand the gradations of effort. Basically 70% is a pretty conversational pace if the work to rest ratio is 1:1. That is a good staring point. It is good to have descriptors for the various percentages of effort. The famous Hungarian distance coach Mihay Igloi used that system very effectively. I have borrowed that idea and change the descriptors based on the population. Generally the descriptors go something like this:

Easy – 60%

Medium Easy – 65% to 70%

Medium – 75%

Medium Hard – 80%

Hard – 85% to 90%

Competition of Game Effort – 95% to 100%