Consider the specific example of the standard recovery durations used in speed interval workouts. Exercise scientists like to blather about the physiological rationale for the work/rest ratios of 1:2 €“1:3 that are typically used in such workouts (e.g., 12 Ã— 400 m in 75 seconds with 2:30 jog recoveries), but this rationale was unknown at the time this standard was established. Runners discovered it by feel, as the minimum amount of rest time needed to enable them to complete an appropriate total number of speed intervals (this appropriate number also being established by feel) without a decline in performance. A very interesting study demonstrating how this process worked was performed by researchers at St. Mary’s University College in England and at East Stroudsburg University in Pennsylvania.1 Twenty student volunteers were asked to complete a workout consisting of 12 Ã— 30 second sprints on four separate occasions. They were instructed to rest just long enough after each sprint to perform at the same level in the next. This had to be done entirely by feel, as the subjects were not given access to external timepieces. In general, the students succeeded very well in maintaining their performance through all 12 sprints in each of the four trials. That is, in most cases the subjects ran just as fast in sprint number 12 as they did in sprint number 1. The researchers were able to gather additional information that provided some insight into how the students were able to use body awareness to accurately determine how long they needed to rest between sprints to maintain performance. First, the average amount of rest time taken between sprints was not the same in all four trials. Instead, it varied from one trial to the next. But the amount of variation between individuals within each trial steadily decreased from trial to trial. In other words, as a group the subjects moved toward resting for a similar amount of time between sprints. These patterns suggested that a learning process was at work. The students unconsciously experimented with different amounts of rest and gradually moved toward a consistent amount that represented the true minimum amount of time needed to maintain performance.