One study of this sort was recently performed by researchers at St. Mary’s University College in England and at East Stroudsburg University in Pennsylvania. Twenty student volunteers were asked to complete a workout consisting of 12 x 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 one. The researchers were able to gather additional information that provides 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.
Firstly, 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 suggest 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.
Secondly, the researchers observed that ratings of perceived exertion (RPE) steadily increased over the course of the workout even as sprint times held steady. On average, RPE was 10 on a 20-point scale after the third sprint and increased to 14 after the 12th sprint. This finding suggests that the subjects got a sense for how fatigued they should feel at any given point in the workout to avoid becoming totally exhausted before the workout was completed.
Finally, the researchers observed a negative correlation between the individual students’ rest times and their VO2max measurements. In other words, the more aerobically fit an individual student was, the less time he tended to rest between sprints. Since a higher VO2max does in fact enable one to recover faster after high-intensity exercise efforts, this observation suggests that individuals of various aerobic fitness levels are able to accurately sense their capabilities and make appropriate training decisions based on these feelings.
This study was published in the December 2009 edition of the Journal of Strength and Conditioning Research.
About The Author:
Matt Fitzgerald is the author of numerous books, including Racing Weight: How To Get Lean For Peak Performance (VeloPress, 2012). He is also a Training Intelligence Specialist for PEAR Sports. To learn more about Matt visit www.mattfitzgerald.org.