Change in pace during time trials in relation to hazard score

Abstract

Background: Pacing strategies are developed to avoid critical homeostatic disturbances. These disturbances can be monitored using the Rating of Perceived Exertion (RPE) scale. To maintain homeostasis and have optimal rate of increase in RPE athletes compute a ?hazard? score to determine whether or not it?s time to increase or decrease speed. The purpose of this study was to determine if the integration of momentary RPE and percent distance remaining (Hazard Score) explain these changes that can occur in pace. Methods: Eleven cyclists performed a maximal exercise test and five 10km time trials (TT). Two trials were for habituation and to obtain a baseline pace. Pace was manipulated for the first 2km of the three subsequent randomized experimental TTs, after which the remaining distance was completed as fast as possible. RPE, HR, power output (PO), and blood lactate concentration was measured. Results: Hazard Scores between each trial were significant (p<0.05). Hazard Scores of less than 1.0 indicated an increase in PO, whereas scores of greater than 3.0 indicated a decrease in PO. Conclusion: The Hazard Score seems to predict change in pace. This finding may become a helpful tool in terms of understanding how humans regulate their behavior during intense activity.