Malterer, K. R., Foster, C., de Konig, J. J., Bischel, S., Krause, F. Menke, M., Rodriguez-Marroyo, J., Thiel, C., & Porcari, J. P. (2012). Decision-making relative to pacing strategy: Test of the hazard score hypothesis. Presentation 1437 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.

"Performance in any physically demanding task depends on a motor template and feedback regarding how the task is affecting the body. The ‘language’ of this feedback is the rating of perceived exertion (RPE). Previous evidence from our laboratory suggests that RPE x the % of distance remaining, the Hazard Score (HS), determines whether the athlete speeds up or slows down."

This study assessed if a Hazard Score predicts changes in running velocity during individual 3 Km time-trials. Well-trained, task-habituated Ss (N=12), completed three 3-Km running time-trials with individual starting times to discourage drafting/pacing off other runners. Changes in momentary running velocity vs. a Hazard Score were computed every 200 m by comparing the running velocity immediately (100 m) before providing a RPE score vs. the running velocity immediately (100 m) after the RPE score, to test the hypothesis that a Hazard Score >3 indicates deceleration and <1.5 indicates acceleration.

Regression analysis of a total of 34 3 Km time-trials (469 observations), revealed a regression curve predicting acceleration with a Hazard Score <1.5 and deceleration with a Hazard Score >3.5.

Implication. A Hazard Score based on ratings of perceived exertion may be a tool for understanding how humans regulate energy expenditure during exercise.

Return to Table of Contents for this issue.