Performance stability in simultaneous tasks of pedalling and reaction time

The purpose of the study was to examine the within-subject variability in h eart rate, pedal rate, choice reaction time, and error rate during simultan eous tasks of cycling and reaction time. Students in physical education cla sses exercised a 10-min. submaximal cycloergometer test at a relative power output corresponding to 60% of their own maximal aerobic power, in a repli cation procedure. Concomitantly, the subjects performed a 2-choice reaction time task from Min. 3 of the exercise bout. No significant differences (p> .05) were found between the individual means in the tests for the diverse p arameters. The total intraindividual variability averaged 1.3% for heart ra te, 2.2% for pedal rate, and 13.3% for choice reaction rime. Because wide w ithin-subject. variability was observed (from 7.7 to 16.7%), the reliabilit y of choice reaction rime was low. These data suggest that it is necessary to quantify more accurately the intraindividual differences of reaction tim e measures for the interpretation of exercise-changes in cognitive function ing.