Physiological Characteristics of the Preferred Transition Speed in Racewalkers

Purpose: The preferred transition speed (PTS) at which humans change their gait from walking to running was found to be lower than their energetically optimal transition speed (EOTS). This phenomenon has not been examined in racewalkers. The purpose of this study was to evaluate the PTS and the EOTS in racewalkers compared with controls. Methods: Eleven racewalkers and 13 control subjects participated in this study. Subjects arrived at the laboratory on three occasions. Visit I: determination of PTS. Subjects walked at a slow speed that was increased by 0.2 km[middle dot]h-1 every 30 s until they felt it was easier to run. Then, subjects ran at a high speed and the treadmill speed was reduced by 0.2 km[middle dot]h-1 every 30 s until they felt it was easier to walk. Visits II and III: subjects walked and ran at PTS - 1 km[middle dot]h-1, PTS - 0.5 km[middle dot]h-1, PTS, PTS + 0.5 km[middle dot]h-1, and PTS + 1 km[middle dot]h-1. At each stage, physiological measurements were recorded. Results: PTS was 7.33 +/- 0.33 km[middle dot]h-1 in controls and 8.20 +/- 0.54 km[middle dot]h-1 in racewalkers (P < 0.001), and EOTS was 8.00 +/- 0.48 km[middle dot]h-1 in controls and 8.46 +/- 0.55 km[middle dot]h-1 in racewalkers (P = 0.039). There was a trend for a smaller difference between PTS and EOTS in racewalkers. V[spacing dot above]O2 was higher during running at the PTS in both groups (F1, 22 = 5.972, P = 0.023), and there was a trend for a group interaction (F1, 22 = 3.442, P = 0.077). HR and V[spacing dot above]E were higher at the PTS in racewalkers compared with controls. Conclusion: Racewalkers have a higher PTS and EOTS compared with controls. There is a trend for the difference between the PTS and the EOTS to be smaller in racewalkers compared with controls.