The Effect of Pedal Float on Power Output in Individual Cycling Performance

THE EFFECT OF PEDAL FLOAT ON POWER OUTPUT IN INDIVIDUAL CYCLING PERFORMANCE

Ossenbrink, B., Urbannek, T., Haff, G. G..
Midwestern State University, Wichita Falls, Texas

The purpose of this study was to investigate how 0, 5 and 10 degrees of rotational freedom on road cycling pedals affect performance during a 20 km time trial. Ten male and two female elite cyclists volunteered for participation in this study (age: 24.6 ± 6.7, height: 176.8 ± 7.5 cm, weight: 73.8 ± 9.1 kg, bodyfat: 9.1 ± 4.8 %, VO2max: 60.8 ± 7.8 ml.kg.min-1). The present investigation tested the subjects during 4 sessions using road bikes on a CompuTrainer ergometer (RacerMate, Seattle, USA). The first session included collection of biometric data and VO2max cycling testing. Session #2, #3 and #4 were 20 km individual time trials with a 500-meter incline at 9.5 km and 19.5 km. The pedal float was randomly assigned during session #2, #3 and #4. Subjects used 0°, 5° or 10° of pedal float. Performance parameters, peak and average power, peak and average velocity, peak and average heart rate and total time were measured with a Polar Heart Rate monitor (Polar, Kempele, Finland), PowerTap power meter (Cycleops, Madison, USA), and CompuTrainer ergometer (RacerMate, Seattle, USA). There was no significant difference (p > 0.05) between the three pedal float conditions for performance parameters. No significant difference was found comparing the heart rate at 9.5 km and 19.5 km between the float conditions. Only heart rate at 9.5 and 19.5 km was significantly higher at 19.5 km when compared to 9.5 km in the 0° pedal float condition (p=0.01) and 10° pedal float condition (p=0.03). In conclusion it is suggested that rotational freedom present at the pedal/shoe interface of road cycling pedals does not result in a decrease in individual cycling performance as measured by performance parameters power, velocity, heart rate and time during a 20 km time trial. Therefore, it is recommended that cyclists should select a pedal/shoe interface (float or no float) that minimizes the risk of overuse injury at the knee and which adapts the best to their pedal stroke.

Keywords: cycling, pedal float, time trial