Comparison of Speed-based and Position-based Auditory Feedback in Eccentric Strength Training

Eccentric training, which involves muscle lengthening under tension, requires controlled movement speed to maximize effectiveness. However, muscle fatigue often leads to unintentional acceleration, reducing training effectiveness. This study proposes SpeedFB, a speed-based auditory feedback system that provides real-time auditory cues to regulate movement speed. Specifically, we developed a prototype system for eccentric biceps curls that employs a ``charging sound,'' inspired by sci-fi games, to provide feedback on movement speed. We conducted two experiments to evaluate the effectiveness of our system: (1) The first experiment compared SpeedFB with a numerical count method and a no-feedback condition. Results showed that SpeedFB effectively prevented acceleration and prolonged the eccentric phase. (2) The second experiment compared SpeedFB with a position-based feedback method (PositionFB). The results showed that SpeedFB promoted a more consistent movement duration, whereas PositionFB led to slower movements with increased variability. These findings suggest that speed-based auditory feedback is a promising approach for improving movement regulation and ensuring consistent eccentric training.