Relationships between Muscle Activity and Autonomic Regulation during Cycling with a Torque-Assisted Bicycle

For customizing the assistance scheme of a torque-assisted bicycle, we estimated physical activity during cycling with ECG and surface EMG for the circuit including a steep uphill section near the middle and compared it with the vehicle data. Using the respiratory-sinus-arrhythmia-related power ratio in the fluctuation of the R-R interval, pr_RSA and a muscular fatigue index, we classified physical activity into four groups for each trial. Results showed that the assist enlarged pr_RSA but did not sufficiently support muscular fatigue