CHARGE

Found a bug? Please report it to me! I’d appreciate the help! CHARGE is a scientifically advanced data field developed as part of a Master Thesis. It analyzes the relationship between external load (Power) and internal load (Heart Rate) in real-time to provide deep insights into your aerobic efficiency and autonomic nervous system status. Key Features: Real-time Cardiac Drift Analysis: Uses a hybrid algorithm combining EWMA filters and linear regression to detect cardiac drift live during your ride. The system automatically calibrates your baseline between minute 10 and 30 of your activity. Aerobic Decoupling (Pw:Hr): Calculates long-term decoupling specifically for Zone 2 efforts, defined as 55% to 75% of your FTP. The algorithm aggregates data into 45-second blocks to ensure highly valid comparisons between the first and second half of your ride. Heart Rate Kinetics (Tau & Time Delay): Performs active "Step Response" tests. Press the Lap Button to arm the system. Once it detects a power jump of 50W, it records your physiological response for exactly 120 seconds. It then uses an advanced Non-Linear Least Squares (NLS) solver to fit an exponential model to your data, calculating Tau (the time constant of adaptation), the Step Amplitude (total HR increase), and the Time Delay (the lag before your heart rate starts to rise). Heart Rate Recovery (HRR): Automatically arms when your 30-second average power exceeds 85% of your FTP. Once your power drops into the recovery zone (below 55% FTP), it measures your heart rate drop over exactly 60 seconds. Aerobic Base Score: Tracks your long-term Zone 2 efficiency to monitor your aerobic fitness progress. To qualify for a score, your session must last at least 60 minutes. Comprehensive Efficiency Metrics: Displays Absolute Efficiency (W/HR), Normalized Efficiency Ratio (IF / %HRR) to make efforts comparable across different athletes. Full FIT File Support: All calculated metrics are written directly to your FIT file for post-ride analysis in Garmin Connect or 3rd party tools. Logged data includes: Cardiac Drift and Aerobic Decoupling. HR Kinetics (Tau) and Step Amplitude. Heart Rate Recovery Score. Aerobic Base Score. Efficiency Ratio and Joules/Beat. Usage Note: For the most accurate Decoupling and Base Score results, aim for steady-state endurance rides in Zone 2. For Kinetics testing, use the Lap button to signal the start of an interval and try to maintain a steady power output for at least two minutes.