Polar Training Load Pro Alternative

Polar Training Load Pro splits training load into three dimensions: Cardio Load (internal load from heart rate using TRIMP — Training Impulse methodology), Muscle Load (external load from accelerometer-based movement analysis), and Perceived Load (session RPE — your subjective effort rating multiplied by duration). It displays 28-day load distribution across all three dimensions with a traffic light system: Detraining, Maintaining, Productive, or Overreaching. This three-dimensional model is one of the most comprehensive load frameworks available on any consumer wearable, capturing both what your body experienced internally and the mechanical stress on muscles and joints.