Heart Rate Variability DFA a1: From Lab to Consumer Exercise Prescription and Monitoring.

Detecting exercise intensity thresholds is key for optimizing endurance training prescriptions for performance and recovery. Over the past several years an index of heart rate variability representing fractal correlation properties (DFA a1) has been investigated with respect to exercise intensity threshold demarcation and durability. We intend to show that sufficient data has accumulated to recommend it for widespread consumer use in tested populations. Summary: Validated consumer hardware, software, along with strong study results, support using DFA a1 monitoring to evaluate training zones and durability.