Exploring the Relationship Between Heart Rate Variability (HRV), Training Load, and Exercise Performance

Heart rate variability (HRV) is a measure of the variation in time between each heartbeat. It is an indirect and ubiquitous biomarker of performance readiness and recovery measured by most consumer-grade wearable fitness trackers. However, there is little documented on the relationship between HRV, training load, and performance measures in the Real-World. Whoop wrist-worn activity trackers have been validated against the gold-standard Electrocardiography (ECG) for HRV and HR measurements. Whoop leverages photoplethysmography (PPG) technology to continuously track (HR, HRV, respiratory rate, energy expenditure) and provides, daily, individual insights, trends, and coaching to improve strain, sleep, and recovery. Research has demonstrated that heart rate variability (HRV) guided training may be more optimal compared to predetermined training for aerobic exercise improvements. The purpose of this study is to assess the feasibility of providing personalized training recommendations based on HRV measured by a consumer-grade wearable (Whoop) in a real-world setting to better understand the HRV relationship with performance.