How Data Can Capture Recovery: The Case for Heart Rate Variability

Heart rate variability (HRV) is a proxy of physiological stress, capturing autonomic nervous system responses to training and other stressors. As such, a vast body of literature has investigated the impact of acute and chronic stressors on HRV. Technological advancements such as mobile apps and wearables able to capture HRV data in more practical settings have further pushed the adoption and use of HRV analysis. In this chapter, we cover the physiological underpinnings of HRV analysis and discuss metrics and their relation to acute and longer-term stressors and in the context of training periodization and planning. Finally, we provide practical advice on validated technologies and best practices for practitioners interested in using HRV analysis to capture individual responses to training and lifestyle stressors.