Heart Rate Variability

Why It Matters

Heart Rate Variability (HRV) is one of the best indicators of overall longevity and nervous system health. It measures the variation in time between each heartbeat—higher variability indicates greater adaptability and resilience.

HRV is linked to:

  • Lower risk of cardiovascular disease

  • Better stress tolerance and autonomic nervous system health

  • Higher mitochondrial efficiency and recovery capacity

How To Measure It

  • Whoop


    WHOOP is one of the most advanced wearables for HRV tracking, measuring it continuously during the final stages of your sleep—when your body is most rested and free of movement-related interference. It uses HRV as a core input for its daily Recovery Score, helping users make informed decisions about training, stress, and recovery.

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  • Garmin

    Garmin tracks HRV overnight and provides insights via features like HRV Status, Body Battery, and Training Readiness (on newer models). While less focused on HRV than WHOOP, Garmin integrates it into broader training and recovery metrics, making it valuable for athletes seeking performance and longevity optimization.

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  • Oura Ring

    The Oura Ring shines in HRV tracking during sleep, capturing continuous nighttime HRV data with high precision through its finger-based sensors. It uses HRV to inform its Readiness Score, giving users daily insights into their recovery and stress levels for optimal longevity and performance decisions.

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