This variation results from the interaction between the cardiovascular system and the autonomic nervous system (ANS), which consists of two main branches: the sympathetic (SNS) and the parasympathetic (PNS) branch. The SNS predominates in states of physical activity, stress or anxiety, while the PNS predominates in states of relaxation. These two branches are in constant interaction, and in a way, HRV reflects the balance between these systems and acts as an indicator of how the body responds to stress—whether from training, work, caffeine, lack of sleep, or other life stressors.

Since the capacity to handle stress is limited, it can be useful to keep track of it. For athletes, strategies to control the amount of stress and recovery are key to facilitate the adaptation to training, ameliorate performance and prevent problems associated with overtraining. Measuring HRV, together with other lifestyle variables such as sleep metrics or recovery strategies, can help identify when the body is primed to train and when it would benefit from resting. Over longer periods, it can also help to determine whether a training plan is supporting progress or it may be leading to injury or burnout.

What I can help you with:

• Understand what HRV is and how to interpret it

• Reviewing and making sense of your data (HRV, sleep, training, subjective states, amongst others).

• Discussing training load to support adaptation and recovery

• Exploring lifestyle habits for long-term well-being