Heart rate (HR) is the number of heartbeats per minute, whereas heart rate variability (HRV) is the fluctuation in time between adjacent heartbeats. Let me illustrate: imagine a healthy individual with a HR of 60bpm. It is unlikely that this individual has one beat per second (60 seconds, 60 beats). Instead, the difference between two beats will be constantly changing, and will be something like 0.76s, 0.89s, 0.91s, 1.06s, etc., as represented in the picture below.
This change in the timing of heart rate beats, or what we call HRV, results from the interaction between the cardiovascular system and the nervous system. More specifically, the HR is regulated by a nervous system called the autonomic nervous system (ANS), which is characterised by having two 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 need to be in balance for the body to function efficiently.
HRV serves as an indicator of ANS balance (or lack of it!) because in the face of a stressor, the activity of the ANS changes to regulate body functions and this change is reflected in HRV. Stress can come from different sources such as exercise, caffeine, medicine, alcohol or food intake, to name a few, and HRV is a continuous feedback of the state of our body and its capacity to handle these inputs.
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. HRV can indicate when the body is primed to take on strain and when it would benefit from some rest. Over longer periods, it can also help to determine whether a training plan is making the athlete stronger or whether it is creating too much strain and will lead to injury or burnout.
NeuroAthleta’s HRV services involve:
Do you have questions about what HRV is? Or why is it useful?
Do you want to look at your data and understand it?
Not sure how to "improve" your HRV?
You can book a consultation (online or face-to-face options).
HRV-Guided Training (General)
Do you want to use HRV to guide your training? NeuroAthleta offers a phone app that recommends training intensity based on HRV, Resting HR and Mood & Fatigue Scales. The system automatically recommend to train "High intensity", "Low intensity" or "Rest", which will be explained to you. Access to the app is based on a subscription of 6e/month.
HRV-Guided Training (Tailored)
NeuroAthleta also offers a phone app that recommends a workout program based on your goals and following your HRV, Resting HR and Mood & Fatigue Scales. The system provides tailored workouts (if you want to improve endurance, for example, the workouts will be different than if you want to improve sprinting). Contact us, tell us your goals and we will match you to the program. Access to the app is based on a subscription: 15e/month.