Heart rate variability (HRV) is a measure of variation in time (milliseconds) between your heartbeats. HRV provides a snapshot of how your body is balancing between the two branches of your autonomic nervous system: your sympathetic and parasympathetic.
SNS and PSNS are both essential for recovery and performance. SNS is the branch that leads to the excitement in the body in stressful situations. They activate the adrenaline and noradrenaline hormones and prepare the body for stress. On the other hand, the parasympathetic nervous system works towards decreasing the heart rate and blood pressure. It helps in recovery after stressful events.
Having variation is good more! Variations show that the parasympathetic branch of the nervous system is performing well as a regulator. The adjustments of the two in the external and internal stimuli are what provide the variations.
These variations further tell ways to measure how training load, fatigue, and physiological stress may be affecting our body.
Research has developed ways in which HRV has predicted many health-related issues. From being able to know about stress to predict illness in athletes HRV has proved to be a solution for many out there.
HRV as a tool has been commandeered by the sports community as a recovery and training metric. HRV shows the ANS functioning and therefore is the major reason that it is being used in the sports world today. It has shown its worth and does so by not only identifying the periods of optimal training but also by monitor the recovery status and the potential overtraining. HRV guided training refers to training that is being done on the basis of the HRV score. For example, if the HRV of an athlete is normal or higher than normal then they can perform intense training exercises. Alternatively when it is below normal than doing less intensive exercise is recommended. Doing the pre-planned exercise on the other hand doesn’t cater to your body needs as you are prescribed to do training without your health taken into consideration. This not only affects the performance of the athlete but may also lead to injury.
HRV guided training is said to be more beneficial than the other as it improves aerobic performance.
Normal HRV can range anywhere from below 20 to over 200 milliseconds, depending on various factors such as age, gender, physical fitness, and genetics.
HRV levels that are high or slightly higher than your normal range tend to be signs of a good recovery. A higher HRV may be the result of:
HRV levels that are lower than your normal range are signs of excessive strain on the body. Lower HRV may be the result of:
Note: naturally, after a hard workout, your HRV will likely decline. As you recover, your HRV should rebound. If it doesn't return to your baseline or takes an extended period, this can be an indication that you’re training too often or too hard.