Crossfitters like to train a lot, sometimes even too much and the mere perception of tiredness or stress is not enough to evaluate and manage their level of stress and the consequent recovery, but it is better to measure objective parameters such as your HRV. And you know, the heart never lies.
Information is knowledge, and big tech companies know how important it is to collect and track data. When it comes to your health, it is now easy to measure and track all kinds of information. In the comfort of our homes we can check our weight, blood pressure, number of steps, calories, heart rate and blood sugar. Recently some researchers have started using an interesting marker for resilience and behavioral flexibility. It’s called heart rate variability (HRV).
Have you ever wondered what the health impact of a class or a slightly heavy WOD was? And if you train every day, how do you know when it’s time to recover and stop? Is there anything you can do today to improve your ability to perform better in the future? HRV could be the data that helps you answer these questions.
HRV is simply a measure of the variation in time between each heartbeat. This variation is controlled by a primitive part of the nervous system called the autonomic nervous system (ANS). It works independently of our desire and regulates our heart rate, blood pressure, breathing and digestion, among other things. The ANS is broken down into two large components, the sympathetic and parasympathetic nervous system, also known as the fight or flight mechanism and relaxation response.
The brain is constantly processing information in a region called the hypothalamus. The hypothalamus, through the ANS, sends signals to the rest of the body to both stimulate and relax various functions. It responds not only to a poor night’s sleep, or that acidic interaction with your boss, but also the exciting news that you got engaged, or that delicious healthy meal you ate for lunch. Our body handles all kinds of stimuli and life goes on. However, if we have persistent cues such as stress, poor sleep, unhealthy diet, dysfunctional relationships, isolation or loneliness, and lack of exercise, this balance could be disrupted and your fight or flight response can turn into overdrive.
HRV is an interesting and non-invasive way to identify these ANS imbalances. If a person’s system is more in fight or flight mode, the variation between successive heartbeats is low. If one is in a more relaxed state, the variation between beats is high. In other words, the healthier the ANS is, the faster you’ll be able to shift gears, demonstrating greater resilience and flexibility. Over the past few decades, research has shown a relationship between low HRV and worsening of depression or anxiety. Low HRV is also associated with an increased risk of death and cardiovascular disease.
Given that the fight-flight state is strongly influenced by stress and that every workout is in fact a stress for the body, when you train too much, the HRV variations indicate if you are still in an optimal state or it is better to give yourself a calmed down.
People who have high HRV may have greater cardiovascular fitness and be more resistant to stress. HRV can also provide personal feedback on your lifestyle and help motivate those who are considering taking steps to a healthier life.
High HRV means that you are managing stress, any type of stress, optimally. It is fascinating to see how HRV changes when one gains greater awareness, perhaps through meditation, sleep and above all calibrated activity. For those who love data and numbers, this can be a nice way to keep track of how the nervous system reacts not only to the environment, but also to emotions, thoughts and feelings.
The gold standard is to analyze a long strip of an EKG, but in recent years, several companies have launched apps and heart rate monitors that do something similar. The accuracy of these methods is still under scrutiny, but the technology is improving substantially.
The easiest and cheapest way to check HRV is to buy a chest strap heart rate monitor and download a free app like Elite HRV , which is the same one I’ve been using for at least 5 years, to analyze the data. The chest strap monitor tends to be more accurate than wrist or finger devices, I use a Polar H10 but other models are just as good too. Check your HRV in the morning after waking up, a couple of times a week, and monitor for changes as you incorporate healthier interventions.
In addition to controlling stress and taking appropriate countermeasures right away, HRV monitoring can be an excellent tool to motivate behavioral change for some. HRV measurements can help create greater awareness of how you live and think and how your behavior and workouts affect your nervous system and body functions.
While it obviously can’t help you avoid stress, it could help you understand how to respond to stress in a healthier way. The important thing is to consider that we are talking about a measurement method and that as such it must be interpreted and contextualized.