The way we feel and how we perform during various activities depends on a lot of different factors. No individual would have the same heart rate all the time, and this phenomenon is described as heart rate variability (HRV).
We have all heard about and seen many different heart rate monitors used by athletes and fitness professionals. And they might have helped some of us in tracking their HRV as well.
HRV is important
The autonomic nervous system is so complex that most of the time, it’s unconscious and regulating vital functions without you even being aware of it.
One of the most exciting components of this system is heart rate variability (HRV). HRV is the measurement of our heart rate variability as a result of our autonomic nervous system. It’s important to note that the in-between time heartbeats, called the R-R Interval, are not the variable measured, but rather the R-R Interval variation.
A healthy HRV shows that your heart rate is not varying much throughout the R-R Interval (variation between beats). This means your nervous system effectively regulates and maintains your vital signs, blood pressure, and other body systems.
A low HRV indicates a more stressed-out nervous system, which might cause an increase in blood pressure or other related body responses.
With a low HRV, there is only a weak sympathetic response, usually due to depression, stress, or low blood sugar levels. And it can impact athletic performance both during training and in competition.
HRV and athletic performance
Want your athletes to perform better? Improve their HRV. There is a direct correlation between the ability to induce a Heart Rate Recovery (HRR) and athletic performance.
For example, if an athlete is more likely to get injured after the last few days of anaerobic training, we might want to consider trying to keep their workload down. At the very least, you can be aware of this and adjust their practice accordingly. It’s a significant benefit having a baseline to use against when other athletes are injured and potentially begin to overtrain.
What a great way to tie HRV together. Not only can you use it as a predictor of future events, but you can also use it to see how your athletes are feeling and whether there may be imbalances in the nervous system.
The bottom line is that having a low HRV likely means that the sympathetic nervous system is dominating, resulting in a host of symptoms: over-training, burnout, poor performance, and increased risk of injury.
There are times when one branch is dominating (usually the sympathetic), which is a good thing. Like if you’re running a race, you want your body to focus on allocating resources to your legs (sympathetic) instead of digesting food (parasympathetic).
A higher heart rate variability suggests there’s more room for the sympathetic nervous system to kick in and rev things up; a lower HRV means the parasympathetic nervous system is dominating, which makes it harder to push past your comfort zone.
Parasympathetic vs. Sympathetic
Although HRV manifests as a function of your heart rate, it originates from your nervous system. Your autonomic nervous system, which controls your physiology’s involuntary aspects, has two branches, parasympathetic (deactivating) and sympathetic (activating).
The sympathetic nervous system works with the central nervous system to prepare the body for ‘fight or flight’ by increasing blood sugar levels, increasing heart rate, and constricting blood vessels. Some people may experience an increase in blood pressure.
The parasympathetic nervous system directly opposes the sympathetic nervous system, slowing heart rate, and increasing digestion. Not only that, it seems to help with pain, speeding up metabolism to remove the unwanted effects of stress.
Heart rate variability is a good measure of parasympathetic activity. If you don’t have the right amount of parasympathetic activity, your body’s autonomic system can’t respond quickly enough to change. The result is sub-optimal performance.
Heart Rate Training
The easiest way to understand heart rate variability is to listen to your heartbeat. Heart rate is the number of times your heart beats per minute. And it is an exercise intensity metric.
Heart rate training is an excellent tool for exercise prescription, endurance training, or keeping track of your fitness in real-time.
By monitoring your heart rate, you can better understand how hard you are working during exercise. In addition to this, heart rate variability provides a guide on how the heart works during rest. The heart rate variability ratio indicates your heart is going through a regular cycle.
HRV as a tool to monitor overtraining
When you see something exciting or stressful, a news headline, a fraudulent credit card charge, heart rate increases; breathing increases. It’s the fight-or-flight response. This is the way that your body is meant to function. But when we get triggered to it or train ourselves to make an activity a norm, it becomes the norm, and we ignore it, and we think it’s okay to yell. It’s okay to have negative emotions in social settings.