What a Triathlete should know about Heart Rate Variability

Heart rate variability, or HRV for short, is a measure of your autonomic nervous system that is widely considered one of the best objective metrics for physical fitness and determining your body’s readiness to perform.
What is Heart Rate Variability?
Heart rate variability is literally the variance in time between the beats of your heart. So, if your heart rate is 60 beats per minute, it’s not actually beating once every second. Within that minute there may be 0.9 seconds between two beats, for example, and 1.15 seconds between two others. The greater this variability is, the more “ready” your body is to execute at a high level.
Using heart rate variability can help diagnose and treat many health conditions. This is a common medical tool used to track the heart’s activity and is a key part of the autonomic nervous system. It’s often invisible and is one of the most important indicators of current and future health problems.
Why is HRV a Sign of Fitness?
When you have high heart rate variability, it means that your body is responsive to both sets of inputs (parasympathetic and sympathetic). This is a sign that your nervous system is balanced and that your body is very capable of adapting to its environment and performing at its best.
On the other hand, if you have low heart rate variability, one branch is dominating (usually the sympathetic) and sending stronger signals to your heart than the other. There are times when this is a good thing–like if you’re running a race you want your body to focus on allocating resources to your legs (sympathetic activity) as opposed to digesting food (parasympathetic activity).
However, if you’re not doing something active low HRV indicates your body is working hard for some other reason (maybe you’re fatigued, dehydrated, stressed, or sick and need to recover), which leaves fewer resources available to dedicate towards exercising, competing, giving a presentation at work, etc.
To look at it another way, the less one branch is dominating the other, the more room there is for the sympathetic (activating) branch to be able to come in and dominate, which is why high HRV suggests you’re fit and ready to go.
Health and Other Applications of HRV
Beyond using heart rate variability as a fitness metric, it also has many applications when it comes to our overall health and well-being. Tracking your HRV can help you gain a better understanding of:
- Nutrition
- Sleep
- Stress levels
- Mental health
- Warnings of signs of sickness
- Risk of disease
For example, if your daily routine is unchanged but your HRV drops, it may be an indicator of increased stress or oncoming illness. Or, if you’d like to see the effect a new diet has on your body, the impact will be noticeable in your heart rate variability.
It’s a Sign of Current or Future Health Problems
Generally, heart rate variability is a good indicator of your health. It indicates how your body is dealing with the stresses of daily life, and it can be used to gauge your health status from time to time. A lower HRV can indicate that you are more vulnerable to stress. If your HRV is low, you should consult a doctor about possible health issues.
The heart rate has many different functions, including breathing and respiration. The heart rate is generally faster when you are active, such as running, and slower when you are resting or relaxed. It is the heart’s job to pump blood to the muscles, which in turn can be used for oxygenation. During breathing, the heart rate increases and slows down to accommodate the exhalation process. A high HRV may indicate you have less stress and better heart health. A low HRV may indicate that you are experiencing a prolonged stressful situation.
The heart’s rate changes depending on your activity, and the heart’s rate may also change depending on your age. HRV can be affected by a variety of factors, including medications, congenital heart defects, and smoking. It is important to monitor your heart’s performance so that you can catch any health problems before they become life-threatening. It is also a good idea to pay attention to your heart rate when you have a medical emergency.
It’s a Measure of your Heart Activity
Often referred to as HRV, heart rate variability is a measure of the timing between consecutive heartbeats It is one of many cardiovascular health indicators that is used to determine a person’s wellness level. Generally, higher HRV is associated with better health and wellness. However, reduced HRV is a marker of stress-related illness and cardiovascular disorders.
In humans, the heart beats approximately 115,000 times per day. This number can be influenced by various factors, including activities, age, gender, and lifestyle.
When the body is in a relaxed state, heart rates slow down. This relaxation response is the result of the parasympathetic nervous system. It is also called the “rest and digest” system. It helps the body reduce blood pressure, relax the heart, and restore homeostasis.
Heart rate variability is typically measured by an electrocardiogram machine. The device can record the heart rate for up to 24 hours. It provides instant feedback to the patient. In addition, HRV can be influenced by external stressors, such as noise exposure.
Low heart rate variability is a marker for ventricular arrhythmia and cardiovascular disorders. It is also a predictor of all-cause mortality. It is common for people with high resting heart rates to have lower HRV. Those with lower HRV are usually more stressed and less resilient to stress. In addition, people with low HRV are more susceptible to cardiovascular diseases, including heart attack, heart failure, and stroke.
It’s a Popular Clinical and Investigational Tool
Even though heart rate variability is a comparatively new technology, its application in research and medicine has been widespread. Heart rate variability is not just about gauging blood pressure, it is also an important indicator of the health and fitness of the human body. It may also offer a noninvasive way to signal a possible autonomic nervous system imbalance.
Heart rate variability (HRV) is a statistical measure of the frequency and length of time between heartbeats. It is measured by an electrocardiogram (ECG), which is an electrical tracing of the heart’s electrical activity. The ECG is not a complete measure of the heart’s activity,
The best way to measure HRV is through the use of a specialized device. These devices look similar to a pulse oximeter and are attached to a chest band. The devices are capable of measuring heart rate variability for up to 24 hours. They are usually inexpensive and easy to use. The best results are obtained when the monitoring time is lengthy.
The heart rate is controlled by the autonomic nervous system, which is divided into the sympathetic and parasympathetic branches. The parasympathetic branch controls the heart rate and blood pressure and releases epinephrine and norepinephrine. The sympathetic branch is also referred to as the “fight or flight” mode. This is why the heart rate is so fast and is commonly associated with high blood pressure and heart arrhythmia.
It’s Undetectable
Using a device to track heart rate is an important part of keeping your heart healthy and happy. In fact, tracking heart rate is one of the best ways to discover if you have a heart condition. This is especially true if you have had a heart attack or other maladies like a heart transplant. It is a good idea to track heart rate at least once a week. The average human being has around 50 heartbeats in a day. This translates to a total of around 650 heartbeats in a week. Keeping track of your heart rate can help detect heart attacks and heart problems before they happen. Thankfully, there is a plethora of devices to help track your heartbeat, from wearable devices to smartwatches. The best part is they are surprisingly affordable. Moreover, a wearable device like this can track your heart rate in real time and send alerts to your smartphone.
It’s Associated with Respiration and Low-Frequency Oscillations
Having a high heart rate variability indicates that the body is resilient. However, if the variability is very low, the body is less able to adapt to changes in the environment.
The heart rate is affected by the activity of various body systems. The parasympathetic nervous system, for example, tells the heart rate to slow down and relax. It also lowers blood pressure. This type of activity is responsible for the very low-frequency component of heart rate variability.
The parasympathetic nerves are responsible for the main source of heart rate variability. However, the high-frequency component is also influenced by sympathetic activity.
Normally, the heart rate varies based on respiration and the body’s needs. When the body is stressed, the heart rate increases. This increases the time between beats. However, the body can handle these changes with other mechanisms.
The parasympathetic nerves also control heart period changes. It takes effect much faster than the sympathetic nerves. When the fight or flight mode is over, the parasympathetic nerves take over and the heart rate slows down.
The parasympathetic nervous system is also responsible for the very low-frequency component of heart rhythms. These low-frequency oscillations are generally 10 seconds. The frequency of these oscillations is usually around 0.1 Hz.
The high-frequency component is in a range of 0.15 to 0.4 hertz. This frequency is often referred to as the respiratory band. It reflects the vagal and sympathetic activity of the heart.
It’s Controlled by your Autonomic Nervous System
Often thought of as an arrhythmia, heart rate variability is actually a noninvasive way of monitoring the functioning of your autonomic nervous system. Besides being a measure of physical fitness, it can also be a sign of mental health issues.
The autonomic nervous system is a set of nerves that governs your heart rate and other involuntary physiological processes, including digestion and breathing. It’s divided into two branches: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system, which carries out the “fight-or-flight” response, kicks in when we’re anxious or in danger. Its signals are stronger than those of the parasympathetic nervous system, which is responsible for the relaxation response.
Both the sympathetic and the parasympathetic nervous systems are essential to the human body’s function. When our body senses danger, the sympathetic nervous system kicks in and releases adrenaline and other hormones that increase our heart rate and blood pressure. The parasympathetic nervous system then takes over and restores homeostasis.
People with a low heart rate variability are vulnerable to stress and more prone to cardiovascular disease and depression. They may also have a decreased ability to handle acute stress.
A high heart rate variability is a sign of a healthy autonomic nervous system, allowing the body to adapt to the environment quickly and effectively. It’s also a good indication of mental health.
How to Improve Heart Rate Variability
Methods for increasing HRV include the following:
Intelligent Training. Don’t overdo it and push too hard for too many days without allowing your body to recover (see below).
Hydration. The better hydrated you are, the easier it is for your blood to circulate and deliver oxygen and nutrients to your body. Aiming to drink close to one ounce of water per pound of body weight each day is a good goal.
Avoid Alcohol. One night of drinking potentially decreases HRV for up to five days.
Steady Healthy Diet. Poor nutrition has adverse effects on HRV, as does eating at unexpected times.
Quality Sleep. It’s not just the amount of sleep you get that matters, but also the quality and consistency of your sleep. Going to bed and waking up at similar times each day is beneficial.
Auto-Regulation. In general, trying to get your body on a consistent schedule (in particular with sleep and eating to align your circadian rhythm) is helpful. Your body does things more efficiently when it knows what’s coming