How do you know how much stress you're under? Your heart actually knows the answer.
“I have so much going on right now.”
“I’m under a lot of stress”
These are pretty typical answers when you ask someone the question, “how are you doing?” these days. Even with huge advances in technology that should make our everyday more efficient, work, family life and activities seem to keep us busier than ever.
About 25-30% of people in North America say they are under significant stress almost everyday1,2, and over 75% of people experience physical or psychological symptoms from this stress2. When people are in a chronic state of stress in their lives, it can lead to increased risk or worsening of serious health conditions like obesity, heart disease, Alzheimer's disease, diabetes, depression, gastrointestinal problems, and asthma. With this being such an issue in our society, how do we know how much stress we are actually under? How do we know when we are under too much stress or if we are managing it well? How can we measure this?
Most people determine they are too stressed by how the “feel”; they get a scratchy throat, have bags under their eyes or feel increasingly tired. These aren’t accurate ways to determine if you’re over-stressed and they usually mean you’re too late in trying to deal with it anyway. For a long time, there hasn’t been a way to objectively measure the amount of stress on is under. Luckily, there is now a fast, easy and accurate way to objectively measure your stress levels on a daily basis and track it over time: the variability of your heart rate.
Heart rate variability (HRV) is a biomarker that has been known in the scientific community for years but is just now being available to the consumer. Most people get confused about how this is different than just heart rate you can get from your heart rate watch. Heart rate (HR) is measured in beats per minute (bpm), which does not require exact times, just the average of the beats in a given time period. For example, a 60 beats per minute HR could mean 1 beat per second or it could mean an average of 1 beat every 0.5s, 1.5s, 0.5s, 1.5s, etc. While heart rate focuses on the average beats per minute, HRV measures the specific changes in time from one heart beat to the next, typically called the “R-R interval”. Two individuals could have the same heart rate, but very different heart rate variability.
In general, low HRV, meaning less variability of the heart beat from one beat to the next, indicates that the body is under stress, where a higher HRV usually means that the body has a strong ability to tolerate stress or is strongly recovering from prior accumulated stress. Therefore, HRV lets you know if you are managing stress well or you are dealing with too much stress and need to recover before you even experience any symptoms.
HRV is best used during a rested state, usually first thing in the morning or during rested activities such as meditation. It is a great tool for understanding overall health, resilience, and ability to tolerate stress from all sources. These sources include physical activity, lack of sleep, illness, feelings about your work and home life, financial situation, relationships, nutritional choices and anything else that classifies as “stress.”
HRV can be used as a daily check-in with the body to determine its readiness to tolerate stress on a given day. In addition, HRV can be used to determine how various lifestyle choices affect the resiliency of your body to deal with stress. The better choices you make regarding your physical activity, nutrition, physical and mental health, sleep and so on, the better resiliency you will have to all forms of stress, which increases your HRV.
If you want to know what your HRV is and want to start measuring it, here are some ways to start:
Elite HRV on iTunes or Google Play (Free) – The most downloaded and widely used smartphone app. It is free but requires external hardware. I recommended a Polar H10 heart rate sensor or Elite HRV’s CorSense finger sensor for accurate HRV measuring.
HRV4training on iTunes or Google Play ($13.99 USD) - HRV4Training is the first app to use this technique to measure your Heart Rate and Heart Rate Variability reliably, without requiring any sensor. It does this by used to detect changes in blood volume during a cardiac cycle, by illuminating the skin and measuring changes in light absorption using the camera
Whether the body is overloaded with life stress, you’re dealing with a chronic illness or are training too hard for that marathon, Heart Rate Variability will indicate when total stress load increases and decreases. By measuring HRV daily, it will be an extremely valuable biomarker to know what your body is doing, and what the right path is to a healthier, happier life.