Stress comes at us from all directions, and it’s not always the usual suspects like work, finances, and global strife that derail us. Even things we find enjoyable and meaningful—exercise, hobbies, volunteer work—contribute to our overall stress level as we struggle to fit everything into our busy lives.
As we’ve discussed before on the blog, stress adheres to the “Goldilocks principle.” Too much and too little stress can both get you in trouble. The goal is to find that just right sweet spot somewhere in the middle. In the right amount, stressors challenge us to adapt mentally and physically to our circumstances, prompting us to become stronger and more resilient.
I find the analogy of the “stress bucket” helpful in conceptualizing stress. This is a shorthand way of saying that all the stress we face, from sources we’d label both good and bad, gets thrown into the same pile. Our body has to process all of it. Ideally, we’d have more “good stress” (exercise, hot and cold exposure, stimulating mental challenges, etc.) than “bad stress.” Even then, though, we need to keep an eye on our total stress load to make sure the bucket doesn’t overflow.
There are both objective and subjective metrics you can use to track your stress over time. Objective variables are things you can measure with tools—biometric devices, blood tests, and such. Subjective measures are your personal judgments. An outside scientist can’t validate them, but subjective data are still very valuable. The goal of tracking these metrics is to prevent a health crisis and keep stress in a healthy range.
Here are some metrics you can use to track and monitor stress:
Heart Rate Variability (HRV)
Heart rate variability (HRV) is arguably the most accurate and most popular way to measure stress at the moment. HRV tracks autonomic nervous system activity—the branch of the nervous system that regulates the internal organs, maintains homeostasis, and prepares the body for action. The autonomic nervous system is divided into the sympathetic (“fight-flight-freeze”) and parasympathetic (“rest-and-digest”) nervous systems. In a perfect world, the sympathetic nervous system is activated when we have to rise to a challenge like interviewing for a new job or swerving to avoid an oncoming car. However, we generally want to walk around in a calm and relaxed state thanks to the parasympathetic nervous system predominating.
Unfortunately, that’s not how it works for most people. Chronic stress from all areas of our lives keeps the sympathetic nervous working overtime, pumping out adrenal hormones like cortisol and norepinephrine to deal with the constant threat (or what the nervous system perceives as a threat, anyway). Over time, this perpetual state of high alert creates all manner of problems.
HRV tells you how active the parasympathetic nervous system is relative to the sympathetic nervous system. Higher numbers reflect a more relaxed, less stressed state. Wearable trackers like the Oura ring, Whoop bracelet, and Apple watch all measure HRV, or you can sync a heart rate strap to one of several phone apps. Some apps even allow you to use your phone’s camera to measure HRV so you don’t need any additional devices.
What is a good heart rate variability score?
The general rule of thumb is that a higher resting HRV is better, but there aren’t clearcut guidelines for optimal HRV scores. The prevailing wisdom is that you shouldn’t compare your score to other people’s. Rather, you should track your own HRV over time and learn what factors cause your HRV to fluctuate up or down. In other words, get to know your unique patterns, then take steps to increase your HRV (i.e., decrease your chronic stress) if appropriate. Tracking your HRV over time lets you see when things are headed in the wrong direction, perhaps due to a period of poor sleep, work stress, or overtraining.
What Your Resting Heart Rate Says About Your Stress Level
All else being equal, a higher heart rate—particularly a higher resting heart rate—indicates a more stressed-out state.
Heart rate is controlled by the autonomic nervous system, with higher heart rate indicating more sympathetic nervous system activity. This makes sense. Since the sympathetic nervous system gets you ready to fight or flee, it increases heart rate to pump more oxygenated blood to the muscles.
Resting heart rate used to be a go-to method of tracking stress, but now that HRV is so easy to measure, HRV is the preferred method. If you have an Oura ring, it gives you a daily Readiness Score that takes into account resting heart rate, HRV, and other factors like body temperature and sleep. Whoop offers a similar Recovery indicator.
How Stress Affects Sleep
Sleep disturbances are common when you’re stressed. Possible signs that you’re dealing with a lot of stress include difficulty falling asleep or staying asleep, getting too little sleep, sleeping more than normal, or insomnia.
You can measure sleep objectively using a wearable sleep tracker, or subjective assessments can often suffice. It’s pretty obvious when you’re not sleeping well, after all. It’s worth paying attention to fatigue, too, in addition to how much time you spend in bed and how well you sleep. Stress may affect your sleep cycles or sleep efficiency in ways you wouldn’t necessarily detect but which nonetheless leave you feeling unrested.1
Poor sleep is itself a physiological stressor, so the sleep-stress spiral can become a double-edged sword. The opposite is also true—getting good sleep can help equip your body to deal with stress. Making an effort to optimize sleep, especially during stressful times, is imperative. Check out these posts for tips about maximizing your sleep:
Cortisol is an adrenal hormone often called “the stress hormone,” although it is one of several hormones involved in the body’s stress response. Arguably, though, it is the most important as it triggers many of the processes we associate with the fight-flight-freeze response: mobilization of fuel (especially glucose), slowing digestion, facilitating increased blood flow to the muscles. It also plays other essential roles in the body not related to acute stress.
When you’re dealing with chronic stress, a blood, saliva, or 24-hour urine test (where you collect all your urine for one day) might show that you have either abnormally high or abnormally low cortisol.2 Some practitioners, especially in the functional medicine space, will also order a DUTCH test, which measures cortisol in the urine at five different time points throughout the day. (Repeated salivary cortisol tests can do the same.) When your HPA (hypothalamus-pituitary-adrenal) axis is working properly, cortisol follows a daily rhythm where it is naturally highest in the morning and lowest in the evening. Chronic stress can interfere with that rhythm and flatten the curve, meaning there is less variation in cortisol levels throughout the day. Studies have shown that a flattened curve predicts breast cancer survival3 and is associated with health problems like type 2 diabetes.4
I hear all the time from coaches who work with athletes across a variety of sports that no metric beats motivation to train. In other words, the best way to tell if they’re up for a training session is whether they want to do the training session. Mark says essentially the same in Primal Endurance. Tracking HRV, sleep, and heart rate all are well and good, but ultimately, how you feel is your best guide in terms of daily training decisions. (Yes, sometimes even the most dedicated individuals have to summon some willpower to get out the door. Still, seasoned athletes learn the difference between “I’d prefer to stay in my comfy bed” and “I need a rest day.”)
This same concept applies to other areas of your life. Instead of “willingness to train,” think of it as “willingness to participate.” If you consistently dread going to work, or if you feel like it’s a major struggle to prepare another dinner, that’s a sign you’re overstressed. And yes, it’s extremely common—the norm even. That doesn’t make it good or right or least of all healthy.
Sure, you’re never going to be excited to do the boring parts of adulting like scheduling dentist appointments and remembering to give your cat her daily medicine. But if you consistently have the blahs about doing things you know are worthwhile—and especially things that are normally enjoyable like going out with friends—it’s time for a stress inventory.
Other Subjective Markers You Can Use to Measure Stress
Journaling can help you keep track of subjective ratings over time. To be systematic about it, make a list of germane variables and rate them on a scale of 1 to 5, for example. Use an app or even an excel spreadsheet to track your ratings. Otherwise, try free-journaling, then look back to identify patterns.
Emotional symptoms of stress
Anger, irritation, overwhelm, sadness, and generally feeling moody are all signs of chronic stress.
Forgetfulness and lack of focus
Acute stress may actually increase memory and attention because you need all your senses heightened when facing a threat. Chronic stress, on the other hand, interferes with cognition and may manifest as forgetfulness, brain fog, and an inability to focus.5 (These symptoms could also be related to sleep impairment, which is widely known to impair cognitive functioning.)
Food cravings or the opposite, lack of appetite
You might have experience with feeling either ravenously hungry—but mostly for sweet, salty, or fatty foods—or else having no appetite whatsoever during particularly stressful times in your life.
One of the things cortisol does is divert blood flow away from the gut. Stress can also affect the microbiome.6 And of course, we don’t always make the best choices around food and alcohol when we’re feeling stressed. All these factors can manifest in various digestive or G.I. symptoms including stomach aches, constipation, diarrhea, nausea, and heartburn. People with chronic issues like IBS may also experience stress-related flares.
Aches and pains
When you’re chronically stressed, you also tend to hold tension in your neck, shoulders, jaw, lower back, hips, hands, and/or feet. Some people believe that you can diagnose what types of negative emotions you’re experiencing based on where you feel the most tension or pain. Whether or not that’s true, it’s certainly the case that stress can manifest as physical discomfort. In addition to aches and pains, stress sometimes triggers more serious issues like migraines7 and fibromyalgia flares.8
Don’t Let Tracking and Monitoring Stress You Out
Tracking and monitoring are supposed to help you gather data that you can use to head off health problems, make better decisions, ingrain new habits, or run self-experiments. On the surface, it seems like more information is always better, but there’s a catch. Namely, the tracking and monitoring can itself become stressful. Too much reliance on data from trackers can also disconnect you from your intuition about what you need.
A perfect example of this is food tracking. Weighing and measuring food can be extremely helpful if you’re experimenting with a new eating strategy like a keto diet. Likewise when you’re trying to find out if certain foods are triggering health problems. However, it can quickly become tedious and take the joy out of cooking and eating. Worse, it may make you feel like you aren’t allowed to listen to your hunger and satiety signals because you are “supposed” to eat a given amount.
In other words, there are pros and cons to self-monitoring. It’s always good to foster self-awareness and approach your day-to-day behaviors more mindfully. Just make sure that you aren’t obsessing over the data nor giving too much power to wearable devices. Tracking should make you feel empowered to make choices that support your overall health and well-being.
Finally, it’s worth noting that stress affects everyone differently. It might manifest for you in ways not mentioned here. Pay attention to the variables most relevant to you.
For tips on managing stress, check out these Mark’s Daily Apple posts:
Lindsay Taylor, Ph.D., is a senior writer and community manager for Primal Nutrition, a certified Primal Health Coach, and the co-author of three keto cookbooks.
As a writer for Mark’s Daily Apple and the leader of the thriving Keto Reset and Primal Endurance communities, Lindsay’s job is to help people learn the whats, whys, and hows of leading a health-focused life. Before joining the Primal team, she earned her master’s and Ph.D. in Social and Personality Psychology from the University of California, Berkeley, where she also worked as a researcher and instructor.
Lindsay lives in Northern California with her husband and two sports-obsessed sons. In her free time, she enjoys ultra running, triathlon, camping, and game nights. Follow along on Instagram @theusefuldish as Lindsay attempts to juggle work, family, and endurance training, all while maintaining a healthy balance and, most of all, having fun in life.