By now you’ve probably heard all the warnings about high cortisol, followed by an endless list of things you’re not supposed to do:
Don’t drink coffee on an empty stomach, don’t work out too much, but don’t work out too little. Don’t check your phone before bed, or first thing in the morning.
And of course, for every habit we’re told to give up, there’s a new one we’re supposed to pick up:
Start your morning with sunlight, swap your coffee for matcha, spend your evenings journaling instead of watching TV, and somehow find time to meditate.
At this point, it feels like we’re being told to rearrange our entire lives to avoid these “harmful” cortisol spikes. And ironically, trying to follow all these rules might be the most stressful part.
So before we start changing our routines, let’s understand what cortisol even does and when it can actually become a problem.
What is Cortisol?
Cortisol is a hormone your body produces throughout the day to regulate your energy, metabolism, and circadian rhythm. It naturally peaks in the morning and winds down throughout the day, and it plays an important role in how our bodies respond to stress.
Cortisol helps make stored energy available when you are exercising, haven’t eaten in a while, or are dealing with a stressful situation.
There is an important distinction to understand: a temporary cortisol spike isn’t the same as chronically elevated cortisol.
A temporary spike is beneficial and essential for our bodies to function properly. But when cortisol levels stay unusually high for too long, you may start to experience the symptoms you’ve been warned about: fatigue, poor sleep, muscle weakness, stubborn weight gain, and irregular or missed periods.
Now that we understand this difference, let’s look at what happens to cortisol throughout the day and which, if any, of the habits we’re warned about contribute to chronically elevated cortisol.
Cortisol: In the Morning
When you wake up, your cortisol naturally rises to help you wake up, feel alert, and take on the day.
These are common habits that might be adding to your body’s stress response in the morning:
Screen Time
When you check your phone first thing in the morning, it can contribute to brain fog and anxiety. Taking in so much information before you’ve had a chance to fully wake up and ease into your day can leave you feeling overwhelmed and add to your overall stress.
Alarms
A loud, blaring alarm can startle you out of sleep and set off your body’s stress response, raising your heart rate and cortisol. Switching to a gentler alarm sound is a small change that may help you start your morning feeling a little calmer.
Coffee
Caffeine causes a temporary cortisol spike and has lasting effects on your body for several hours. Drinking coffee on an empty stomach in the morning can push your cortisol levels up even further if you’re particularly sensitive to caffeine. Since your cortisol is naturally climbing in the morning, coffee first thing adds on top of that and can make you feel more stressed.
Keep in mind
Caffeine doesn’t affect everyone the same way. If you enjoy your morning coffee and feel fine, keep your routine.
Skipping Breakfast
When you go hours without eating, your blood sugar starts to drop. The longer you go without food, the more your body relies on cortisol to pull from your stored energy and keep you going. If you’re too busy for a full meal, grab something small. Even a few bites of food can help start your metabolism for the day and offset this stress response.
Forgetting Your Water
Throughout the night, you lose water through sweat and breathing. Dehydration is a stress on your body, and research shows people who don’t drink enough water regularly have bigger cortisol spikes when they’re stressed.
These are just a few common examples, and what feels stressful to one person might be relaxing to another. Maybe you ease into your day by drinking your morning coffee while watching TV. If that’s what helps you relax, cutting out coffee and screen time just to avoid a cortisol spike might be missing the point.
Over Time
While some of these habits can add stress to your mornings, that doesn’t mean they’re causing chronically elevated cortisol. What matters more is your overall stress and how your body responds to it over time (remember the key distinction). Small changes, like giving yourself more time in the morning or eating before heading out, can help support your body’s natural rhythm and make your days feel less stressful.
Cortisol: During Exercise
Exercise naturally raises cortisol to help your body meet its energy demands and fuel your muscles.
HIIT Workouts
HIIT Workouts often get a bad reputation for spiking cortisol and throwing off your hormones, especially for women. While it’s true that HIIT raises cortisol, it’s part of your body’s normal response to intense exercise. In this context, physical stress isn’t a bad thing! But your body does need time to recover from these types of workouts. Mixing lower-intensity workouts and rest days is important for you to get the benefits of HIIT without pushing your body to its limit.
Working Out Without Fuel
Exercise on an empty stomach can increase your cortisol response, especially during longer or more intense workouts. But an occasional fasted workout isn’t always harmful. For example, an intense workout first thing in the morning after a poor night’s sleep, followed by several hours without food, puts different demands on your body than a short walk after waking up.
Before you exercise, consider the intensity of your workout and whether you’re fueling enough to support it. Try your best to balance your training intensity with enough nutrition, sleep, and recovery so your body can grow stronger without overexertion.
Over Time
Consistently doing intense exercise without proper recovery, nutrition, and rest between sessions can place ongoing physical strain on your body and contribute to the prolonged cortisol excess we want to avoid. You may start to notice fatigue, soreness that doesn’t go away, and declining performance.
Cortisol: During the Day
Cortisol naturally declines throughout the day but can temporarily rise in response to physical and psychological stressors.
Some days are just busy. You’re rushing to meet a deadline, cramming for an exam, running between meetings, or barely finding time to sit down for a proper meal. We’ve all been there, but these everyday stressors can activate your body’s stress response, including a temporary rise in cortisol. Even without an immediate physical threat, something as simple as your never-ending to-do list can trigger this response.
Skipping meals can add another layer of physical stress. When you aren’t eating enough, cortisol helps your body maintain blood sugar by making stored energy available. This is a normal short-term response, but consistently under-fueling can affect how your body regulates stress over time.
Over Time
When busy, stressful days become constant, and you’re consistently skipping meals or struggling to find time to mentally unwind, your body’s stress response can become disrupted over time. Remember, recovery isn’t just physical. Your mind needs opportunities to rest, too. Taking breaks, making time for activities you enjoy, and finding ways to unwind can help you manage the effects of ongoing stress.
Cortisol: At Night
Cortisol naturally starts to fall at night as your body gets ready for rest.
Just as your body is beginning to wind down, certain habits can work against this natural process. Checking work emails, reading stressful news, or scrolling through content that leaves you feeling anxious can activate your stress response right when your body is preparing for sleep.
Side note
Even when the content isn’t stressful, spending time on your phone can keep your mind engaged and make it harder to fall asleep.
Research has shown that sleep deprivation can lead to higher cortisol levels the following evening, when they would normally be declining.
Over Time
Staying up too late or not getting enough sleep can throw off your body’s natural cortisol rhythm, sometimes keeping cortisol levels higher into the evening when they would normally be dropping. This pattern can make it harder to wind down at night, leaving you feeling more fatigued, having trouble concentrating, or overwhelmed the next day.
This can become a cycle: stress makes it harder to sleep, poor sleep makes it harder to manage stress the next day, and you end up carrying that stress into another night. To break the cycle, try to give yourself enough time to unwind and get consistent, restorative sleep.
These are just a few of the habits we’ve been warned about, but hopefully by now you can see the pattern. While most of them do cause temporary cortisol spikes, it’s important to remember the key distinction between temporary spikes and prolonged cortisol excess. This prolonged excess that we want to avoid doesn’t happen overnight or from one “cortisol-inducing” habit, but from when your body is consistently under physical and psychological strain.